AVgas

[diehardrider]

I know this has been covered a few times but I am able to get avgas for free and i have to pay for pump gas.
SHould i run avgas or not?
I never ran it in my 250r because i alway heard it may react with the premix.

What do you all think.
My 400ex is brand new and i havtn even gon through a tank of gas yet. SO im trying to decide what to do.

Any information would be great.

[fourtrax400ex]

i have running avgas (100LL, its blue is it what you talk about?)several time in my 426ex with no problem, i try many combo of gas, run 100% av gas, 50/50 with premium pump gas, octane boost... i think i have the best result with the 50/50 100ll and 92octane pump gas with a small amount of octane boost. you need hi compression perhaps to burn it. i have heard that 100 ll is a ''dry'' gas, and dont oil the motor like pump gas, so it's why a put octane boost in it to help lubrification of piston. when im running on 100% av gas, the ring of my piston seems to worn more quickly(the compression of motor have drop after couple of weeks, but it was a new motor so maybe it's not the avgas). av gas have less lead thant pump gas, so it's lightweight, so you have to check your jetting. put one more size on the main jet thant pump gas, the motor wont bug even if your too rich, and the piston will be colder, you will have better rpm response also i found with av gas. personnally, i think that if you above 11:1 in compression ration, you dont need it and you will loose performance, but if you have 10.8:1 or 11:1 piston, i think that 50/50 ration mix is the way to go to be safe. im not a professionnal of gas mix, i only tell you my experience and what i have seen on the web about 100ll, check on a search engine there some good information on the web.

hope its helps

[RED121572]

Ask the guy who runs Four Stroke Tech about AVGAS. ;)

[Steven]

I too am taking an interust in agvas.

One thing I saw in the above post that was incorrect was the information about the lead.

Pump gas is unleaded and what attracts me to avgas is that its leaded. It contains 2 grams of lead per gallon, which promotes better lubrication to the top end assembly than pump gas.

Its also cheap.

Steve

[diehardrider]

thanks for all the replies.
Another thing that i think is a plus in avgas that you can store it for a long time before it goes bad.

[White_Knuckles]

I work at an airport, talking with the mechanics I found they use AVgas to store all their power toys. It dosesn't break down and turn to s**t after months of storage. They did say it was lacking some detergent additives but didn't mention lead. They do switch to conventional fuel for operating but perfer it to stabilizer products for storage of all power gear even lawnmowers.

[fourtrax400ex]

about the lead, 100ll mean Low Lead, and i know that 1 gallons of avgas weight less than one gallon of pump gas, this is why i said that maybe there more lead in pump gas but maybe im wrong. i found that on the web check at www.osbornauto.com/racing/race2avgas.htm there some good info but the guy seems to not like avgas, but said that it wont hurt your motor.


''Avgas is less dense than most racing gasolines. Instead of weighing about 6.1 to 6.3 pounds per gallon like racing gasoline, it weighs 5.8 to 5.9 pounds per gallon. The racer must compensate for this by changing to richer (larger) jets in the carburetor when changing from racing gasoline to avgas.''

[diehardrider]

that what i was trying to find out wether it will be harmful or not.
It seem to me that it may not make the best power but it will not be harmful.
thanks for all the info.

[Mxbubs]

I use to always run AV gas in my 4ooex.....never had a problem.