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Y 140 no compression

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Old 05-07-2012, 08:04 AM
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pacoflyer
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Default Y 140 no compression

Gentlemen,
I tried to start my trusty 140 over the weekend after it had been stored for about a year in ultra oil. The engine ran but with low power,lots of smoke and no compression. Even after it heated up we had little compression. The valves look fine, free and moving so I suspect I have a stuck ring. Is there a way to free it up without dissasembly ?

Thanks in advance,
paul
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Old 05-08-2012, 09:41 AM
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Default RE: Y 140 no compression

What do you mean by it being stored in ultra oil? actually submerged? If it was totally submerged and flooded with something I would not suspect a stuck ring, not ruling it out just not my first suspect.
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Old 05-08-2012, 01:55 PM
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Default RE: Y 140 no compression

Thanks for your response
Submerged ?? no.
As with all my engines, I put a small amount of oil in both the glow plug hole and in the carb and turn the crank a couple of times to distribute the oil throughout.
Ultra oil is a storage oil specially made for YS engines
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Old 05-11-2012, 07:35 AM
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Default RE: Y 140 no compression

That makes sense, the "stored in ultra oil" sound like it was submerged and I have run into a couple guys who have stored engines that way (I don't question it I just nod).

Low power and low compression with a lots of smoke either a stuck ring or an intake valve that is not sealing 100%. The problem in trying to figure out which is that both paths lead to the crankcase and ultimately the carb. In either event you need to pull the head to look at the valve seat or to pull the piston. I don't know of a way to free a stuck ring other than to pull the piston and clean the ring groove. I'd pull the head first and check the valves for sealing and then if they are sealing properly go ahead and pull the back plate off and remove the piston since you are already half way there.
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Old 05-12-2012, 04:53 AM
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Default RE: Y 140 no compression

Thanks Guys for all your replies.

Finally got this puppy apart and the valves looked fine..pretty clean and seating fine. Took some compound and cleaned them up anyway just to be sure. Lifted up the sleeve to expose the ring..it was very clean and moving freely. Popped the wrist pin and out came the piston and again all looks OK.. Now Im really confused as the engine ran like crap. One other minor detail though. When I removed the head I noticed that there wasn't a head gasket in place. Whoever had this engine before me must have tore it down and not replaced it. I'm pretty much sure this was the problem..I'm hoping anyway.
Thanks again for all your suggestions,
paul
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Old 05-13-2012, 04:52 AM
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Default RE: Y 140 no compression

Change the ring too...
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Old 05-13-2012, 05:20 AM
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Default RE: Y 140 no compression

The head gasket is aluminum and may be stuck to the head. But do change the ring while you are in there just to safe.
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