avgas whos using it

[louis]

Just wanting to know how many people are running avgas 100LL(about 104 octane). With no problems and how long they have been running it. I just started to use it and I am mixing 32:1 ams oil dominator with a 188 main jet at 2000 feet and my digatron is still reading fine at 980 degrees on my 265 esr power valve with 180 compression. I know theres lots that dont run it but want to know from the people that do use the fuel what jets and oil mix they are using.

[deathman53]

it sounds like your main jet is very rich, I use a 170 in my motors, however I have a rich needle and pilot jet. For 180 psi, you can use 93/94 pumps gas, its 190 and over that race gas is needed. You are kicking the motor with the gas wide open, that is the only way to get a true compression reading? Alot of people use av gas. The extra gas octane doesn't increase your performance any, just lightens your wallet. I used to use a rich main in my bike, I later found out that my intake boot had a crack in it. I had a 205 in my 330 motor, when I rebuilt it with a new intake boot, it was terribly rich, it got dropped down to a 180. I don't think you need av/race gas, if your compression is that psi, thats right around the compression of the stock top end and they run fine on 93/94 pump gas.
I use 114 leaded w/ klotz tc-s snowmobile oil 32:1 in my bikes, the trike has a 170 main and quad is a 175 main, both are open airboxes. Both motors are nearly idenical, lrd 310pv, cr reeds, 39 pwk, cr igntion, the only difference is the pipe. And a 170 runs slighty rich too.

[number5]

I run av gas straight. I only need about half mix but its just easier that way to fill the jug with five gallons of it and its only $3.80 a gallon at local airport.

[csr250r]

my dad is a crop duster and he gets 100LL in by the truckload in the summer, i sometimes run half av, half premium in the summer in my 265, no problems so far. I did the same with my 240 blaster, never had ne problems.

[250r4life]

i've been runnin av with yamalube at 32:1 ofr 7 years now, and have friends who have been doing it for well over 10...

i dont agree with it just lightening your wallet... with pump gas i think youre much more prone to get a bad batch of gas, and also it breaks down a lot quicker... i personally wouldnt use pump gas that has sat for more than 3 weeks, but i wouldnt think twice about av gas that has sat for 2 months...

and you have a higher octane, which its better safe than sorry and aslo burns cooler...

[250r4life]

ps... on my duncan 265 i ran a 165 or so with a 36 carb... at sea level... you sound awful rich...

[86250rrider]

Originally posted by deathman53
it sounds like your main jet is very rich, I use a 170 in my motors, however I have a rich needle and pilot jet. For 180 psi, you can use 93/94 pumps gas, its 190 and over that race gas is needed. You are kicking the motor with the gas wide open, that is the only way to get a true compression reading? Alot of people use av gas. The extra gas octane doesn't increase your performance any, just lightens your wallet. I used to use a rich main in my bike, I later found out that my intake boot had a crack in it. I had a 205 in my 330 motor, when I rebuilt it with a new intake boot, it was terribly rich, it got dropped down to a 180. I don't think you need av/race gas, if your compression is that psi, thats right around the compression of the stock top end and they run fine on 93/94 pump gas.
I use 114 leaded w/ klotz tc-s snowmobile oil 32:1 in my bikes, the trike has a 170 main and quad is a 175 main, both are open airboxes. Both motors are nearly idenical, lrd 310pv, cr reeds, 39 pwk, cr igntion, the only difference is the pipe. And a 170 runs slighty rich too.


that 180 psi rule isnt necessarily true! my r had 190 psi on 94 octane and ran without detonation. then...it was ported by neil which raised and widened the exhaust ports which only yields 185 psi on the guage.when running a mix of 110 and 94 ...which yields around 102 pump octane it was detonating pretty bad. i went to 110 straight,problem solved. so...i feel the 185 or so is a guideline on stock unported motors only.the cylinder pressures are much higher after porting. but they dont read on a guage.i use my compression guage as a tool to verify the cylinder, ring condition ONLY .:D

[86250rrider]

and also...i m not sure but isnt aviation fuel oxygenated? which would lead to a richer jetting also.im running a 185 jet at 1800 ft.on a 38mm a/s on a ported engine and it burns perfect. a larger carb will need a larger jet than a smaller carb on the same engine due to the throat being larger and slowing down air flow.faster air.flow will increase the flow though the same size jet.a ported high compression engine with a small carb will yield unbelievable reponse and snap.but i will lack high-rpm performance. YOU CAN'T HAVE IT ALL....BUT YOU CAN COME CLOSE!:D

[GPracer2500]

100LL is not oxygenated.

[86250rrider]

cool...thanks:D

[louis]

well I am down to a 182 jet on my 38mm air striker with no air box and my temp is just over 1000 so I still can go a little more my needle is on the second from the bottom and it seems to be about right. I soon should have it dialed in. No problems keeping up with the 450r's with a hrc kit.