A Piston Question

[Bob]

Will a piston designed for a 77-82 KTM 175 work in a '72 ?

Will a piston designed for a 77-82 KTM 250 (71mm x 62mm) work in a '76 ?

Thanks,
Bob

[Mike Lenz]

175-no,but I think a 77 on piston,and cyl might work together on a 72 lower end.Stroke is the same. 250-yes should work ok. Some later 250 pistons have a corner on each side of the back of the skirt that need ground down,but I have raced with them and work fine.