What octane fuel should I be running in my 2002 yamaha warrior yfm350? I've been using 87 and it seems to be running fine, but I've heard I should use 91. Just curious to hear opinions, thanks.

 

IMHO, I run high test in all my air cooled machines. I feel there's less of a chance of preignition.

 

anywhere 91 and above up to 95 should be fine...

 

Do not run over 91 in a stock warrior...it does not help that stock motor to run race gas.. its air cooled and it will run hotter with race gas...you dont need anything over 91 unless your running 11.5.1 pistion or higher..the wifes warrior has a 12.1 pistion in it.. and it has to have race gas...and she has to be carfull she dont get it hot just trail ridding..

 

Remember everyone. Octane does not mean more power. You will not get more power out of 91 octane than you will out of 87 octane. In fact if your bike will run off of 87 octane you will actually start to lose power by going higher in octane.

Octane is just a rating that is given to fuel that is derived from the fuels ability to resist ignition. The higher the octane the higher the fuels ability to resist ignition. Your high compression engines develop more heat, therefore the need for higher octane

The petroleum companies started the "premium" and "high test" campaign long ago to get more dollars out of us. When I was in the fuel business years ago we would sell premium for 16 cents more per gallon than regular unleaded. The actual cost increase of premium over regular gas was around 4.5 to 6 cents per gallon. So now you see why they push the premiem fuels now!. Most major fuel outlets also put in the same amount of cleaners in their regular unleaded as they do their premium now. In fact it is a law that they have a certain amount of cleaner in all grades of pump fuel.

 

Doyle is right once again.

 

Thanks guys, I found all these responses very helpful. However I suppose what I meant to ask is I'm not hurting it by running 87 am I? Also I left a few things out, It's 100% stock, trail driven (with a decent amount of open spots to hammer down on the throttle to cool it off as well).

 

Your ok running 87[img]i/expressions/face-icon-small-smile.gif[/img]

 

Your fine with 87.
If you run too high of octane and not do a timing bump the gas will burn in the pipe. I've seen race cars that are glowing red from the exhaust manifold to the end of the tail pipe because of too high of octane.