Has been my experience that similar jap engines do have around .002 inch piston clearance when new and around .010 inch ring gap. How much taper is in a new oem piston? ie measurement at the skirt vs below the ring lands. Would also be good to know whether the stock piston is forged or hyperutectic (spelling?) cast and the silicon content. The forged pistons they sell over here have a lot of taper and still require more generous clearances compared to a good hyperutectic cast piston from Japan. They have less silicon and expand more. Took a nasty high speed header on a 500 M-Star (with a forged piston) when I tried to set it tighter as you would a Honda and it seized. The service manual I have for my 03 shows max. ring end gap as .023 inch as a wear limit. Shows a minimum piston skirt diameter as 94.88MM. Doesn't give a cylinder measurement, but assuming is actual 95MM, that would allow a max clearance of almost .005 inch. Those figures seem in line if used as a wear limit, but not new specs.
dan
PS your right, I meant to say ATDC. Nothing like confusing everyone a bit and seeing whos awake
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