Stuart Turner

[macnorton]

I am looking at a 10hp twin cylinder one of these which has lost compression, I removed the head and the gasket fitted is a re-enforced fiber one but it does not have any compression rings around the cylinder.
Is this usual for this engine? and could I use a copper one instead?
I would like to try a new gasket before I remove the engine and strip it, but am i wasting my time?

Anyone know the answer to that one?
Thanks in advance for advice...

 

[KristiferColumbus]

I am looking at a 10hp twin cylinder one of these which has lost compression, I removed the head and the gasket fitted is a re-enforced fiber one but it does not have any compression rings around the cylinder.
Is this usual for this engine? and could I use a copper one instead?
I would like to try a new gasket before I remove the engine and strip it, but am i wasting my time?

Anyone know the answer to that one?
Thanks in advance for advice...

I had one about twenty years ago that seemed brand new (I found out that it had been stored with the Admiralty since about 1942 I think it was so it was infact brand new).Still a ******* & I would'nt touch another one with a barge pole.
Get yourself a good outboard that would be my advice.

 

[Tranona]

From memory the head gasket on my P55ME was copper. The only difference between the 8hp and 10hp was that the latter had aluminium pistons rather than cast iron and revved to 1650 rather than 1500.

Poor compression is just as likely to be worn rings or worn crankshaft seals. I think a company called Marlex Marine has taken over from Fairways, although the latter still has a website showing on Google.

 

[miket]

Marlex

Correct.
Martin Steggles, who is very knowledgeable on all things "classic boat" bought the stock from Fairways.
If you find you have major problems I just happen to have a 2 cylinder ST in my garage c/w gearbox, as lifted out of a sailing club rescue boat. Only replaced as youths couldn't handle it. Replace d by Japanese. I think it is 55. Would be pleased to see the space in my garage!!

 

[Dipper]

Slight thread drift but I have 14 assorted paper gaskets for a P55ME which I am happy to post free to a UK address. I believe it comprises a complete set which was in an envelope with the code 13677 plus a few odds and sods (some duplicates).

First to PM me gets them!

Edit - Gaskets no longer available.

 

[macnorton]

Correct.
Martin Steggles, who is very knowledgeable on all things "classic boat" bought the stock from Fairways.
If you find you have major problems I just happen to have a 2 cylinder ST in my garage c/w gearbox, as lifted out of a sailing club rescue boat. Only replaced as youths couldn't handle it. Replace d by Japanese. I think it is 55. Would be pleased to see the space in my garage!!

PM sent

 

[miket]

PM replied

.....

 

[oldharry]

A quick test we used to do from my motorcycling days was to pour some engine oil into the cylinder (head off). If one cylinder drained down quicker then we knew there were ring troubles and needed to go further in. As always, not a conclusive test, but a good pointer.

 

[macnorton]

A quick test we used to do from my motorcycling days was to pour some engine oil into the cylinder (head off). If one cylinder drained down quicker then we knew there were ring troubles and needed to go further in. As always, not a conclusive test, but a good pointer.

No differerence in compression when oil was added so not rings, but thanks for the idea anyway

 

[oldharry]

No - thats not what I meant. If the head is already off, set the pistons so they are about half way up the bores, but not near any ports. Pour about half inch of oil into each pot, and leave it for 5 minutes. If there are ring problems the oil will usually have drained away. If the rings are good, the oil will stay put. Saves unecessary dismantling.

 

[Blueboatman]

Having sailed with one of these ( we did a lot of sailing and a bit less, er, motoring..)

Firstly you did well to get the head off without b@ggering the studs-often these have corroded into place..

Secondly, has it been stored sitting on its flywheel instead of up on blocks ? The crankshaft seals, IIRC, tend to flatten and thus require replacing if loaded in this incorrect manner in storage..

Thirdly, if you like it and fix it, consider replacing the magneto internals with a simple set of points linked to a regular car coil and 12v battery-much much more reliable although by now I would imagine that simple electronic ignition is available as a retrofit as well...

Lastly, decoke the exhaust if you are goin g to overhaul the lump-they are sensitive to excessive back pressure, again IIRC.

 

[AndrewF]

There is a large font of information at the following Stuart Turner group. http://groups.yahoo.com/group/stinfoexchange/

 

[macnorton]

No - thats not what I meant. If the head is already off, set the pistons so they are about half way up the bores, but not near any ports. Pour about half inch of oil into each pot, and leave it for 5 minutes. If there are ring problems the oil will usually have drained away. If the rings are good, the oil will stay put. Saves unecessary dismantling.

I did that after I removed the head, and the oil remained for 10mins so not a ring problem.

Blueboatman: the engine is fitted in a boat and has points/coils as well as an alternator conversion already fitted.
Also the boat is not mine Im just trying to help out a fellow club member.

Thanks again for all the input...

 

[Latestarter1]

Having been brought up on this motor on the Thames before making the transition to Doxford I will never knock it unlike others here.

You will need to delve deeper into the engine I am afraid. The phosphor bronze crank case seals have gone. As you try and build compression on one side of the crankcase it is just passing to the other half of the crank case a visa versa. Split the case fit new phosphor bronze seals and engine will start like a little trooper.

I expect motor has stood for a while. A P55ME with coil ignition running on unleaded fuel is a sweet little motor