Ah, was just curious if they gave you another piston, or if it had to be a certain size to be eligable for a new one and the rings together. Im really hoping its not the cylinder, but knowing my luck....well.... you know how it goes. Jmuddin...you mentioned piston wobble..do you think that may be the problem that Ive been having / hearing? Its just one of those out of the ordinary noises....not extremely loud, but enough to be annoying and make you think.... just curious if anyone else has had a similar experience?

 

I've had do it yourselfers just reinstall a std piston when they tore into em. They would bring em to me when they had a problem and I would give em the bad news! You don't just throw a std piston back in a worn 2-stroke cylinder! You always have to checked at bottom of cylinder against stock bore dimensions (the main place) along with varying points middle and top,almost always ovaled,egg shaped a bit. I've had to just go 1st over size piston and rings on some,2nd over on scored ones to clean bore up properly,all the way to 1mm over(where the cylinder sleeve is paper thin!(this is last bore,afterwards a new sleeve or cylinder is needed) After bore measurement,I would order the oversize piston and when I received it,I would measure bottom of piston skirt(they all vary a little,even Wiseco!) I would bore to PISTON SIZE and finish with my bar hone to .0015-.002 finish clearance between piston and cyl(measured when piston is in cylinder at the bottom. There are no short cuts on bore jobs if done right! Unlike a four stroke(atv engine or even cars to where you can sometimes just re ring em,if piston and cylinder is ok, 2-strokes are a completely different animal! They can produce a lot of power with less moving parts,but are harder on top ends,especially on race bikes than four stroke engines. Just a little give and take! I've typed enough. OPT

 

Well OPT....once again, a great deal of gratitude to you and all of your advise. It is much appreciated, and hopefully down the road there is something that I can advise to you. Thankfully Ive been a machinist all of my life and have a great contact that happens to be an automotive machinist and said he would "evaluate" the bore for me and let me know where we can go from there. Im just shocked that I missed something measuring that bore with Mittutoyo bore mics! Well, even the best of us screw up sometimes right? Build it up, and tear it down.....thats the way it goes. Ill keep you posted on my findings. Thanks again to all