YZ 250 Fuel Recommend

[windsor427]

I have a 2001 YZ 250 previous owner told me he always ran C-12 with Yamalube 40 to 1. I have been running C-12 and 93 octane half & half with Motul 800 50 to 1. The bike runs great either way, but I am wondering if I should be running just pump gas?

Thanks for any input.

 

[Reesknight]

Unless the head has been modified, there is no gain in running race gas unless its just for octane consistancy, IMO. I'm sure someone(Rich) will correct me if I'm wrong. Of course if pump gas prices keep souring, race gas may just be cheaper! :bang:

 

[windsor427]

Thanks Rees, I was thinking of adding maybe just 25% c-12 next time just for detonation insurance. Then paying attention to any changes in jetting.

 

[dog2]

I have an older YZ 250 that I have been running pump gas for years. Like the last post said, unless the head has been modified for high compression, it won't hurt anything to run pump gas. Even if it has been modified, it will probably just ping a little bit under heavy load.

Just for fun, I tried running 50/50 with C-12 the last few months. IMO, the 50/50 runs a little cleaner, crisper throttle response, and starts a little easier, with NO pinging. The difference is slight, and could maybe be accomplished with jetting the pump gas, but it definately runs a little better.

By the way, the pump gas vs. race gas issue has been debated here many, many times. The best advice is to try it for yourself and see what you think. You will not damage anything running pump gas.