My profile shows whats on my bike....the last mod was the GYT-R High Comp piston and top end gasket (installed by a reputable local Yami dealer). Two hours later, I cracked a cylinder at about 5K r.p.m. Of course it tore everything else up and the top end was a total loss. Yamaha Corp. agreed to replace everything for me at no charge (including a new High Comp piston). They also told me that I HAD to use racing fuel from now on, or their service would not be warranted. I opted for VP's Ultimate 4 on the fuel...it is well known to be one of the best but is very expensive ($9 / gal.). The new fuel burns cleaner and cooler but is this high cost fuel really necessary with the mods I've done?? Any thoughts?!?

 

Did you orginally have a GYT-R HIGH-COMP PISTON in your quad before the cyclinder cracked?

 

Depends on just how high the compression really is, but yeah, you might have to run the race gas.

 

No....the prob occurred after the install of the high comp piston. Its any body's guess exactly what went wrong but I was talking with someone yesterday (Sunday 05/08/05) and he had heard of similar occurences when that mod has been done.

 

Dont take a chance run the race gas. You could put regular in and see how it runs, but i think if you have higher compression than before it will buck lot and not run smooth.