Has anyone had success using AV or Race gas in their p650? I would assume that their might be a slight power loss using one of the two, but the reason I am asking is because here in Oregon, the gas stations have oxygenated fuel during the winter months. I have found that this gums up carbs (in past years). Will anything on the P650 be negativily affected by the lead in AV or race gas?

 

You can get unleaded race fuels. Also, you can buy pure, low octane race fuels (less than 100 octane) that would be better than the 105/108/110 octane that most "race gas" has. It will also be cheaper.

DO NOT USE AVAITION GAS. It is designed for a specific constant RPM at extremely high altitudes. Not for stop and go ATVing on the ground.

 

Maybe AV gas would be okay for me since I am "all throttle"....in fact, I can't remember the last time I actually had to use my brakes on my p650... (=

 

I know the feeling. I have to keep my banshee pinned to get anything out of it. What a piece[img]i/expressions/face-icon-small-wink.gif[/img].

Speaking of banshees, yours looks absolutely sweet!!!

 

I live in Socal and we have no choice but to use oxygenated gas year round.I've never seen any problems with it gumming up carbs...it does evaporate very quickly in the summer though.

I wouldn't run avgas.It has a lot of alcohol in it to keep any water in the tank from freezing at high altitudes,frozen fuel lines are a bad thing at 15,000ft!

The alcohol in it could eat your rubber lines and your float needle.

 

This is a stock P-650? Why use AV-gas? No need, and it is PRICEY.

 

I'm reading a lot of false information on avgas here. Avgas DOES NOT contain alky as previously stated. 100LL avgas is formulated differently than autogas but not for the reasons stated. The engines this stuff is usually used in are air cooled and have different requirments due to altitude changes. Fuel in a small plane is tested before each take off and if you find any sign of water or other contamination you don't start up until the problem is remedied. A lot of roundy round racers here use it for the higher octane but add a silicone lubricant as avgas is deficient in this area.

The oxygenated fuels you speak of are oxygenated due to the addition of alcohol. This first began around 1979 or '80. The addition of alcohol was to be held to 5% or below but I've tested content over 16% in the past. Alky is cheaper to manufacture than gas so imagine!

Stick with pump gas unless you're building a race motor designed for an alternate fuel. It's all you need.

 

Dangerous, you are 100% correct here. Yes, AVgas gives you a higher octane rating, which helps the motor detonate properly, or in other words, helps keep pre-detonation to a minimum. It does not make for a bigger kick in the cylinder, it just keeps the fuel from firing before the spark plug sets the ignition sequence off. AVgas IS lacking in lubricants. Motorcylce engines work at much higher RPM ratings, and using AVgas without a lubricant additive is not a good thing.

If you are bent on using AVgas, go buy a can of 104 Octane boost. Follow the math on the can, and mix your fuel so you get somewhere near 97-100 octane. I would NOT go any higher. If you do, you risk the chance of the engine NOT firing because your octane levels could be high enough and your voltage ratings low enough that you do not get a complete burn when the cylinder needs it. This would be similar to retarding the timing.

The fact is, most machines today are designed, by engineers, to work at or about the 93 octane level. CDI boxes, voltage systems, and spark plug choices are made and installed on this criteria. Unless you are going to change most of the these items, then you are in essence changing the recipe...and doing so without ALL the ingredients. Things taste bad when you do this, right?

My .02 cents, and I am gone!

Chucky

 

This in not making sense in my mind. Are you suggesting adding 104 Octane boost to Avgas? That will just make the flashpoint higher. I just don't see one ever achieving 97-100 octane by what you stated. [img]i/expressions/face-icon-small-wink.gif[/img]

Just note that I not looking for a performance change due to a change in octane. I simply want "clean fuel" that is not going gum up my carbs. [img]i/expressions/face-icon-small-smile.gif[/img]

 

Sorry for confusing you, my bad.

"104" is a brand of Octane boost, not a measurement. Keep in mind, adding otcane raises your flashpoint, and ensures proper detonation. This is why higher octane fuel costs more. That...and fuel is a racket to begin with...

And, I was not suggesting adding to AVgas, I was talking about pumpgas. Stick with Texaco/Chevron/Shell. You won't get much cleaner than that...

Chucky