regular or premium gas with twins????

[Alberta Sledder]

I have m8 with air box mod and jaws twins.

Thanks

 

[sprockethead]

I always run at least premium in all my sleds. Little extra just worth some piece of mind, JM2C.

 

[mtn_extreme]

air box and twins will work better with higher octane. Run premium.

 

[alexhack]

I ran premium in my M8 and it created a slight bog. Switched back to regular and the bog is gone. Arctic Cat recomends 87 octane due to their sleds having a low compression ratio.

800cc = 6.39:1
1000cc = 6.41:1

You need higher compression to use higher octane. Higher octane = higher burning point. Higher compression ratio needed to get the fuel/air mixture to optimum temp before ignition. The twin pipes shouldn't make your engine utilize higher octane any better compared to stock. Unless you run a high compression head, which I've heard doesn't work well with the Jaws twins, you might as well save you cash and get regular fuel. IMO

 

[Sledbrain2]

There may be some timing issues that particular models need higher octane. I think that is why some aftermarket companys have you run 92 with twin pipes. Just a thaught, I would run what they tell you to run.

 

[mtn_extreme]

Twin jaws will cause more back pressure.

 

[Alberta Sledder]

Thanks for the replies... but

Shouldn't premium help since pipes effectively increase the compression ratio in a two-stoke engine? I am I wrong? All I know is that after todays ride, it seemed to lack on the topend with regular

 

[alexhack]

It definatly won't hurt to try premium. After all it is only 4-5 octane more. The pipes might cause enough back pressure to increase the compression ratio enough.

 

[harrysmith500]

run premium.. it may run the same as it does on regular gas. but it will run cooler for sure...