i run premium but have friends that run av gas and race fuel. my bike is almost stock and i have never had any problems. why spend the extra money?

stock bike doesnt need race fuel. run 91 pump gas. unless you like pissing your money away.

Don't ever run AvGas. There are additives in AVGas that although work in jet motors, don't work well in quads/rails/rhino/jet skis etc. I might get flamed but I've seen it first hand. Pistons exploding, cranks letting go. Most people run AvGas because it's cheaper that VP, Elf, Trick any good race fuel, and they are trying to get the performance without paying the price. Plus it's been said, stock bikes run fine on premium.

No need for race gas unless you have motor work and the bike was tuned for it.... Stay with the 91...

X2.... Bike builder showed us some of the problems with Avgas... Although a buddy has used it in his 88 banshee and is only on his second rebuild and the rebuild was just to keep up with the 4-strokers....

As far as Av goes I know people who have used it and have had no problems.
I spoke with a guy who was a engineer at a refinery once and asked him about it . His story was Av Gas's Octane Rating is not computed the same as Reg Gas so AV is not the listed octane the way us land lovers calculate it said it was about 97 or so. Ever Notice the sticker on the pump O= M/R2 or something along thoose lines AV is differant in the way it is calculated. He said that AV was designed for more of a constent RPM and compaired it to Diesel in the way it is designed to burn. He used alot of big words that I don't remember but in the end said he would use it, Just don't think your putting in the octane your thinking your putting in, Also said it was a very DRY fuel and would either add a little 2 stroke oil to 4 strokes or run it in 2 strokes only.

And Tanman isn't Jet fuel differant from Av Gas ????

A lot of people think that their bike will run stronger/faster with race gas but its not true. It just keeps engines with higher compression from pinging. Glamis is about the most harsh environment you can run an engine. I had a stock CR500 that would ping with 91. Switched to 50/50 race mix/pump gas and the ping went away.

Yes, and no. I didn't mean as to 757 jets but AvGas is avaition fuel, for smaller type Cessna planes. I should have said planes instead of jets. I stand by my words. I've raced all kind of smaller stuff, as listed jet skis, mx, I've seen the motor carnage AvGas did. The people that used AvGas did it for the reason I listed, trying to get cheap performance for what you said the octane rating. I wouldn't ever use it. I was actually sponsorede by an east coast place when I lived there, Power Mist, but when I stopped racing and needed high octane leaded fuel I then bought VP. To each his own, I just threw it out there for a warning. Like the commercial goes, you can pay now or you can pay later.

its kind of tricky ehall. the quick answer is YES a stock bike will make more power with a race fuel like U4.2.

race fuel is not always about higher octane...U4.2 makes more power because its oxygenated. now when it comes to glamis its a little different than riding hard pack. its true that higher octane is needed for high compression motors. but....glamis puts such a load on the engine that some bikes require higher octane even though theyre not a high compression motor.

as a side note my yz250 manual recommends 95 MON.....just guessing but that would be around 97-98 octane from a gas station pump.

i only run 91 at the track...but at glamis my bike wont pull 4th gear up steep hills unless i mix in some race gas. i personally LOVE THE STUFF!!! smells good too

AVGAS is not used in a jet engine. It is a form of gasoline, not kerosene or JET fuel.

The big deal with AVGAS is it does not have the added cooling properties that race gas has. As mentioned, it is drier and you will run hotter and burn up your engine.

I run 91 in all my bikes and works great. Higher octane is onlly needed if you run higher compression. Higher octane gas also makes it harder to start...hope you have an "E" button.

Lastly...I have met very few people that actually can make use of a high dollar, high compression motor in a bike or quad...that needs race fuel to keep from pinging. If you are that good...then you already know why you need race gas and shouldn't be asking these questions. Save your money and spend it on suspension, riding gear, a toy hauler...new truck...you get the point.

i ran ll100 av gas in my 2 strokes for years. never had any issues since i was mixing oil into the gas anyways. for me it wasnt a cost issue, it was just easier and quicker for me to get the av gas. if you need a little higher octane than what you can get outa the pump but dont need as high as race gas it works. you may have to rejett the bike though for it. thats probably why people have issues with av gas they dont check the jetting.

my last cr250 i had i had to run race gas. on anyhting else it detonated (pinged) bad and puked coolant everywhere.

I've been racing motorcycles for 25+ years and have never seen or heard of Avgas causing a bike to blow up.. I do agree, race fuel is a waste on the modern four strokes, they need 91 oct and thats it.. Although when I race long distance Desert stuff, I mix 50/50 with VP C12. Only because these bikes get so hot and are on the raged edge I feel safer running it.