Head Gasket

[2-Stroke Tom]

I did the head gasket on my 500 this weekend and everything went well, and it was easy to start thanks to Larry's compression release modification. When I took the new head gasket out of the package and compared it to my old one, it was obvious my new one was thinner. The old head gasket measured 0.4mm thick, and the new gasket (11004-1187) measures 0.2mm. I adjusted the new carburetor and drove it around my block, and it seemed to run awesome! My question is, do you guys think I may run into detonation problems due to the higher compression? I always loved not having to run race fuel, so if I do I will go back to the 0.2mm head gasket (11004-1209).

I had to get the job done because as soon as I come back from vacation at the end of this week, I'm packing up and heading out to the desert for some riding. If you guys think it may be an issue I can always grab a few gallons of race fuel for next weekend's ride.

I torqued the head in an incremental a star pattern, doing the KIPS bolts last. Sprayed the head gasket with Permatex Copper for added insurance. Here are a few shots.

[cmotodad]

What year came with the thinner head gasket? What does it do to help the power on a bike that had a thicker one? Thanks

[Motorrad]

What cc did Larry cut the head to?

[2-Stroke Tom]

What cc did Larry cut the head to?

Ahh, good question Motorrad. Since I've never touched this motor, I never requested any specifics from Larry. I've just seen him recommend the thinner head gasket on the later 500 motors. I guess either way, I can easily change it.

[Larry Wiechman]

Stock head with .010 clean up cut on gasket surface.

[cmotodad]

Sorry, is there a thread that defines what head gasket fits what year? Also, does the compression increase change the low end much and how does it efffect the top end? Thanks.