Pro-X piston clearance

[Proformance1]

From a piston stand point, they are normally listed on the package or in the info avail with them. Normally if you go to a reputable shop they will know what it should be, especially if you buy them there. Never bore and hone to anything other than the size of the piston and the recomended clearance for stock or aftermarket application. In race, or competition, different story. If you want more info then you can start talking about finishes as well, lol

 

[Philip Clemmons]

Piston clearance is the difference in piston diameter relative to bore diameter. A 4.000" piston with .005" clearance would need a bore of 4.005"
This would be .0025" on each side. Pistons are measured 90 degrees from the wrist pin hole on the skirt, at the same level. They are a few thousands smaller at the top, and that's not where to measure.

 

[feartheride]

I shoot for .004 as long as the guy doing is not going to end up at .0035"
This being said I have noticed with the wiesco pistons after a 4 hr break in the pistons shrunk .0015" ,not sure if pro x do the same

 

[ridethelip]

Pro-x instructions
pwc-
jetski
2-stroke piston to wall clearance (they say this is general information and the original manufacture specs always supersede)

0,09mm-
0,12mm
or
0.0035”-
0.0050

I have used these and always tell the machine shop to go .004 and I have never had a problem.