all you two-stroke guys plz help

[wwclea01]

Ok I just rebuilt my 88 250r. I rode it about three time and noticed a loss in compression, so I tested it and it was 150, too low. I took the engine apart and the piston already has about .010 worth of wear. The cylinder is good except for the hone is wore off. I was told that it beeing bored wrong would have caused this too happen. Any other suggestions. I know no dirt or water was sucked in the engine, I had it jetted right, and I use good oil.

[ghak99]

If the machine shop bored it even the slightest too large, that could be the problem. I am guessing you used new rings when you had it worked over right?

[wwclea01]

yes everything was new. When I measure the cylinder it is smaller than .040 over the standard dimension. It has wore the heck out of my piston and rings, just three rides on the motor. I believe that the shop is going to be hearing it from me.

[hollywood43]

Did you give the shop your new piston along with the cylinder when they did the boring? If so, they messed up....

[rodenberg35]

well its a dumb question but did you put the piston in backwards. that would do bad things

[Bean]

honastly, that really isnt a dumb question, i have seen it happen, but anyway, did you install the rings upside down?, they are concaved and have to be installed the right way to seal the compression and let oil get on the walls of the clyinder

[miken]

Ya, I installed rings upside down before (hate to admit). It did show a lower compression with the ring upside down. Actually, it wouldn't do much more than idle.
Mike -

[Fuchs42]

Read the directions you tards. RTFM