California Premium Gasoline

Does anyone know why I can no longer get 92 octane premium here in CA? All the stations I've been in in the last two weeks have changed their pumps to 91 octane. Nobody seems to know why. I've read that race fuel is not good for the yz carb gaskets, although I know many people on this chat use race fuel. I'm concerned that the 91 octane will knock and damage the engine over time. What is a good substitue without going for race fuel? Maybe a mix of avgas and pump gas?



Stay away from the Avgas as it is made for fixed throttle operation. Dirtbike riding is anything but fixed throttle!! You can mix pump gas and race fuel 50/50 or even 3 gals pump with one gal race fuel. That will get you octane high enough to satisfy these engines.

I have owned YZF's since they first came out at the end of 97. I have used straight race gas in these bikes without any carb problems. I like the consistency associated with the racing fuels. You can buy pump gas one time and it will be 91 octane and the next time it will be 90.4 octane. Especially here in California, pump gas contains so many additives and anti smog agents that I worry it will not be what the engine needs.

Hope this helps you out, Ernie

I agree with the fuel recommendation, the only way I could get consistent (and good) plug readings was to mix pump and race fuel to run a 100 octane mix and it runs great!

Thanks for your imput YZ & Tom,

I'm cheap, but I guess I'll have to opt for the race mix in the future.


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