97 Vmax 600XT twin cylinder piston failures

[3yamis]

Over Rev.

Well keep it oiled and run good gas to keep away detonation and make sure you don't over rev it and 20000 km is not a big deal.

I have Kimpex pistons in mine. When I smoked it I was a bit short on cash (Tax season and all) so that was all I could afford since the cylinder was $225, $75 for gaskets and odds and ends about all I could scrape together was another $120 for the piston set. Took 3 weeks to come up with that much extra money. Now I think I would go with the Yamaha ones but so far I can say the Kimpex pistons are just fine.

Yah the first time it failed I was in deep heavy snow and I had played around with my ramp wieghts; reving over 8000rpm= premature failure. This time with the wisco; it was not Rpm related; never been much over 8. Yah fuel could have been the issue by why the mag side again.