TRX250R.ORG
Workshop => Engine and Bottom End => Topic started by: JOEY11 on June 11, 2022, 12:47:33 PM
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I got my 87 engine and took the covers off just to check it out and it’s definitely a nice engine. All the case threads feel tight and new like it hasn’t been abused it’s whole life. I was looking through the intake and noticed a piece of rubber or something on the crank. I pulled the cylinder off and found these little pieces of something only between the rod and crank weights in the pic. Any idea what it could be? It looks like pieces of permatex. The seller said it’s a fresh build and it definitely looks like it. I’m going to do a leak down first and hopefully it’s seals like he thought it needed.
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The engine has had broke piston pieces hitting the connecting rod where there are silver spots covering the copper plating. The little pieces are probably "piston crumbs" from the broken skirt or from a hole that was burned through the piston crown from not using good gas or overly advanced ignition timing.
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That’s not good. I carefully removed some of the pieces and it’s not hard so I didn’t even think it could be that. It feels rubbery but Im sure you’ve seen it a hundred times and know what it is.
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I looked at the pieces again and they’re rubber. The seller said he was told it needed main seals due to burning crankcase oil. The seal looks installed flush so I’m not sure why it would be sucking oil. I attached pics of the piston and cylinder and I think it looks ok but I’m no expert and plan on doing a leak down and seeing for sure if that’s the issue. He’s got 1 piece of the trx gasket and says the head is shaved so I’ll do a compression test also. I bought a compression tester and tested the engine in my trike and it’s was 200lbs tested 3 times and that’s after 1.5yrs of running 93 pump gas with 927 the whole time always from the same shell station and same exact pump. I bought some Torco110 to start mixing with 93 for this new engine but I might run it in the current one. I can’t believe after riding every weekend for almost 2yrs the top end is still strong.
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Here's some pics
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The piston looks terrible. You the skirts are trashed. The top shows detonation. I think you have more than one thing wrong and is not something I can easily help you with on line. You need some professional help with your whole package as well as someone that is willing to take you under their wing and help educate you on basics of tuning and caring/maintaining your bike.
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Like Mr Hall stated that piston is beyond usable. I would suspect that it is much smaller than the cylinder bore. Definitely needs bored and a new piston.
Loren
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I guess everyone starts somewhere and why these forums are here to help the inexperienced learn. I had a feeling the piston didn’t look good by reading other posts showing pics especially since the seller said it only had 10mins of run time on this piston and I think I knew better but didn’t want to admit it. I’m in NJ and don’t know of anyone that can teach me about this so I’ll have to send it out to be corrected. Luckily somehow my running engine is still going so I have time to fix this one without needing to rush getting it back together.