SEAGULL F.A.Q. -Frequently Asked Questions

Here are our best answers to often asked questions including ideas to save you money, better understand your seagull outboard and enjoy the built in reliability of the "Best Outboard for the World"!  And its all FREE thanks to the British Seagull Shop, Shoreline Wa. USA and the support of  seagull owners around the world!

Charles A. Stearns - Authorized British Seagull Parts Stockist- Shoreline, Wa.USA


  1. What have I got ... ?

  2. How much is my motor worth ... ?

  3. Can I buy a new British Seagull ?

  4. What is my fuel mix... ?

  5. What is my spark plug... ?

  6. I think I need a new impeller... ?

  7. What should I carry for spares?...

  8. What on earth is a British Whitworth thread?...

  9. What is a displacement hull?...

  10. How can Seagulls have Five hp ratings with only two blocks and piston sizes?

  11. Seagull weights

  12. What size seagull do I need for my boat?

  13. I have a seagull which has not been run in several years - what should I do first? 

  14.  Should I buy an E-bay motor?

  15.  I think I need a new coil - No spark!

  16. What is the secret of Seagull Maintenance?

  17. What is the fuel mix for my British Seagull?

  18. How can I solve the electrolysis problems on my Seagull?

  19. I have a pressed steel tank and its rusting - What do I do??

  20. Capt Ron do you have an ebay store too???

  21.  What do I put in my seagull Gearbox?? (important)

22. The Greatest Evil with Seagulls...

23.How Exactly do I ship a seagull so that UPS doesn't destroy it?

24.Should I buy a new outboard or a used British Seagull? 

25. Are there any books or manuals about British Seagull engines?

26. My metal fuel valve on my gas tank is leaking gas!!! 





All seagull serial numbers start with a model code. For example FP stands for Forty Plus) If there is an "L" at the end of the model letter code this signifies a long shaft engine which in seagull land means that the engine is 6" longer than a regular shaft engine.  From 1963 onwards a letter and number code is used to denote the month and year of manufacture. The month codes are as follows

Jan  A, Feb B, March C, April D, May E, June F, July G, August H, September J, Oct K, Nov M, Dec N  (Note I and L were not used in the month letter codes)

From 1973 two letters were used for the month.  With this serial number you can obtain parts and information on your engine.  Its easy to make a mistake reading the number as all serial numbers were hand stamped. Sometimes a "C" looks like an "0" of an "F" might look like a "P" especially if the light is not good or the serial number is covered in grunge. For security purposes and to ensure you can obtain parts and information please copy your serial number down and keep it handy.  IF you understand how the seagull serial number system works you will easily be able to identify a seagull and when it was built and also know other things about it like fuel mix, gear lube, and spark plug gap. Also because so many parts on seagulls are interchangeable it is some times possible that one motor was made up from several others and that's when you see very interesting mixes which do not appear to match with the serial number - for example a motor that was once a long shaft may now be a regular shaft engine because somebody has switched the lower unit at some time!


(Normally referred to as a 2 hp seagull, featherweight or forty-minus, these engines were also referred to as a 1-2 hp model when hp ratings were revised and then in later models they were rated in foot pounds of thrust i.e. the model 45 produced 45 foot pounds of thrust at the prop. Its easier to refer to them as a "2 hp" !!! Many consider this model to be the best looking seagull as proportions are excellent and weight is quite low. They are a little harder to find than the 3 hp model because fewer were made)


Note on HP ratings: The HP ratings changed over the years. When you purchased the motor either from the original owner or from a seagull dealer you may have been told it was more powerful than the revised hp ratings now indicate. In past years there was great confusion in outboard hp ratings as different systems of measurement were used by each manufacturer. Legislation passed in the UK in the early 1970's resulted in revised hp ratings based on actual thrust at the prop. Confusion reigns supreme to this day on just how many HP seagulls produce. What confuses people is that a "little" 3hp seagull seems to have as much thrust as a modern motor twice its hp rating! Seagull has consistently advised that their motors are designed for displacement hulls NOT planing hulls where a higher speed motor is better. Just to add additional confusion to the subject if you are looking for a conversion factor between thrust and hp ratings forget it. There aren't any. Horsepower is a measurement of work done. Thrust is a measure of static thrust. Why don't we all agree that "hp ratings and seagulls" don't go together and leave it at that! Naturally few will agree with that so here goes....


(Normally referred to as a 2 hp seagull, featherweight or forty-minus, these engines were also referred to as a 1-2 hp model when hp ratings were revised and then in later models they were rated in foot pounds of thrust i.e. the model 45 produced 45 foot pounds of thrust at the prop. Its easier to refer to them as a "2 hp" !!! Many consider this model to be the best looking seagull as proportions are excellent and weight is quite low. They are a little harder to find than the 3 hp model because fewer were made)

SJM Forty minus   Mk 1 ignition 1955 to 1967 140 gear oil
F Featherweight Mk2 ignition 1967 to 1976 140 gear oil
GF Featherweight Mk2 ignition 1977 to 1978 140 gear oil
FS Featherweight Mk2 ignition 1978 to 1979 90 gear oil
GFS Featherweight Mk2 ignition 1978 to 1979 90 gear oil
EFS Featherweight Mk3 ignition 1979 to 1984 90 gear oil
EGF model 45 Mk3 ignition 1982 to 1984 90 gear oil
AF model 45 Mk3 ignition 1984 to 1985 90 gear oil
EF model 45 Mk3 ignition 1985 to 1989 90 gear oil
SEF model 45   1989 to 1990 90 gear oil
TSEF model 45   1990 to 1996 90 gear oil



(normally referred to as a 2-3 hp seagull, or forty plus or in later models as a model 55 they produce 55 pounds of thrust at the prop or approx 3 hp although to be precise one would need to refer to them as 2.5 hp+ models! The three hp or "forty Plus was the workhorse of the seagull line with many made. It produces a surprising amount of thrust for an engine of this size and when you wind it up past 3/4 throttle  it becomes a bit of a thrust beast!)


SJP Forty Plus mk1 ignition 1956 to 1967 140 gear oil
FP Forty Plus mk 2 ignition 1967 to 1979 140 gear oil
GFP Forty Plus mk 2 ignition 1976 to 1979 140 gear oil
EFPW Model 60 mk3 ignition 1983 to 1988 90 gear oil
EGFPW model 60 mk3 ignition 1983 to 1984 90 gear oil
FPC Forty Plus with Clutch mk3 ignition 1978 to 1979 90 gear oil
GFPC Forty Plus with Clutch mk3 ignition 1978 to 1979 90 gear oil
EFPC Forty Plus with Clutch model 55 mk3 ignition 1979 to 1989 90 gear oil
AFPC model 55 mk3 ignition 1983 to 1984 90 gear oil


"4 to 4.5" HP MODELS

(normally referred to as a 3-4.5 hp seagull The 4,5 and 6hp seagulls all share the 102 cc large block. There is a huge difference between say a 2 hp featherweight and a 5.5hp long shaft with the big 11"hydrofan on it)


LLS century 100 1956 to 1967 Mk1 ignition 140 gear oil
W century 100 1967 to 1973 Mk2 ignition 140 gear oil
CP century plus fixed drive 1957 to 1967 Mk1 ignition 140 gear oil
CPC century plus clutch 1967 to 1969 Mk2 ignition 140 gear oil
WP century plus clutch 1959 to 1967 Mk1 ignition 140 gear oil
WPC century plus clutch 1967 to 1973 Mk2 ignition 140 gear oil


"5 to 5 1/2" HP MODELS

(normally referred to as a 4-5.5 hp seagull and a model 110 and then a model 90 (reflecting foot-pounds of thrust), also previously referred to as a 6 hp seagull...confusing isn't it!)


S Silver Century mk 1 ignition 1966 to 1969 140 gear oil
WS Silver Century mk2 ignition 1969 to 1979 140 gear oil
WSC Silver Century,clutch mk2 ignition 1978 to 1979 90 gear oil
ESC Silver Century, clutch model 75 mk3 ignition 1978 to 1990 90 gear oil
SP Silver Century Plus clutch mk1 ignition 1966 to 1969 140 gear oil
SPC Silver Century Plus clutch mk1 ignition 1966 to 1969 140 gear oil
WSPC Silver Century Plus clutch mk2 ignition 1969 to 1979 140 gear oil
ESPC Silver Century Plus clutch model 80 mk2 ignition 1979 to * 90 gear oil
EFNR Silver Century Plus clutch model 110/90 with reverse mk3 ignition 1979 to 1991 90 gear oil


The really old seagulls - the model 102

Occasionally we get requests to identify the older model seagulls called the 102 model. This model (equipped with a one piece round cylinder head) was manufactured for approx 35 years prior to the appearance of the classic square head seagulls (equipped with the square aluminum heads).  Some model 102's were manufactured up to 1973 but most are older engines from the late 1940's and 1950's. The clutch drive models had a C in the serial number hence AC, TC, WC are clutch drive model 102's. The same letters were repeated with a "D" to indicate these engines were direct drive models ( i.e. no clutch)  so we had AD, TD and WD. Finally the higher hp 102's were designated as 102 Plus engines and had an H designation hence AHC, THC and WHC letters appeared in the serial number.   Although many parts are still available most of these engines are getting rather long in the tooth for dependable every day use and we see fewer of them each year. All use 140 weight gear oil and have the villiers MK1 ignition system. 

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How Much is my motor worth... ?

There is a show on TV called the Antique Roadshow where hopeful people drag in stuff they have picked up at garage sales for pennies, and hope to find that it is worth thousands of dollars!!  We all dream of doing this! We also get asked all the time "What is my motor worth?"  We are not antique dealers. A British Seagull is a working motor. If you require a valuation of a motor from a collectable perspective, an antique dealer is your best bet for a professional appraisal of its value.  Here is how we value a motor:

1. We inspect it and check it for:

We can't do that without actually seeing the engine and putting it thru certain tests. So there is no way to place a value on your motor without seeing it. That would be like phoning your doctor and saying "I'm not feeling well - what's wrong with me???"  Less you doubt me, I have had owners approach me with engines that were described by them in good faith as being "in good operating condition" only to inspect it and find the blocks were cracked or major components were missing! We never place a value on an engine without first seeing it, inspecting it and testing it and so if somebody has told you the British Seagull Shop said it was worth $xxx dollars then that simply is not true. 

You can value your motor by considering the following:

There are many ways to value a motor. A motor which was "Gramp's motor" and is still in the family is, in our opinion, priceless. A motor (or spousal unit) that you had 30 years ago and still have today, is priceless. A motor that you took with you when you took your small sailboat to the South Pacific is ... priceless. We understand seagulls, and putting a value on one is not something you do from a strict accounting perspective.


In summary - How much is my motor worth? - is a tough question unless I can see it and test it. If your motor is working and in good condition, take a look around at the cost of a new replacement motor of the same hp rating. A used motor of 10 hp or less will very seldom sell for more than 50% of the new replacement cost. The reason for this is that if a buyer decides to pay over 50% of the value of a new motor he starts to consider the advantages of buying new - the warranty- the fact that all parts are new- the fact that the latest technology is available, start to be factors in the buying decision.  Hope that helps!.


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Can I buy a new British Seagull ... ?

Sadly, no. Since 1996 British Seagull no longer produces engines. The British Seagull Dealer network has been closed down. Parts continue to be available for most models via the parent company, Sheridan Marine in the UK, who has been very good about maintaining a spares inventory. British Seagull Stockists are also available in locations around the world. Stockists maintain an inventory of British Seagull parts and can order parts from British Seagull in the UK. Individual owners can also order directly from British Seagull UK.  Supplying parts for motors which have been out of production, some for many decades, is a difficult and expensive task. On the good side, a British Seagull is one of the few engines in the world where you can still get parts for motors produced nearly half a century ago!  One of the reasons that British Seagulls are no longer manufactured is that they were a high quality product that was relatively expensive to manufacture compared to more technologically-advanced motors built of cheaper materials.  Very occasionally, we find a motor with very low hours on it and that's about as close as you will get to buying new. 

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What is my fuel mix ... ?

There are three possible answers here. Please note that you MUST use the correct fuel mix for your motor or you will ruin it. The fuel mix MUST be fresh. As a rule of thumb a seagull can use more but not less oil.


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What is my spark plug... ?

A Champion D-16 can be used in all British Seagulls. If you have the Mk 1 and Mk 2 ignitions, then you use a gap of .020". If you have the Mk3 Wipac ignition, then your gap must be no less than .035"  You should always carry a spare plug as it is the easiest fix on a seagull. Note that the very early seagulls - the 102 styles specified a gap of .015 to .018". This was due to the fuel used at the time and now a gap of .020" is recommended.

The Mk1 and Mk2 ignitions were made by Villiers and are found on most of the classic seagulls. The type 1 has a separate condenser. The flywheel on the Mk1 has three openings at the top. The Mk2 has a encapsulated coil and condenser. The flywheel on the Mk 2 has two openings at the top. An easy way to tell the difference is that the Mk1 is silver and the Mk2 flywheel is a gold colour. After 1978, the WIPAC Mk3 began making its appearance. This is a breakerless CD ignition system. These motors are sometimes called the "blue caps" as the top of the motor is! If you have a seagull with the breakerless Mk3 system your plug gap is a minimum of .035". The flywheel will be silver. Finally the MK4 breakerless CD system is the one with a groove in the outer surface of the flywheel and it also is silver in color. 

The "original" plug used in a British seagull was a champion 8 common. This big plug could actually be taken apart for cleaning. There was also a Lodge plug with a pink insulator that was used for a while.   Its possible you will also find a champion D9 or D21 which is a different heat range than the D16. We recommend the champion D16 for all seagulls. You should have a spare plug and probably two because this is the easiest repair you can make to your ignition system. (They are offered on our ebay store in packs of two)  When inserting the plug be sure to slightly lubricate the threads and use only your hand to start the thread. You really don't want to cross thread the steel plug threads into the soft aluminum head. Also do NOT over tighten the plug. 

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I think I need a new impeller... ?

Maybe not!. When you are testing the cooling system in a seagull with a direct drive ( no clutch) in a small tank or bucket you need to take the prop spring and prop off. You also need to ensure that the water level is up past the gear box to about 2 inches up the down tubes (the drive shaft casing is the thin one - the silencer or exhaust tube is the fat one). There is a reason for this. A seagull has a hard plastic impeller. The older ones are aluminum. The impeller is fitted by a friction fit to the drive shaft which turns the prop. But, unlike nearly every other "modern" impeller design, the seagull impeller does not actually touch the pump body. The good part about this is that there is practically no wear on this part unless you operate in sandy water conditions. The bad part is that it will not pump a water & air mix and its not particularly good at pumping at 1/4 throttle and below. When you are testing the engine in a bucket, air will be mixed in to the water and the pump won't work. Note:  if your motor has a clutch it is not necessary to take the prop off -simply put the gear shift into neutral. .

The exit hole for the cooling system is a pencil sized hole at the back lower surface of the cylinder block. When you have the engine started, you should get a nice clear stream of water at half and three quarter throttle and all is well. If not, back flush with a garden hose pressed against the cooling exit hole and try again.(you will get wet so ask the spousal unit to do it). Also try backflushing against the three horizontal slots in the exhaust housing where water enters the water pump area. (Don't back flush up the exhaust port as that leads into the cylinder and combustion chamber) Compressed air sometimes works too. What happens is that rust scale flakes off the inner surfaces of the water jacket and collects in the passages thus restricting water flow. By back flushing you remove some of the scale and re-establish water flow. You may not get very much water at slow speeds and this is something to think about. When operating at very slow speeds, your motor may not be getting very good cooling. You should increase the rpm's of the motor every once in a while to ensure that cooling water is getting thru. At a certain point even back flushing will not re-establish water flow and that's when you need to disassemble the engine and remove the cylinder, then remove the aluminum head to clean it out. Although not terribly difficult it will take you a bit of time to do and there is always the problem of corroded fasteners breaking off etc. You really should purchase the service manual for this operation. 

If you are operating the engine and notice there is no cooling water getting thru, STOP! Check for a blockage at the water inlet - perhaps a plastic bag or bit of kelp?  There is a very good chance that an engine without cooling will crack its block.  This is an expensive repair that can easily be avoided if you operate the motor correctly.

Please note that the 102cc seagulls (the 4,5,6hp) have many more problems with cracked cylinders than the 64cc seagulls ( the two and three hp models). So it is even more important to watch the cooling flow if you have the big block seagulls. From personal observation, the cracks appear to start on the bottom of the cylinder in the metal casting around the exhaust port and then cracks begin to appear in the water jacket are and they are then visible from outside. By this time the cylinder is toast to speak. My guess is that for every 10-15 large cracked cylinders I only see one small cracked cylinder!.

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What Should I carry for Spares?

This depends on where you are going. A trip offshore for several months will require a different set of spares to be safe and prepared. Everyone should carry the following:

When working on your motor, take it OFF the transom and place it inside your vessel as there is much less chance of dropping the parts overboard. If you are working on the carb you can take it off and work on it inside the boat. Trust me - this will save you lots of problems. Little parts seem to have a death wish and love to jump over the side to Davey Jones's Locker!


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WHAT on Earth is a British Whitworth thread??...

One of the first things that you will notice when working on your British Seagull is that your tools don't seem to work! This can be disappointing especially to those with large and expensive tool kits. It's also one reason why some mechanics hate to work on them. British Seagull uses a British Whitworth thread pattern for all its fasteners. There are two major thread patterns the in world today- SAE and Metric. But in the years prior to 1973 the British used the whitworth thread on all their mechanical equipment including the British Seagull, the classic British Motorbikes like Triumph, Norton, BSA etc. and cars such as the MG etc.(Note the British also had thread patterns for motorcycles too and at one time had several thread patterns but we are trying to simplify the discussion here)

Sir Joseph Whitworth, an engineer, proposed this thread in 1841. This was the first standardized thread and quickly caught on in England.  The principal features of the British Standard Whitworth (BSW) thread form are that the angle between the thread flanks is 55 degrees and the thread has radii at both the roots and the crests of the thread.. The British Standard Fine (BSF) thread has the same 55 degree profile as the BSW thread form but was used when a finer pitch was required for a given diameter. If only the British had called BSF " BSWF" much of the confusion with whitworth would disappear but oh no they called it BSF (with no mention of "Whitworth"). Seagull fasteners use BSF threads.

Update December 2004  I received this email from Brian Eves in the UK last year and have decided to post it as he sounds like he understands the fastener situation better than most of us do so here goes ....( thanks Brian!!)  If anybody else has some input on this please e-mail me and perhaps we can have the definitive answer on a topic that most of us find confusing!  I suspect that a complete understanding of British Fasteners is something beyond normal human ranges of comprehension. 

The reason for the confusion regarding BSW and BSF threads may result from the use of spanners the are marked with both treads. I have recently purchased some 1/4 and 5/16 BSF taps and dies which does confirm the thread size as being BSF. BSW is a much coarser thread, a good "engineers" website from the UK will give you the dimensions for each thread.
The seagulls use 11/4 x 1/4 BSF bolts to fasten the crankcase together, cylinder base are either 11/2 x 5/16 BSF studs or 11/4 x 5/16 bolts depending on what model. The studs for the tube are again 11/2 x 5/16 studs. I use cap screws to bolt the gear case to the pump flange, these are either 1/4 or 5/16 BSF.
Although the originals have a slotted head, i use the "Allen Key" type because using the right allen key there is no wear upon the bit that matters when you attempt to remove them. I have used a silicon sealant to cover the head and any hole at the base of the thread.   -Brian Eves

Update Feb 2005

Here is what I think is the final piece of the puzzle regarding BSW and BSF fasteners. The dimensions of the bolt heads and nuts are different for each thread pattern! This means that a 5/16 BSW socket will not fit a 5/16 BSF nut. However a 5/16 BSW socket is the same as a 1/4 BSF socket so will fit a 1/4 BSF nut. As you will realize right away there is a certain malevolent evil here, which on one level seems to defy any logic but which on another level allows one set of tools to be used on two thread patterns. Here are some sample equivalent sizes:

5/16 BSF  = 1/4"BSW

9/16 BSF =1/2" BSW

1/2 BSF=7/16 BSW 

3/16 BSF= 1/8 BSW

From a North American or European perspective when a mechanic picks up a SAE or Metric wrench he or she expects that wrench to fit the ONE size stamped on the wrench. The British mechanic knows that whitworth wrench will fit TWO sizes, BSW and BSF. 

Just remember that your seagull uses BSF fasteners and that whitworth tools will fit but that a 5/16 BSW wrench will not fit a 5/16BSF nut. 

You now know more about British Whitworth threads than you likely ever wanted to but it all boils down to this. The 55 degree thread pattern on your BSF  fasteners means that "normal" SAE or metric fasteners will not fit on your seagull engine. And although the BSF thread is a whitworth profile that is it has a 55 degree thread pattern, the coarse thread BSW fasteners will not fit either. Oh and just to confuse things Seagull eventually went metric and the newest seagulls have metric fasteners on them. All the old ones are BSF.    I will stop now!  -  Ron

Update March 12, 2005 I received this note from Paul Isserlis and thanks Paul for the good info!

Hi Ron
my set of wrenches are marked
  BSW  1/8   =  3/16 BSF
  BSW  3/16 =  1/4 BSF
  BSW  1/4  =   5/16 BSF
  BSW 5/16 =  3/8 BSF
  BSW  3/8  =  7/16 BSF
  BSW 7/16 =  1/2 BSF
  BSW 1/2   =  9/16 BSF
  BSW 9/16 =  5/8 BSF
  BSW 5/8   =  11/16 BSF
Am  sure they carry on the 1/16 difference , tho they may jump to an 1/8 difference in larger sizes  than Seagull's need. A story l heard was  that they dropped the size of heads on BSF bolts to save metal in one of the world wars. Will leave it you to work out how much weight is saved on a seagull!

British motorcycles used whitworth  w& f  long after cars switched to american.  In the late sixties  BSA  used whitworth , ces (cycle thread) ,  sae ,unc , and a couple of  their own design just to keep things simple.

If you think of BSF as "whitworth fine" or BSWF" it's less confusing!

Paul Isserlis


At this point anyone reading this FAQ on whitworth and seagulls will now have a much better understanding of the subject! As you see the key to understanding the muddled mess is that the seagull thread the BSF is the fine version of the whitworth thread pattern which is available as the BSW coarse pattern and the BSF fine pattern. Although whitworth tools fit each pattern the head and nut sizes between the BSW and BSF fasteners are different sizes so you can't use the same wrench for say a 1/4"BSF and 1/4" BSW bolt.   Thanks to Brian Eves and Paul Isserlis for helping us all out here! To prevent you having nightmares about this and waking up in the middle of the night screaming "WHITWORTH!!" keep a rubber mallet by your bedside and instruct the spousal unit to use it on your noggin should even the hint of the "W" word escape your lips...


BRITISH SEAGULL has a simple solution to the tool problem and offers an economical one piece combination tool that fits nearly all seagull fasteners! We have them here

Oopps I did it again!!! Update August 26th 2005

Just when you thought you knew everything you ever wanted to know about the fasteners used on seagulls.....Apparently there is yet ANOTHER type of thread pattern on the British Seagull engine. While all the major fasteners are BSF (British Standard Fine) the ones smaller than 1/4" BSF are something called BA( British Association) threads. So that pesky little fastener on the fuel valve, the tiny thing on the silencer tube and the little rascal on the villiers carb are yes....BA threads. 

Now I will stop.      ron


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What is a displacement hull?

British Seagulls are designed for displacement hulls only. They are a low-rpm, high-thrust motor, so have lots of torque but not lots of high-end speed. They work best with a displacement hull - that is a hull that displaces an amount of water equal to its weight while underweigh. (All boats displace their weight while at rest - that's Archimedes Principle.)  A planning hull is pushed along on the surface of the water and often just a small portion of the hull is actually in contact with the water. With a displacement hull, the maximum speed is the square root of the waterline length in feet, multiplied by 1.5.  For example, if your vessel was 25 feet long and had a displacement hull, the approx. maximum speed would be the square root of the waterline length, or 5, multiplied by 1.5.  That is, it would be 7.5 knots.  Examples of displacement hulls are dinghies, keel sailboats, workboats.

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How can Seagulls have five HP ratings with only two block and piston sizes?

You may notice that Seagull produced several engines with different hp ratings but with only two block sizes and only two different pistons. Unlike other motors, I have been told that seagull measured its' HP rating by the pull the motor could exert on a bollard. . There is a small block - the 64cc block that is shared by the two and three hp motors and then a 102cc block that is shared by the 4,5, and 6 HP motors. The gear ratio in the gear boxes and the size of the propellers determine the HP ranges within each block size. But remember horsepower ratings were measured differently over the years and it is difficult to say exactly how many hp each engine produced. In fact I ran across references to fractional hp ratings such as 1.5, 2.5, 4.5 and 5.5. Very confusing if one wants a single number.   Lets look at some examples:

Both rated horsepower engines were generated from the same cylinder and piston.

The prop is very interesting. It's called a "hydrofan" and at first looks deceptively simple. But take a closer look and you will see not square blades but blades with a compound pitch to them. Seagull also provided a modern looking "weedless prop" of more conventional design. The 11" hydrofan on the 6 hp seagulls is awesome! Imagine a 37 pound motor swinging an 11" five bladed prop! No wonder they have so much torque!

The huge advantage of keeping to only two block sizes is that many parts are interchangeable! A tremendous amount of excellent engineering went into your seagull. But don't go around spouting off gear ratios and prop diameters- a seagull is a working motor that likes to be taken out and used. Also, HP ratings changed over the years as different measurements methods were used. The bottom line is that your seagull with its lower gearing will provide a surprising amount of thrust at displacement hull speeds.  And is there anything more fun than seagulling? Probably not! Well ...maybe one thing. 

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Seagull weights?


(tank dry,bracket stripped for carrying)

26 12
FORTY PLUS (2-3 hp)

(tank dry,bracket stripped for carrying)

28 13
CENTURY 100 (3-4.5 HP)

(tank dry, bracket stripped for carrying)

35 15

(tank dry, bracket stripped for carrying)

38 17

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Matching any outboard to a particular vessel without actually trying it is a surprisingly difficult question because of the number of variables involved including; local conditions, load, hull shape, hull weight, hull condition, use, etc. but we can offer the following general guidelines:





3HP            A small dingy and a part decked 17 foot sailboat

3HP            If you don't own a boat but carry a motor in your car for rented or borrowed boats

3HP            As a second motor for fishing in 17 to 19 foot runaboats

4HP             As a second motor for fishing for 17 to 26 foot runaboats

5HP             Heavy workboats 14 to 17 feet

5HP             As an auxillary for boats of 2 to 3 tons

5HP             Full bodied boats , fishboats, scows 15 to 25 feet

5HP            As an auxillary for boats 3 to five tons


In terms of mounting a seagull, you need 13" of freeboard with the 2hp models and 15" of freeboard with others. In the case of long shaft models (stamped with an "L" in the serial number) the motor will be exactly 6" longer and the freeboard is 20" The freeboard is the distance from the water level to the top of the "C" clamps. Often sailors prefer the longshaft model. Normally the longshafts are more difficult to find because less were made. When your seagull is properly mounted it will be vertical when in operation. Also the carb should be in line with the down tubes NOT at an angle to them as this will only cause problems with fuel flow.

The best test is to put the engine on the boat and try it out! Local conditions, hull shape, fouling, weight, all vary. If you stay within the suggested range of HP and vessel length and type you should be happy. Seagulls have a legendary amount of thrust but can you use them in place of a 30 hp diesel on a 35 foot sailboat and expect the same propulsion? No. Can you use them when your 30 hp diesel throws a rod and all 500 pounds of it with its expensive and impressive German or Swedish engineering is Kaput! YES!!! Your little 37 pound seagull will get you back home if you have maintained it well - it will look after you! You may not be able to water-ski but it sure beats paddling!

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I have a seagull which has not been run in several years - what should I do first? 

Often a new owner will acquire a motor that has not been used in several years. It could be your motor, your Dad's motor, Gramps motor or a motor from an auction or garage sale or many other sources. It may be in various condition from excellent but dusty to pretty rough and seized. What to do - what to do? Start by looking it over. Get some good light and just look at it. Find the serial number on the right side of the crankcase and copy it down. Go to the serial number listings on this page and find our what sort of seagull you have. Does the engine appear complete? This is important as over the years parts can wander especially if someone was working on it and never managed to get it back together.  Then check over the engine block to see if there are any fine cracks. If the block is cracked the engine may still run but you will have cooling problems. The engine will still have a parts value - no matter what condition it is in. 

Then look inside the gas tank. What does it smell like? Old gas has a sickening smell and if you smell this - you pretty much know that the fuel system will need cleaning. There are two filters in seagulls - one in the banjo fitting which goes into the carb and one in the tank going into the fuel tap. Dump the old gas and mix up a fresh batch in the proper mix. Pre 1979 engines used a 1:10 fuel mix. From 1979 a 25:1 mix was used. Bing carbs used in 1978 and 1979 also are 25:1 carbs. To clean your fuel system methodically go thru each part of it with carb cleaner- don't forget the filters and take care with them as they can be cleaned. Clean the carb. Don't loose any fittings and don't over torque anything.

If all looks well try to see if the little beast will start. Try starting in a large bucket of water and have the water level approx two inches up the down tubes. Follow the starting procedure in the owner's handbook ( we supply them ) . Be sure the engine is pumping water at half and three quarter throttle and if not then shut down the engine. Take the prop off and try again. IF not pumping water backflush thru the exit hole at the bottom of the block with a garden hose. 

Note if you find that the fuel tap is leaking there are a couple of potential easy fixes. Let the fuel soak into if for a few hours and it may take up. Otherwise carefully remove the pull by removing and carefully storing that little fixing screw on it and boil it in boiling water for four minutes. If that doesn't work an emergency repair is five wraps of plumbers teflon tape an a small dap of grease. If all else fails Captain Ron will sell you a cork gasket rebuild kit for the fuel tap. The fuel taps are built to last forever and all you need do from time to time is replace the cork gasket!

If it starts things are looking good! Check out the gearbox ( the large nylon drain plug) and see what it looks like. For pre 1979 engines fill the gearbox with a straight 140 grade gear lube NOT grease. IF YOU USE GREASE YOU WILL DESTROY YOUR CROWN AND PINION GEARS.

The next step is to try it out on your boat. Here follow the directions in your owner's handbook for mounting the engine. Also be sure to have a lanyard attaching the seagull to your boat. And just for safety on land take out the security bar on the mount and prove to yourself that the entire mount will separate from the engine ( splash- glug glug glug) if you do that. 

Allow yourself a few hours of use to become familiar with your seagull before taking it on long trips. If the engine has not been run for years there may be a few small bugs to work out. Its a simple engine but like anything mechanical it requires a minimum amount of maintenance to ensure the great dependability these motors are capable of. 

The seagull is a working motor and likes to be worked! So as soon as you can get it out on your boat and start seagulling!

Resist that natural urge to do a "total breakdown and rebuild" of your seagull as nine times out of ten it won't need it. Each year I talk customers out of buying several thousand dollars worth of parts because they really don't need them. Aduhhh and I wonder why I have an empty piggy bank... But I sleep well at nights!

A few good things to have for your seagull- an operator manual, service manual, spare drive spring and spare sparkplug. And for your spousal unit - a small bag of gems, a wad of 20 dollar bills and a set of earplugs. (Just kidding- you need two wads of 20 dollar bills...-oh the earplugs are for the S. Unit as seagulls can be noisy...) You can purchase the bag of gems here

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Should I buy an E-Bay motor?

Seagull motors are regularly sold on E-bay often by people who are not the original owners who know nothing or little about them. Unfortunately, there are many seagulls out there that have been ill maintained, poorly repaired or just not repaired and they simply don't work! And they won't work until parts are replaced, old bad repairs reversed and more money spent! At the right price there can be good value here but there can also be great disappointment if your objective is to obtain a good seagull for a super price.

Here is the problem. As the price of good seagulls increases- the market rushes in with more motors not necessarily good ones- to meet the demand. People, anxious to cash in on the rising prices find engines in barns, basements and wherever -many of which haven't run in years. The secret is out - British Seagull made an excellent motor and IF well maintained they are extremely dependable engines. So boat owners want them! And you can still get parts for them!

 It is entirely possible to purchase a seagull on Ebay and get a good motor at a good priceUnfortunately, it is also entirely possible to purchase a seagull on ebay and get a motor that does not work, is missing expensive parts or has problems and to purchase it at an unreasonably high price when you factor in the additional parts and work you need to do to bring it up to good working condition. There is another problem.

 Motors are often shipped UPS or other freight carrier and often they break or damage motors if they are not packed exceptionally well. So what starts off being a very nice seagull could end up damaged. Also, at an auction, motors are usually offered "as is" and any problems are the buyers responsibility.  Given this information YOU need to make a decision. 

When we prepare a motor for resale in our shop we first repair any mechanical problems the engine might have. We give it a pre shipping test. It must start well by the first or second pull on a regular basis and it must pump water ( cooling system OK) well and the engine must work properly ( gears and powerhead). When we ship a motor we do so in our Mk10 shipping crate which effectively doubles the weight of the shipment but which also protects your engine against damage. In addition we provide support and information on Seagulls on-line 24 hours a day. All of this additional service results in costs and they are reflected in the prices on our engines however if you consider what you are getting we continue to provide very good value. As mentioned you can also obtain good value on Ebay - its just that your risks are much higher. 

If I was buying an engine on e-bay I would want the following information: If its not in the ad then ask the seller. A clear picture of the engine helps to get a better idea of its condition and appearance.

1. The full serial number - so that I could identify the engine from the FAQ page. This is the ONLY way you know what you are buying.

2. Does the engine produce a spark? ( If it does its most likely that the electrical system works)

3. Does the engine pump water? ( If it does its most likely the cooling system is fine)

4. Are there any fine cracks in the block? ( if so the engine will require major work)

5. Does the engine run? ( a lot of ebay engines are sold "as is" not running)

6. Is the engine complete - are there parts missing or are there parts damaged? ( we get many parts orders from Ebay buyers)

These are tough but fair questions to ask the seller. Some will hate you for asking and may simply refuse to commit themselves. Beware the cagey seller who tries to maximize his price by indicating his engine is in excellent condition and then covers himself by saying that he doesn't know much about them or hasn't had a chance to start it himself, or that it is sold "as is"  etc etc. Life is tough and many people on Ebay put huge volumes of found things on to generate enough income to feed the family. They want to sell and move onto something else and sell that. In fact - when you think of it - everyone sells something!

Using this information you can then set the price you are willing to bid for it. Every seagull in any condition has a value because of the parts interchangeability of these engines but a working motor is clearly worth more than a parts motor.

In summary, YES - Ebay is a good source of Seagulls -and Yes most sellers are pretty honest people especially the ones with lots of positive feedback.  Just be careful and try to manage your risks. And PLEASE...remember that as in any auction have an idea set in your mind BEFORE you bid on the maximum price you wish to pay. We occasionally see two determined bidders bid an item way beyond its fair market value.  Hope that all helps! Don't forget to check out our ebay store . Yes often store prices will be higher than auction or garage sale prices but get what you pay for. 

An alternative to an ebay seagull is our swap and shop page where you purchase directly from the owner. 

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This tip will save you lots of money IF you have a pre 1967 seagull (Villiers Mk 1 ignition system) and your engine has no spark. Some people immediately think that a new coil or a new condenser ( both a bit pricey) is required. Not so. Possibly you may need a coil but there are a few things you should do first. Change your spark plug with a new one and set it to .020" for all seagulls with either a Mk1 or Mk2 ignition system ( pre 1979 models) Check for spark again. Then clean your points off with 400grit sandpaper and some alcohol. Set the points for .020", spin the flywheel and check the gap again. Check for spark. Finally IF you have a pre 1967 seagull find a large socket to fit the dome nut and a drill or drill press. Take the spark plug out and spin the flywheel for approx three minutes at about 300 rpm. This will build up the condenser which is may be flat and - presto- like magic your Mk1 ignition system will work again!!! The High tension lead is also a possibility. Finally if you have done all that and still no spark ( and you checked the fixing screw in the magneto baseplate to ensure the base plate is not loose- this could affect the timing which is set at the factory) then start looking at the coil suspiciously. In a surprising number of cases the information here will save you the expense of replacing the coil.  Good luck! Remember this ONLY works with the older style Villiers Mk1 system NOT the later WIPAC Mk2 system.

Note if you have a Mk2 coil here is a tip from Seagull UK ( Sheridan Marine) "you could try hitting it with hot air from a hair dryer for a few minutes." If you have a Mk3 ignition system be sure that your spark plug is set at a minimum of .35" NOT the .020" of previous systems. 

A rule of thumb with all seagulls is that if you have a spark - the ignition system is fine. However as the information here indicates if you don't have a spark things may still be OK with a little work. That's why British Seagull is the Best Outboard Motor for the World!

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16 WHAT IS THE SECRET OF SEAGULL MAINTENANCE? If there was just one thing I could tell you about seagull maintenance it would be to be methodical.  In today's complicated, fast paced world we often need to take a systems approach to solving a problem and that means we need to understand if an entire system is working well. Not so with seagulls which are simple but clever little beasts. Clever because excellent engineering has gone into them to solve future problems for you. With seagulls you need to be methodical and that means doing one thing at a time and doing it well. If you are concerned about the fuel system start at the tank and clean it out, then go to the filters and the valve and then the fuel pipe and filters again and then the carb. In short, do one thing at a time until the entire system is back up to factory standards. Don't worry about seven different things -simply do one thing at a time and do the job right!. Follow the instructions in the service manual and owner's manual. They are there to help you. A well maintained seagull will be dependable and start by the second or third pull every time. It will be there when you need it most. 

 The worst enemy of a seagull is the owner or a series of owners who neglect to read the operator handbook or the backyard mechanic's who refuses to read the service manual. Every week in the shop we see examples of extremely poorly maintained engines where as a result the engine has stopped working.  For example, an owner has neglected to EVER check the gear box fluid (the manual says every 15 hours of operation) or has consistently used the wrong fuel mix or has replaced fasteners with the wrong thread type. And some of these people fancy themselves as knowledgeable boaters and good mechanics! Others, the very worst ones, claim they have "taken good care of their engines and that they are in excellent operating condition". But they are not! Sometimes the blocks are cracked or the gearboxes are packed with sand or salt crystals. Other times the cooling system is plugged and is not working.   Often these motors go on the market because " they don't work" so the misery of an ill maintained engine is passed on to yet another owner. And just to add to the irony these people often bad mouth the poor seagulls ("boat anchors") they have abused and even dumber people listen to them. Saying that " I could never get my seagull to work" is about the same as saying ..."Look at me I am a dumb ass and know nothing about outboards".

When you work on a lot of seagulls you begin to see patterns of abuse and while there are still a majority of excellent owners out there that do maintain their engines well and achieve that legendary Seagull dependability there are also those who should never own an outboard or anything mechanical requiring any service or routine maintenance. When we encounter one of the latter engines the challenge is to quickly determine what the previous owners have screwed up so we can redo the repair and get the engine working again. Can you imagine flying on a aircraft maintained by these people! Or how about a trip down a winding mountain road on a packed bus where these jokers have maintained your brakes!!  I don't think so. Well you don't want to be ten miles offshore when the tide turns and its getting dark and the main engine has quit and you turn to your "get you home" seagull only to find out that some joker has mickey moused it to the point where it will never start.  One of the particularly nice things about seagulls is that often even a poorly maintained one can be brought back to good operating condition if an owner is willing to invest in a service manual, read the operator handbook and complete or redo some basic maintenance. 

 I just recently refurbished a 10:35 gearbox on a forty plus seagull and here is what I found: 1. the owner had used the wrong gear oil. 2. the neoprene prop oil seal had been replaced with an "O" ring which didn't work. 3. The owner had placed the thrust washer between the prop collar and prop instead of between the front bushing and crown gear. He had then put in an old screw instead of the brass pin used to fix the collar to the prop shaft. He placed the prop washer on the wrong side of the drive spring.  Finally he had used  a sealant to "seal" the gearbox from water but this gearbox is designed to work with a water- oil emulsion. This is a perfect example of what I call a Mickey Mouse mechanic - a person who has no idea of what they are doing but does it anyway! Every single "repair" done was done incorrectly. All based on a lack of simple knowledge that could have been solved had he read the operator handbook and service manual. You can laugh but how would you like to fly on a an aircraft at 30,000 feet knowing that a joker like this maintained it! 

 The seagull handbook refers to this type of issue in a typically British Seagull way : (pg 4 British Seagull Handbook 24th edition)

" ...Almost all the ailments attached to outboard motoring can be accounted for by the attitude of..."It doesn't matter...any old plug will do...any old fuel... any oil thats available...mixed in any need to read the instructions, I know all about engines...never mind about fixing the engine on the boat properly, we're in a hurry...this'll do... that'll do" etc.,etc.

Let us say at once THIS WON'T DO. "

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 I hesitate to handle this topic here but will take a run at it cautioning the reader to be very very careful about the fuel mix they use in their seagulls. Many seagulls have been ruined over the years because owners did not read the manual and didn't put any or not enough oil in with the gasoline. Lets start with a definition. A fuel mix is a mix of gasoline and 2 cycle oil mixed in a specific ratio to allow the engine to work as designed and to prevent damage. Many of us understand that there are two types of outboards; 2 cycle engines and 4 cycle engines. The 2 cycle engines use a fuel oil mix and the 4 cycle engines use a straight gasoline. Note that the 4 cycle engines obtain their lubrication from oil that is recirculated inside the engine so less oil gets into the environment thru the exhaust and carb. That's the theory but of course we have all seen cars smoking and spewing oil from their enclosed system back into the environment. Also if the oil from a 4 cycle engine is not properly disposed of after use it too seeps back into the environment. All that aside, in an attempt to treat the subject at the grade three level ; 2 cycle engines are considered to be "bad" and as Martha Stewart would say four cycle engines are  a "good thing" . 

 All seagulls built before January 1978 were designed to run on a 1:10 fuel mix. (All seagulls will run on unleaded fuel ) That is ten parts gasoline to one part of 2 cycle oil. Now we start with the exceptions:

The only way you can be sure is to visually inspect either the taper needle or the jet. In the case of the taper needle the #2 or #3 stamping is very small and you may need a magnifier. 

A 10:1 mix can be achieved by mixing fuel in the following ratios

A 25:1 mix can be achieved by mixing fuel in the following ratios

(please note that we have not included the Imperial measurements here in an attempt to make the mixology just a little bit simpler)

I suggest that you mix your fuel yourself rather than trust it to somebody else who will almost be guaranteed to do it wrong. Never use a premix fuel from a marina. Find yourself a mixing container - mark it up and use it all the time. Most commercial mixing containers will not have a 1:10 mix so you will need to make one. Mark your portable fuel tank with the ratio of the fuel so that you won't use it for other machines. 

No matter which 2 cycle oil you use - the mixing ratio is the same. Don't let anyone tell you that less oil is required if a synthetic is used. Seagulls require the heavy oil mix to bring compression up and to keep the interior of the engine "pickled" during long periods of storage. This is why they have lasted so long and start so well after even years in storage!  And can use a non detergent straight 30 weight oil  IF the two cycle oil is not available. 

There you go. Clear as mud? Just to toss some real fear into you - if you use the wrong fuel mix - lets say putting straight gas into a seagull here is what will happen. The big bronze bushings will overheat and score causing the crankshaft and con rod to fail and the piston to overheat and melt it's sorry self to the wall of the cylinder resulting in a melt down of your engine. This will all happen as the flywheel is spinning at 4000 rpm. Perhaps you have seen those images of a nuke going off on some atol. Well - that's about it. The Germans have a technical term for it. "Kaput"  If you have gotten this far you are now getting pretty smart when it comes to seagulls. Most of it comes down to " read the manual" 

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British seagull engines are true marine engines constructed out of quality materials to function well in a marine environment. In salt water you have a special concern called electrolysis and that's when metals immersed in a salt water solution ( the electrolyte) set up itty bitty little electrical currents between the different metals. All metals are arranged in sort of a perverse electrical pecking order where the most noble metals will peck away at the less noble metals. Gold is a very noble metal but zinc is pretty much of a electrical peasant and gets eaten up very easily. That's why mariners attach zinc anodes to the other metal parts of their vessels so those parts will be saved and the zinc sacrificed. The thinking there is better to replace a $20 zinc once a year than have a hole develop in a steel hull or to have your rudder fitting disappear. The important thing here is that when you have different metals in contact with each other you have electrolysis going on and the least noble metal will corrode first. Keeping that thought look, at all the different metals you will find on you seagull engine; stainless steel, aluminum, pot metal, copper, iron, you name it and the seagull has it. Where the problems really start is with the fasteners which are mostly mild steel. They will corrode in place and often when you go to remove them the suckers will snap off! Seagull fasteners are in the British Whitworth thread pattern (BSF actually) and so your chances of finding them down at Canadian Tire or Wal-Mart or Pep Boys are precisely And you may need to drill the broken piece out which could mean re-tapping the hole. Again your chances of finding a whitworth BSF tap and die set when you need it are  If all the fasteners on your seagull are frozen and corroded then any service operation will be extremely painful and time consuming when it should be very very easy.   

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19. I have a pressed steel tank and its rusting - What do I do??

"Newer" seagulls were equipped with a pressed steel tank. The pressed steel tank was less expensive to manufacture than the older style round or oval brass tanks which were really works of art and made out of solid brass. The blue covered pressed steel tanks have something in common with all steel tanks and that is rust. If not maintained, the rust will basically destroy the tank. What to do - what to do? One good idea is to obtain a used brass oval tank. Yes most of them are dented and often the decals are long gone but they simply do not rust and they fit where a pressed steel tank will fit. Another approach is to refurbish your existing pressed steel tank and here I would like to share this note from Rob Puller of Gainsville Florida ,a fellow seaguller who used this method to refurbish his tank. 


"...We had a little discussion about rust removal from the fuel tank.  I've finally gotten it completely clean.  Here is what I did:
Filled tank with white vinegar and let it soak for 24 hours.  Filtered vinegar through a paint strainer and got about a half cup of rust.  Repeated procedure and got only a small amount of rust.  Tank still looked pretty grungy and I could see what appeared to be calcium deposits so I started searching the web.  Came up with the usual suggestions under "rust removal", then I tried fuel tank cleaner (or something similar) and found a company called POR-15, Inc. at  They make a number of metal preparation products and have combined several of them into a kit for cleaning fuel tanks.  I ordered the "Heavy Duty Cycle Tank" repair kit which includes a stripper (PORSTRIP) to remove any sealant that may have been added to the tank, a cleaner (MARINE-CLEAN) which takes out gum and varnish (and what I suspected to be calcium), a metal prep (METAL READY) which is an acid to remove remaining rust and prep the surface for... a tank sealer (TANK SEALER).  When the process was finished the interior of the tank looked brand new.  I then stripped the tank exterior with PORSTRIP, prepped it with METAL READY, and painted it with POR-15 rust preventive paint, followed by a coat of their BlackCote glossy black coating.  I obtained a new Seagull decal from, roughened the topcoat surface slightly and applied the decal, then sprayed the entire tank with Pelucid clear coat.  Tank looks brand new!"
This stuff wasn't cheap and it took a lot of time to restore the tank; however, this engine now looks like a new Seagull. 

Thanks Rob for your excellent advice and if any other seagull owners have solutions to maintenance problems please send them in and we will place them on the FAQ to share with other owners. 

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20. Ron do you have an eBay store too???

Yes we do and you can visit it by simply clicking below: 3 British Seagull Handbook 24th edition

"..The world of engine owners is divided into two classes...the vast majority are those that never run into trouble, and get heaps of pleasure, both for themselves, their families and friends, day in and day out... whilst the second class is a very small minority, always in trouble, causing misery, and constantly drawing on the good fellowship of other people for aid and assistance."


                21. WHAT DO I PUT IN MY SEAGULL GEARBOX? (there is a fair amount of detail in this one but its important stuff and worth investing a bit of time in)

140 wt Gear Lube is used on all seagulls mfg prior to 1979

Without a doubt, your seagull gearbox is one of the hardest working components on your engine.  Unfortunately, with many owners it is also the most neglected area for regular maintenance. Lets take the time to learn some basic information about your seagull gearbox that will extend the life of your engine and save you lots of trouble in the future!

 Lets start with the Seagull flywheel which is that part on the top of the engine that you can see rotating when the engine is running. At high speed the flywheel turns at approx. 4000 rpm and it is fixed to the top of the crankshaft with a dome nut. The driveshaft,  is connected directly to the bottom of the crankshaft,  and so it spins at the same speed as your flywheel. The drive shaft extends down into the gear box.

The job of the gear box is to reduce that rpm to a more manageable rpm at the prop and to reduce the direction of the rotation from the vertical drive shaft to the horizontal prop shaft. To do this there is a small diameter pinion gear attached to the bottom of the drive shaft and that meshes with a larger diameter crown gear which is attached to the prop shaft. What happens is that the drive shaft pinion gear must make anywhere from 2.1 to 4 turns - depending on the model gearbox- before the crown gear will turn once and so a reduction in rpm occurs. When you have two gears meshed together and spinning at high speed you have friction and heat is generated. The pinion and crown gears would quickly overheat and destroy each other without proper lubrication

 The seagull gearbox displays very clever design and is extremely well made of first quality materials. If maintained, it will last for a long long time- several decades of dependable use is not uncommon with a seagull!. 

Because the gearbox operates under water Seagull designed the gearbox to work in an oil- water emulsion where water and oil mix to act as a lubricant. The pressure developed by the emulsion also helps to keep the water out and the oil in. In pre -1979 British Seagulls there are no traditional seals in the gearbox. (there is a rubber "seal" which allows the passage of some liquid - but not a true seal which prevents the passage of any liquid) The prop shaft sits on two large phosphor bronze plain bearings thru which a small amount of leakage occurs. In any situation where you have a shaft spinning on a large plain bearing it is crucial that there be lubrication or the shaft will chew up the bearing and overheating and damage will occur. In my opinion it is not a good idea to replace the older style rubber washer with a more modern "dripless"seal as the original design calls for a slight amount of leakage at this point.  The original design is very inexpensive, lasts for years and is very easy to replace- its simple yet elegant engineering - its a seagull!

It is absolutely critical that the seagull gearbox be properly lubricated both to prevent damage to the prop shaft and plain bearings and to remove heat and prevent damage to the crown and pinion gears. Seagull recommends that the gear lube level be inspected every 15 hours of operation and lube be added as necessary via that large nylon plug in the front of the gear case.

Here is the problem. Often the owners manual will become lost or separated from the motor. Some owners simply neglect to do ANY maintenance on their motors. Some owners will place a non approved lubricant or grease in the gearboxes. The photo shows you what  a good  crown gear looks like and what will happen when grease is used in a seagull gearbox. What happens is that the gears form tacks in the grease and NO lubrication occurs causing the gears to be destroyed. Others will use a multi-grade lube oil - which tends to leak out faster or they will use a non approved gear oil that has additives in it which attack yellow metals ( like the phosphur bronze bearings in a seagull) or have anti foaming or other qualities which do not work well in a marine environment.  As a result many seagull gearboxes are damaged thru no fault of design or construction but thru owner neglect. The 2 hp gearbox being the smallest by volume is particularly sensitive to neglect. All seagull gearboxes will work perfectly fine and provide long and dependable service if approved lubrication is used.  

A problem with the 140 lubricant is that normally it is sold in five gallon pails and is difficult to source in many parts of the country. We have solved this problem and can supply it to you in 500ml bottles.  A 500 ml bottle would be good for approx 8 refills for a two hp,  2 refills for a 3 hp and one refill for the large 12:48 gearboxes found on the larger seagulls.  Please note that if your seagull was made AFTER 1979 it can use the standard 90 gear lube which should be easily available in your area. The reason for this is that in 1979 Seagull fitted seals to the propshaft which allowed the use of the lighter gear oil.

You can save on shipping by ordering other required spares ( spark plugs etc) at the same time but if you cannot find it locally we can supply it for you!

On other point in seagull gearboxes. Because there is a water- oil emulsion in the gearbox - when the motor is stored at the end of the boating season the water and oil separate out. This can be bad in a cold climate as the water can freeze and cause damage. It can also be a bad thing in a warm climate as water can sit on the gears and corrode them.  Its very wise at the end of the season to drain your gearbox and refill with fresh gear lube so that your engine is protected during storage and ready for the new season. Drain the old gas too or use a gas stabilizer.  Seagulls are wonderful engines that with just a little bit of help from you can easily achieve that legendary reliability they are famous around the world for! They should reliably start by the third pull every time and work all day without a complaint! 

One reason for selling any outboard is that " it doesn't work anymore" and so what you find on the re-sale market is a large percentage of poorly maintained motors that simply don't work or don't work very well. In our shop we find that for every four engines that we purchase for re-sale only one goes out as a refurbished motor because the rest can't be economically brought up to our shipping standards - that is a motor that is complete, works well and is capable of providing dependable service. The overwhelming reason for this is not the design or construction of the engine - its poor maintenance and poor repairs from previous owners.

This is likely more information than you ever wanted to know about your Seagull gearbox but its offered in the hope that some will take it to heart and extend the life of these well built engines well into this century. It's safe to say that a few pennies of the correct grade of gear oil is money well spent and will help you achieve the high levels of dependability British Seagulls are famous for!

                    We have 140 wt gear lube available at our Ebay store


British Seagull engines are extremely well designed, built with excellent materials and will provide excellent and reliable service for many decades with only minimal maintenance. They really are "The Best Outboard Motor for the World". There is one little problem in this fine planet we live on and that problem is "Evil". Good and evil seem to be balanced in most situations. Occasionally evil gets the upper hand and energy must be exerted to bring the universe back into balance. You stuff yourself with all that "good" food at the buffet only to find at the end of the week that you put on five pounds of "bad" fat. You have a "good" time at the party only to wake up the next day with a "bad" headache. Martha Stewart knows a "good thing" when she sees it but did a "bad thing" with some investments and went to jail.  It doesn't take long to figure out the great evil with Seagulls when you see them in the shop every day. Bad Fuel. 

Now fuel from the pump is not bad fuel. Usually. Its fresh and ready to go! Now I read that it is NOT the same sort of fuel provided decades before that tended to be more stable than today's fuel. But leave that concoction of gasoline and oil in your fuel tank for anymore than about three months and it goes stale and begins to break down. It changes from something we call "fuel mix" to something I call "crap". Sediments and varnish type deposits form and coat all interior parts of the fuel system from the tank to the carb. There reaches a point where the fuel will no longer combust and interior surfaces are plugged up and fuel will not flow nor will the carb work as designed. In short the bad fuel will actually stop the engine from working and the fix is to meticulously clean the entire fuel system out. Which takes time and money and will be the last thing you want to do when you want to use the motor instead.  You can tell your fuel is heavily oxidized when it turns darker and has a rancid odor and you can detect (anaerobic) microbial activity when you notice a sour gas smell (hydrogen sulfide). In my research for this answer I also came across a source that suggested that 2 cycle fuel started to seriously degrade after 30 days!!!! I will keep with the three months here but its something to consider in warmer climates if you have starting problems. 

There are two ways to completely solve this problem with minimal or no cost. For minimal cost you can add a gasoline stabilizer to your fuel mix IF the engine will be stored for anymore than a couple of months with fuel in. The better and cheaper answer is to simply drain the old fuel out of the tank ( you need to take the fuel valve off to let the tank drain completely) and by removing the fuel from the carb float bowl. 

We regularly see engines in the shop where they have been placed into storage for several years and the fuel has not been drained. The sour gas smell is absolutely disgusting.  Now this leads to a sensitive topic. Good seamanship. Leaving fuel in your outboard is a clear sign of poor seamanship. Going to sea with poor seamanship skills may eventually get you or your crew killed. And this gets us back to good and evil again. Bad fuel in a seagull is evil and YOU need to do something about it. There are millions of two cycle small engines out there and they ALL have the same problem with bad gas caused by poor owner maintenance. Its a billion dollar service problem and small engine shops have been making money from this since shortly after the two cycle engine was invented. And now the kitten is out of the sack or not to put too fine a point on it the cat is out of the bag! Its an incredibly simply and cheap fix. And its up to YOU. 

23. How Exactly do I ship a seagull so that UPS doesn't destroy it? 

You really need to build one of my Mk 10 shipping crates. They have never failed. You could toss the sucker off a truck and nothing would happen to the seagull cringing inside. The idea is to mount the engine on two resilient foam pads and tie the seagull down to the base with four strong ties. Once tied up its impossible for the seagull to accelerate within the box and make contact with a side - which is what causes the damage. We have shipped seagulls all over North America in this crate and have never had ANY damages.


24.Should I buy a new outboard or a used British Seagull? 

Lets start by saying that this is a VERY good question. Its not a particularly easy question to answer because it gets into opinions and emotions and history and reality and legends and fiction and fact. And other things too! It also depends on your intended use. And your resources. And interests.  There are a lot of variables. 

Lets see if we can help make the choice a bit clearer for you. If you are looking for a high speed outboard for a vessel with a planning hull then forget about a seagull. A seagull prop is geared down low and is designed to move a displacement hull. If you require more that about six horsepower for your vessel then forget about seagulls as most of them are 5.5 hp and less. For example the forty plus seagull a very popular model was approx 3 hp.  If you are looking for an outboard with excellent fuel efficiency then forget about a seagull. A seagull is a two stroke motor and uses older technology and any four stroke motor of modern technology will get much better fuel economy. 

Are you looking for a motor with an electric start? If so forget about a seagull as they all had pull cord starts. 

Are you looking for a motor with modern styling? If so forget about the seagull as its design hasn't changed much over the years and it has an old antique look to it. 

Are you looking for an engine that is quiet, vibration free and doesn't smoke much? Forget about a seagull! If you are looking for an outboard that will take straight gas then forget about the seagull as it takes a heavy oil-fuel mix -usually 1:10.

Are you looking for an engine with an enclosed flywheel? If so forget most seagulls as all the classics had rotating flywheels that would cheerfully spin at about 4000 rpm about three feet from your head!  

Are you looking for a new seagull? Sorry, seagull production stopped in 1996. New seagulls are no longer available.

At this point several of you will be shaking your heads and be saying "no thanks!" You really don't want a seagull. Bye Bye. What you really want is a brand new outboard with a warranty and all the bells and whistles. Yes it will cost you- but life is short and you really should treat yourself to a new outboard and enjoy it. It will be money well spent! Several manufacturers make excellent new outboards including Honda, Yamaha, Mercury, OMC and others, Now for the remaining bunch....

Do you like tinkering with outboards and doing your own servicing on a motor that can be easily serviced with simple tools?   Do you remember using a seagull as a child and having a huge amount of fun on the water? Consider a seagull - the fun is still there! Do you want a high thrust- low speed motor for your dinghy or small vessel?  Do you want to save at least 50%- and likely much more over the price of a new motor? Do you want a motor that will stand up in harsh marine conditions with only minimal maintenance and start when you need it?  Do you appreciate quality engineering and first rate materials?  Do you want an uncomplicated, dependable lightweight "get you home motor" when your main engine throws a rod or destroys its computer control module? Do you have a vessel with classic lines that a seagull would look "right" on ? Finally do you see an advantage in having a motor that can be completely submerged in fresh or salt water for a day or so and STILL WORK after you hose it off and replace the gas with fresh? A seagull is the ONLY outboard motor that will nearly always survive a serious dunking with no problems.  A well maintained seagull will likely outlast you!

So the best answer that I can give you after playing with these little birds for about 15 years is that - Maybe you should buy  a seagull or maybe you shouldn't. Its really up to your intended use and all those other factors. A british seagull can be a source of joy and  fun or a miserable, smelly, oily, little beast leaking gear oil or fuel mix all over your nice car or ruining those expensive yachting clothes or messing up something you don't want messed up!. They do seem to have a personality -hard working, dependable and tough. Very British. And they do seem to outlive their owners and sometimes several owners. And when you own one you are a member of a world class club (or perhaps secret society would be more accurate.) Get two seagull owners together, stories are traded and friendships develop fast. All over the world we have honest boaters enjoying their seagulls to this day. Its easy to remember good times on the water when your faithful companion is a British Seagull engine taking you to sea...and taking you back too!!. 

Its very likely that the British Seagull outboard will be with us for many decades into the future, possibly until the end of time.  In the year 3005 some future dude or dudette will discover one in a basement or archeological dig and wonder what happens when the funny looking cord is pulled. Boy will they be surprised when the sucker starts! 

A British Seagull engine is your time machine back to simpler times. Better times. Pleasant times. With one of these dependable outboards clamped on your stern ( OK on your vessel's stern!) they are happiest working- not hiding in a basement or shed. Spousal units love them too. I can't tell you how many times after hauling a seagull down a slippery beach that a grateful spousal unit will admit that she simply adores the family seagull as she no longer needs to row the dinghy five miles home from the fishing hole while hubby drinks beer. 

 25. Are there any books or manuals about British Seagull engines?

To read more about British Seagull engines you should first start with the operator handbook and service manual. The operator handbook provides information about how to mount, start, and operate your engine and it also offers in a concise and candid format some suggestions about good seamanship. The service manual offers a collection of service sheets on all the service operations you would do on a seagull. Things like assembly and disassembly, piston ring replacement, adjustment of carbs all in a concise format. If you are doing any sort of mechanical work on your seagull this is the one you want. 

Clymer publications has an out of print book on British Seagulls that you can sometimes find in the used book market. 

The best book on British Seagulls is the new book on them by Don Meyer publication  by Trafford publishing in Victoria, Canada. The Classic British Seagull is an excellent book which lets you in on the tricks of the trade learned by Don when he founded the British Seagull Shop and sold and serviced seagulls for an eight year period. Don is a blue water sailor and has sailed his 27 foot sloop to the South Pacific and back for a five year adventure. He took a British Seagull with him and so not only are you getting insight into seagull repairs you also learning that from the perspective of a honest sailor who has been there and done it!. There are many "gems" in the book and they will save you time and money and greatly increase your enjoyment of these engines. The book has now been published and is available from the author's website Madd Enterprises


26. My metal fuel valve on my gas tank is leaking gas!!! 

There are two types of fuel valves on British Seagull fuel tanks. One is metal and is rebuildable the other is plastic and is not. The metal type valve is solid brass and has a cork gasket in the "pull" There is a very small fixing screw which prevents the pull from being yanked out all the way. As time passes the cork gasket either dries out or wears out and then it leaks.  Leaking fuel is not a good thing. There are three easy fixes for this one. If the cork has simply dried out then you can try removing the pull and boiling it in hot water for about five minutes. That will cause the cork to swell up and the leak should stop. If the cork is worn out a quick fix is to take five wraps of plumbers teflon tape around the cork and put a small dap of grease on it. That should last until you can do a proper repair. Finally British Seagull produces a metal valve rebuild kit with a new cork gasket, fixing screw, washer and instructions. You can obtain them here. Its an easy repair and your fuel valve will be as good as new for another decade or two of use! People have tried to cut out a cork gasket from an old wine cork and they have tried other repairs but none of them work well. The cork rebuild kit is what you really need. A loose valve will not only leak but may also vibrate shut in use. Do yourself and the environment a big favor and replace the cork! 


FREE BUSINESS CARDS!  After using this service several times ourselves we are happy to refer it to you. Not only is it free - it also helps to support our site including all the free information and help with your seagull engines.  The printers also provide other services which are not free but this is their way of showing you what they can do for you. The cards make a nice gift too! Thanks!!!

Happy Seagulling!


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