Putting in a new weisco piston wr426


I've been reading everyones threads on cam replacement and top end work. Lot's of people getting ready for the summer as I am.

Has anyone installed the weisco piston on their wr-426? I'm changing the piston only as I bought the bike (2001) used and I'm not sure how hard it was abused. The valves have recently been adjusted last month. Is there a noticable difference with a weisco piston? I felt the change in my yz250, not sure if it will be the same with a 4 stroke...

When you are working on your engine, do you remove it from the frame? I'm still waiting on the Clymer manual before I start, but would like to tap your guy's experience for any tips before I begin.

Thanks in advance!

When you are working on your engine, do you remove it from the frame?

I haven't done anything major to my WR yet, but when I tore my XR down (more than once...), I always left it in the frame. The only time I pulled it was to clean the piston/valve/cylinder wall fragments from the tranny - hafta split the case for that. Sux sucking an intake valve thru the piston!

I have pulled jugs, replaced heads, done tappet adjustments (on the XR), put a new cam chain on, all while the motor was in the frame. You may have to pull a few other things out of the way, but I think it will generally beat pulling the motor. Again, this was on my XR. These Yami's may be different, and I may develop a different strategy.

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