93 501 piston sizes

gday Reed

each letter is a 0.01mm increase in piston diameter

if you go to service manuals on left hand side of main page and download 2004-2008 repair manual it gives a spec for the different 100mm pistons, should be the same % of bore diam

the wossner site is really good, lots of info on sizes and clearance of each piston. and they list 501 pistons.

as a rule just keep it simple

A = new liner
C = used

regards

Taffy

no worried Reed

FWIW I always measure the liner first, if you don't have a bore gauge then a feeler gauge in the bore beside the lower skirt of a piston then measure the piston with verniers has good accuracy and also be aware different piston alloys and coatings require different clearances.

99mm with cast iron sleeve....... didn't make 20 hrs.......

KTMTalk.com


ie my elko was right at size I or A in a new alloy liner and a II or B for a worn liner (0.04mm minimum clear) but for the proX piston alloy and uncoated piston even in my worn liner i needed an ProX size A (0.07mm clear ideal minimum) even the A was still a bit tight

that is for the same bore diam; depending on piston characteristics; there can easily be more than a 0.03mm difference in max piston diameters which is the difference between A and C

if in doubt heat the piston and liner to 400 - 450F and see if the piston still drops through it