Go Juice

[riffraff]

AVgas (aviation gasoline) is not made to make HP it's made to stop planes falling from the sky.

         

No gas is made to make HP and planes don't fall out of the sky  Main reason I use avgas is because I'm an aircraft mechanic and have a pretty much unlimited supply of it, been using it for 25 years. Avgas also has stricter quality-control standards, is formulated for anti-detonation and has stabilizers added to keep it from going bad.

[mrhp]

I agree whole heartedly that avgas, when used correctly, is an excellent two stroke fuel.

If the compression, pipe arrangement, and jetting is correct, my personal findings are avgas will produce better power than pump.

Furthermore, it's strictly regulated (well...much more so than pump gas), extremely consistent, highly resistant to detonation, and relatively cheap.

It also stores well.

Are there fuels out there that produce more power? Yes.
How much more?
If both set ups are optimized for that fuel correctly...usually not more than 3-4 percent improvement best case.

Disclaimer...some fuels produced by elf, which I have not tested, show an oxygen content that's huge....and in turn may produce much, much more power (at huge prices)

[2T Institute]

No gas is made to make HP and planes don't fall out of the sky  Main reason I use avgas is because I'm an aircraft mechanic and have a pretty much unlimited supply of it, been using it for 25 years. Avgas also has stricter quality-control standards, is formulated for anti-detonation and has stabilizers added to keep it from going bad.

Avgas only has a specific gravity of 0.73 versus 0.78 for our 98 octane ULP. Avgas burns very slowly, ULP burns very fast. Avgas is not 'formulated' it just has lead and an anti-icing agent.The 'strict quality controls' are not that stringent and more to do with batch numbers etc(we had a bad batch here recently and all piston engine aircraft were grounded).
But none of that makes HP it's simply to stop Lycoming engines detonating.
Just because you will run a bigger jet on avgas doesn't mean your making more HP.
We have BP98 pump fuel that we can tune to the limit on, 100% consistent from servo to servo month to month. 
Truth is these days avgas is old hat and there are far better fuels to use.

[riffraff]

Truth is these days avgas is old hat and there are far better fuels to use.

It may be old hat but so is my bike, aircooled non-power valved '79 YZ490, so I don't think there is any better fuel to use for my bike... and did I mention that I get it free, how much better can you get 

[opfermanmotors]

How did you get a 79 YZ490?

[ford832]

It would suck to have to buy special fuel rather than just stop at the gas station for a little supreme while on the way to go riding.I guess we must be fortunate here as ethanol isn't an issue-yet.

[juliend]

Anyone using toluene? I been hearing a lot about it lately. Usually 5 - 10% mixed with premium pump gas.

[riffraff]

    Ooops, meant an '89, that's what I get for early morning posts

[125mx.com]

in UK we only have choice of unleaded or super unleaded.. whats AV gas?

I'm in the UK dude and have the choice of almost all race fuels, do a search, you can get VP, ELF,  Sunoco etc. BP sell a 102 pump fuel as well.

I have tried to get E85 working but found to many problems, one was the huge jets needed to run it, we even ran our sx125 without a mainjet installed ?  We worked out we cold get about 20min's max from a full tank, but we found it caused a whole lot of wear to piston and ring, almost has the feeling of being 'dry'  It also eat crankseals !

Avgas was good when we could get it, we ran that 100% mixed with motul800 @25:1  But its getting harder and harder to find the stuff.

Been experimenting with other stuff recently and found some real good additives in the, well lets say 'solvent' family of chemicals. Melted a few slugs along the way, but now I'm happy running my mix in all our 2st's and its ultra reliable. Pump gas in the UK sucks for anyone running decent motors but most guys dont bother with fuel as they just think fuel is 'fuel' and fill up at their local forecourt. (all the better for us )