has anyone used av gas in there quad instead of race fuel?  thanks for any advice

I have always heard that AV gas is "missing" something that makes it not as good a choice for performance engines. Now if I could just remember what that something was my post here might be more usefull.

Now I am in no way some sort of petroleum expert. But you need to make sure that you are talking about Aviation Fuel and not Jet Fuel. Jet fuel is very similar to diesel and will not work in a spark fired engine.

As you have said AVGas I realize that you probably are aware of this but anybody else who might read this and get a wild hair should not put Jet Fuel in anything with a spark plug.

there are different kinds of av gas, some are high or very high oxygenated which will be bad for your engine, it will run very lean.

these fuels are just not made for typical gas engines. You will burn up or at least partly ruin your motor.

its better than running pump gas, but just barely.  use racefuel if you are even questioning it.  the price difference is minimal compared to a motor rebuild...

AV gas or Aviation Gas is not rated on the same Octane scale as the 110 race gas you are compairing to.  Av gas is usually less than 86 octane and is made to burn at high altitude and alot colder temps than we see usually.  so there for it should not be used in race motors!!!!!!   91-93 Octane Super Unleaded will usually be fine in an engine with less than 12.8 compression ratio as long as you are jetted right and it is not 120 degrees out side.   But their are always exceptions to the normal.  The most of our motors with say 13.5 need about 101 octane to get buy.  Some people same money and cut or mix race fuel with super unleaded to get 97-105 all you needed is to keep our motor from  pinging or preignighting any more octane than that is just wasted and will not help performance.    

Just My 2 Cents Worth

     Glenn Hess

thanks everyone Im going to stay clear of the Aviation Gas

Glenn would the 110 race fuel be alittle much for my stock yfz after further research I was thinking of backing off to the 105 and not trying to cut it with pump gas

what do ya think?

and as allways thanks to helping out the new guy:)

I have ran both Sunnoco 110 mixed 50/50 with Super Unleaded and just Super Unleaded in our YFZ and didn't see any real difference. And I did that over a three year period with the same motor. Curently the motor has a WR crank in it so the compression will be  a Iittle higher so I will probably go back to the 50/50 mix, that is if I ever run it again. I am not sure that there is anything to be gained by running the race fuel, even 105, in the stock motor. Plus I think the YFZ after 05 had a little less compression anyway.

 I will say that when running with the race fuel our packing in our silencer doesn't seem to last as long, not sure it thats really realated but it seems to be.

Why the 105? The motor was built to run on 91 and 93 would be perfect for racing. These guys are trying to get you to not burn your valves and top of piston. Until you hit 12:1 compression super unleaded is the best fuel to run. After that it depends on how much compression + any other internal mods that only then will determine how much higher octane to use.

It doesnt take much more even at high compression, mixing race fuel, which depending on brand and rating could be from 100 to 115 octane. Even at 13:1-14:1 comp. most builders will say to mix race with super unlead to get the required octane. For example I run either phillips 109 or vpc12 mixed with 93---50/50. That is with a 13:1 compression and many internal mods; valves,cams porting etc.

Stick with super and your engine will last longer and run better. Then when you are ready to drop a couple of grand into the motor, you will also start paying the high price for race fuel, which will be a must. Enjoy it now while it's affordable.

About the only good thing that will come from running race fuel in your stock motored yfz is the topend will be cleaner than running with pump gas.  I mix with 50/50 so that there will be less carbon buildup on top of the piston and on the valves.  As far as performance increase, it won't happen until you go up in compression.