Octane rating at 7000 feet and up?

[Crasher]

Without ever looking, I always used 87-88 octane in my Rev 800HO.

Been running great for 3 years. Looked on the cap and it says recommended 91 octane.

So, in goes 91 octane. Sled just does not run right at WOT. It surges, kinda like Raw, Raw, Raw at WOT. Otherise runs perfect. Just started this with 91 octane.

I have check and changed just about everything except putting back in 87 octane. Could higher octane cause this?

At 7000 feet would 87 octane be acceptable.

 

[BackCountryBob]

We ride 8-12,000 on 85, have used 91 to see if any diference and could not tell of any. Our sleds are stock compression, 135.

BCB

 

[PowderHound07]

i had an 07 with the 800r and only ran 85... tried 91 a couple times but could never tell a difference in performance

 

[Crasher]

Thanks!!!

 

[portgrinder]

you never will get a difference in performance....you will just wreck your motor.

Better fuel (normal stuff) does not give you more power, it allows the engine to survive at a higher state of tune = more power.

Doubtfull that changing octane would give you these issues. unless its been sitting forever. sounds like jetting to me, maybe lean.

one thing a guy needs to remember about sledding in the hills, is yes elevation allows you to run less octane. BUT if you hold it open for 5 minutes vs. 30 second bursts back home on the flatland....that theory goes out the window