Piston Related Question

Jun 4, 2006
82
0
With the 1982 YZ490J and .040 over wiseco piston how much will the bore need to be for everything to work right within clearances? i'm not sure of the clearances and stuff.

i only have the stock specs for the regular 87mm bore in my clymer repair manual

do i just get the bore made to 88mm and order the .040 piston kit.

or does the bore have to be a little different to match with the piston and rings specs.

would appreciate some xpert advice because the machinest who i am going to get to bore my cylinder sleeve needs to know the technical stuff so that the wiseco piston fits proper within the specifications and stuff...
 

Chili

Lifetime Sponsor - Photog Moderator
Apr 9, 2002
8,062
17
I always just order the piston and take it with the jug to our mechanic/machinist. He makes it work from there.
 
Jun 4, 2006
82
0
Ya i'll just order the wiseco .040 piston kit and when it arrives bring teh jug and kit down to em.

he should beable to make it work from there
 

Sgt.Will

Member
Sep 21, 2006
10
0
dunno but maybe u should get it 1 over