Roys second 102 series build

[african imp]

The first one was done from a box of parts that was gifted to me by a friend who sold his Yamaha outboard agency out, he had done work on British Seagulls as and when they came into his workshops.

As I have now managed to open the second 102 power block he gave me, it was very stiff and a difficult job to open, I can now think of making it into an outboard engine again?


A quick look of possible parts shows me what is on the bench, the gearbox and the connection tubes should be correct, I doubt the propeller and shafts are ?

[african imp]

The motor has been opened and found to be in really good condition, so much so its close to being new, why it was seized I have no idea, there is no evidence of water, it was the second piston ring I think?

That stainless steel rod and plywood scrap was the push rod that I used with a large G clmp to press the seized piston out of the bore and via the spark plug hole, the idea worked rather well.

[african imp]

[quote="african imp"]The motor has been opened and found to be in really good condition, so much so its close to being new, why it was seized I have no idea, there is no evidence of water, it was the second piston ring I think?

The piston once removed was soaked in an oxalic acid solution overnight, I have now freed off the second ring, the first ring is still firmly in its groove but given time I think it will free up.

[african imp]

My parts bin may not have the right sized gear box for a 102 motor?

Can I fit a smaller sized gearbox, I may have to use the smaller Viliers carb as well?

I wll have the motor and down tubes, there is no shaft to the clutch, my prop may be too small?

Lots of questions.

[african imp]

The motor I am using had a seized piston, it was some calcium type stuff under the top ring.

When the block was removed from the crank case I found some strips of red silicone material.

If they were from the crank case joint, a factory build, I have an idea that this motor has run very few hours as the silicone would have been blown out the exhaust a long while back otherwise ?

I will open the crankcase and reseal it just in case of a leak?

[african imp]

The only complete gear box that I have may be too small for a 102 series engine?

[fleetingcontact]

A 102 coupled to a featherweight gearbox is probably the most common 'racing' Seagull out there. What you have there appears to be a 12:30 reduction sealed box as fitted to Silver Centurys and later Fortys. The only issues are making a good seal between the box and the pump housing and (naturally) lining up the driveshaft. Apart from that its all good. Suggestion: make your own gasket from aluminium and seal with goop.

[african imp]

A 102 coupled to a featherweight gearbox is probably the most common 'racing' Seagull out there. What you have there appears to be a 12:30 reduction sealed box as fitted to Silver Centurys and later Fortys. The only issues are making a good seal between the box and the pump housing and (naturally) lining up the driveshaft. Apart from that its all good. Suggestion: make your own gasket from aluminium and seal with goop.

Thanks on the advice, I have now test assembled what may work, the parts seem to fit?

The flywheel is a spare.

I do not have the correct round fuel tank, Is there any info on fitting the later rectangular fuel tank to the 102 motor?

[fleetingcontact]

Look at Seagull101's ED 102 in the for sale section (Jacob, can you post a higher resolution pic please). To my (limited) knowledge this was the only 102 which featured a square tank. The model was probably not that common and the chance of finding some mounts are, I presume, slim.

So you either find the more common earlier types or get busy in the workshop - can't be that hard...principal tools for the job - angle grinder, drill, blowtorch, BFH.

[Hugz]

Yes... rectangular strip of iron with 90 degree twist and three holes. You could use an oval tank using same principle!

[african imp]

Look at Seagull101's ED 102 in the for sale section (Jacob, can you post a higher resolution pic please). To my (limited) knowledge this was the only 102 which featured a square tank. The model was probably not that common and the chance of finding some mounts are, I presume, slim.

So you either find the more common earlier types or get busy in the workshop - can't be that hard...principal tools for the job - angle grinder, drill, blowtorch, BFH.

Thank you.

[african imp]

Yes... rectangular strip of iron with 90 degree twist and three holes. You could use an oval tank using same principle!

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Thanks, I see the twisted flat iorn and I have some in stock some place.

[african imp]

A digital meter on the Wipac coil that I did in January said I had 4.9 ohms, in practice would I see a decent spark though?

I have just run the power head up with an electric drill and a flexible joint, the spark from the NGK plug is fine


If you look closely you can just see the spark.


I am now thinking that if I had a carburetor and petrol tank on this assembly the old seized motor would run again once more?

[african imp]

I am pirating items from other motors I have to enable me to test this 102 motor out, one item is the oval HT cap retaining plate.

[african imp]

As a one time boat builder I have used epoxy glues and pastes for many years, the epoxy is in many ways a welding tool, wood to wood, wood to metal and metal to metal as well.

The only Seagull control arm I had was bent, I straightend it out and it then broke, its now bonded with an epoxy paste, when that has cured I will wrap the repair with glass cloth and a thin epoxy mix.


The 102 engine flywheel had some dings in it, I have given it a basic clean up and filled the dings with epoxy paste.


The items are out in the Sun which will speed the cure time up by some hours.