FireHead Posted March 19, 2007 Report Share Posted March 19, 2007 I would say those pistons look pretty damn normal. You might putt around in some places or your low end is slightly rich or something but I don't see anything that would indicate a lean condition. No detonation but maybe the pic is not close enough. I would sure be checking tolerances about now, ring gap, bore taper, all things will tell you what is going on. I am thinking you might have a poor port chamfer causing excessive ring wear. The pistons skirts look fine. Mic things and let us know. I am just betting you have a huge number for the ring end gap. We see a bunch of engines with trashed rings at the exhaust because of poor porting and it grinds the ring thin in no time. look under the crown of the piston for color. tan brown is all and good, black or carbon build up is a sign of overheat and may indicate a lean condition. Brandon I may have made a couple misleading statements in this thread, now that I look at what I wrote again. The pistons look completely normal with the obvious exception of the malformed crown of one piston cause by the suspected lean condition. Since you haven't done any work to this engine before (I am assuming) it would probably good to fully measure and inspect your cylinders. There seems to be alot of ridiculously bad machine work that has been popping up around here lately (it's always out there it's just a matter of the frequency of it causing problem). Doing the inspection is a good way not to be a victim in this scenario. :thumbsup: Quote Link to comment Share on other sites More sharing options...
LiftdT4R Posted March 19, 2007 Author Report Share Posted March 19, 2007 Did you post pictures of your cylinder that I missed? If your cylinders look ok then maybe a new piston and rings will get your compression back up if the cylinder was machined correctly. :thumbsup: Nah, I guess I'll get some pictures of them today. I agree. However, the assumption you have to make is that the cylinders were machined correctly in the fisrt place. :thumbsup: I believe the cylinders are on their stock bore, I doubt that the previous owner ever rebuilt the top end, this thing was all stock when I got it. I would say your pistons look normal. Get them measured and if you can I would just say with the stock 64mm bore. What kind of Oil do you run in your Shee? josh Yamalube, 32:1 Quote Link to comment Share on other sites More sharing options...
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