stuart turner P66

J

jeremy_king

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Sorry - I'm new and might have done this incorrectly.
I have just purchased an old boat, with an even older motor in it. It a Stuart Turner P66 on the plate it has marked # 22 B 856 then under that 10 and 1 650.
OK, I thought it was seized. However I have managed to “free” the flywheel.
After reading fairways website I think it may have been dropped on the flywheel, or similar, as it has flywheel rotation from 12 o’clock to 10 o’clock (clockwise) then gradually “grips” or can’t rotate any further.
Is this symptom consistent with a bent crankshaft tail?
It’s my first 2 stroke inboard – dad had a blaxland though
If I’m in the ball park can somebody please let me know?
I'm in Australia ... so can't go down to Fairways at ease.
Thanks
JK
 
Sounds pretty obvious, but have you taken the plugs out? Maybe you've got an ST with decent compression (most unlikely).

I don't know the P66, but the ST's are built like the proverbial brick outhouse (dunny to you). Yes, you could have a bent crank from dropping it, but it's equally likely to be rust in the cylinder bores.
Try pouring some light oil or diesel into the cylinders and "work" the flywheel back and forward and see if it frees.
 
Thanks for that. I've had the plugs out and had 2 screwdrivers resting on the piston heads and turned the fw to see them bobbing up and down. Maybe there is rust where the inlet or outlet port is?? I'm now waiving on the crank theory only due to the fact that the prop shaft still rotates perfectly at the coupling. I took the sideplate off on the head and a whole heap of oily goop came out ... maybe that's something not quite right? ... I'll diesel up the pistons and see what happens. Yep and it is built like a brick shizenhousen only not as useful at this juncture.!
Again, thanks for the hlep
 
[ QUOTE ]
I took the sideplate off on the head and a whole heap of oily goop came out ... maybe that's something not quite right? ...

[/ QUOTE ]

Hey, interesting! Could the engine have been filled with oil before being mothballed? Check the crankcase isn't full of oily gloop.
 
the crankshaft is made up on various parts bolted together, (i cant remember the tech names) these could have "slipped" causing the crank to lock-up due to misalignment.
i had one of these engines as my first inboard /forums/images/graemlins/mad.gif
 
I'm not familiar with the ST P66, but I do have an owners workshop manual for the P5 & P55 models. This has exploded diagrams and instructions on rebuilding crankshaft assemblies. I could photo copy and post if it's of help.
I think the cover plate you refer to is to give access to the water jacket only, it will not get you access to the working parts.
Dan
 
If the crankshaft is bent it will be at the flywheel and not internally .

cheers

terry
 
I agree with Clyst - the cranks on these tended to break (in front of the Lymington Frightlink ferry) - rather than bend.

ST always said not to rest the weight of the engine on the flywheel. I would expect if that is the problem the flywheel would not be running true - though of course you cant know that yet as it doesnt turn! The output shaft is not part of the crankshaft so the fact that turns freely only means the gearbox is free to turn.

I would agree that it is far more likely that there is rust in the bores stopping it turning. Plugs out and a cup of diesel oil to free it all off, then keep going. Get a socket to fit the flywheel nut, and use a decent T bar with a piece of waterpipe for an extension to move it. There is insufficient leverage at the flywheel - even if you can get a proper grip on it to apply much of a swing to it.
 
Hi Dan,
Thanks I have a P5/55 and 66 manual. People I don't know just keep giving me information and telling me bits and pieces on these old motors. One guy photocopied both manuals and dropped them into my office. Fab! Thanks for the information on the water jacket and the offer on the manual.
Cheers
Jeremy
 
Cheers Terry, I read the fairways web to mean if it's rested without block under the motor (on the flywheel and shaft) the shaft would go first?
Anyway the flywheel spins true so I'm leaning back toward rust.
Thanks
Jeremy
 
Hi,
I'm going to diesel the bores ASAP.
The motor / flywheel does turn, but not a full rotation only 5/6ths of the way, then it jambs (is that the right spelling?).
I'll then find the socket and bar as you suggest and use brute force. ... Woohoo!
Cheers and thanks for the help.
Jeremy
 
if you are in australia we know that merricks auto and marine know these engines very well
they are in north Vict
talk to micheal hodgson tel 03-59897257
 
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