I have a Suzuki lt250 that has a 1985 Honda CR500 motor installed. I bought the bike last year from a guy. Second day out I burned a big hole through the top of the piston. Anyway I rebuilt the motor and jetted it. It was running way lean. I took the cylinder off this winter to get it polished and the new piston still looks good. No signs of burning or pitting on the top of the piston. It is bored 80 over next time i have to resleeve. I want to know if I should run race gas straight, a race gas mix or what other options to make sure I dont burn a hole in the piston again. The compression is about 160 psi. It has been running great and no signs of wear on the piston but I dont want to go out this summer racing up sand mountain and blow it up again.
any comments would be greatly appreciated
also it has the stock lt250 radiator. Is this big enough to cool the 500?

 

Just run 91 and make sure the jetting is correct. What oil ratio are you running. 32:1 is a good mix

 

Im running AMSOIL which is like a 100:1 mixture but ive been using two bottles instead of 1 so its 50:1.

 

I have no experience with Amsoil, but 50:1 is about as lean as you want to run. I use maxima 927 at 32:1

 

the amsoil at 100:1 is supposed to be as good as the other oils at 32:1 but just to be safe I run 50:1

 

hey there camper from riverside, I haul hay for a living and have been to Westmorland, thats near brawley. they seem to sell the race gas everywhere. whats the octane in that stuff and is it safe to run in a stock bike Z400 and a shee

 

Its always safe, you really cant run too much octane and do damage.