what octane

[400exrider99]

what octane do i need to run if a have a 10:1 , 11:1 ,or 12:1 compresion ratio

[Honda#4]

11:1 or higher race gas

[ZeroLogic]

11:1 compression you can run in pump gas I thought.:confused:

[fitethesystom]

that's what i thought too.....and what i've heard.....

[2004exrider]

11:1 and under you can safely run 93 octane.
Anything above that you have to run a higher octane.

Jimmy

[aviator4]

JE Recommends 110 Octane "blue" race fuel for their 12:1 piston. I've been running that on mine for some time now and haven't had any problems.

I even has a sticker made for the plastic around the gas take opening that says "Race Fuel only - 110 Octane or Higher" - just in case someone that has borrowed my bike has to re-fuel it. So far it's saved it at least once. I almost ended up with a tank of 87!!

[bwamos]

It depends on the ATV.

Premium Pump
Air Cooled = up to 11:1
Water Cooled = up to 12:1

Generally. Every quad model is a little different.

[400exrider99]

y whould it matter on the atv

[CHEVYZ]

I was considering putting in a 12:1 compression piston ( Wiseco) in my 400EX when I turn it into a 440. I was planning on running on pump gas..... however, if I can find someone to buy race fuel from, I will most likely run that along with a slightly higher compression piston. My question is, will it be safe to do so ( Run 12:1 and pump gas) ? I am hearing that it would not be OK... can anyone who has tried it verify this, or someone tell me something better to run? Also, what kind of performance difference would I see as compared to... say 11:1? Any help is greatly appreciated.

[DAVE14]

I run a 12.5 to1 440 & i put in 94 +an octane booster which claims to get you 7 points higher i havent had any ping or nothin so I guess its fine ,it runs strong & good Ide try race gas if I knew where to get it , other than a drag strip thats about 100 miles away & totally closed for the season.

[400exrider707]

Generally an air cooled motor like the EX you dont want to run higher than 11:1 on pump. On something like a liquid cooled 450R, or a machine with a more aggressive cam, 12:1 should be safe with pump gas. Octane booster is really deceiving. 7 points is only about a point and a half I believe. So now your up to 95ish. Thats really still not enough for 12.5:1 ratio, but if your having luck with it than good for you. I think you said your also running a stage 2 cam too correct? That will help too.

[nowukno]

I run a mix of 110 octane and 93 pump and never had any issues. I love the smell too. :p

[Quadboy350]

One of my buddies found out that higher octane fuel in the long run actually made the quad run sloppy. possible because of heat?

[fitethesystom]

higher octane = cooler running temperatures.

And higher octane fuel won't make an engine run sloppy....

[400exrider707]

Originally posted by fitethesystom
higher octane = cooler running temperatures.

And higher octane fuel won't make an engine run sloppy....

No but it will make it slightly harder to start.

[ZeroLogic]

Originally posted by 400exrider707
No but it will make it slightly harder to start.


How would it make it harder to start? (Not trying to be a **** just wondering lol.)

[400exrules]

Originally posted by 400exrider707
No but it will make it slightly harder to start.

no it wont....higher compression will make it harder to start, not race gas

[zeppelin]

higher octane gas make it harder to start because it has a higher flash point (which is why you use it with high comp pistons) it needs to be hotter for it to ignite, and it only makes it hard to start the first time each day, as soon as you get the motor to operateing temps though it will start just like it did will regular gas