I suspect it has more to do with the set-up than the piston.

Exactly. And they take a whole lot of careful setup to work, which is my point. I just want the guy who is asking about these pistons to know what he is getting into.

Be prepared to do this:

They needed huge clearance and required very careful warming and running in. You'd have to heat cycle them and then pull 'em out and rub down the high spots. Then run them up and down the road for a while, then pull it apart again and rub down any more high spots. Then you go racing.

Then, loose horsepower because you large clearance required makes your ring gap larger.

The guy I got my info from did some extensive testing on the Wiseco's. Heat cycling them and checking them with a micrometer to see how much they changed. The Wiseco's consistanty changed way more than any other piston he has tried. He runs a machine shop here locally and does TONS of standard bore and overbore kits, and alot of testing for a local Jetski pro.

I WISH the Wiseco's were better. I dumped a whole lot of money into my bigbore kit and wished she had turned out rock-solid reliable. In the end, I wished I would have just got the Tyga 300 kit.

Just be prepared: every Wiseco that I have seen seized in an NSR cylinder has also cracked the exhaust port and ruined the cylinder. It'll cost you alot more than just a new piston kit and replate.
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Paul Herr
'88 FZR4/GSXR/YZF Frankenbike
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