sorry for the question but i dont know who to ask, what gas (87 or 91) should i use on my 91cbr f2, and what would be the reason.
thanks for your help and knowledge!

 

for that bike you could proly just use 87 octane becuase of the lower compression, but for the newer bikes you should use 91 or 92 because of the high compression. the octane rating is basically the amount of time it takes for it to burn. 87 oatane burns faster then 92 octane. thats about the simplest i could put it.

 

Im pretty sure it says to use 87 Octane. Even for the new ones it says that.

 

LOL! i just sat on a 2005 R6 at the dealer a few days ago it said right on the F'n gas tank! USE 91 OCTANE FUEL..
their is a reason they make 91 and 92 octane ya know!

 

Well the 99-02 manual I have setting in front of me says to use a fuel grade of 86 Octane

It says 91 for UK models but not for USA models.

Even the 06 model F4i's call for 87 octane.

He is talking about Honda not Yamaha.

If you didnt know this as well, the higher octane gasses have cleaners in them too. They dont just burn differently.

 

Best idea for each bike is to refer to the owners manual. I have a 95 900 and always run 89 octane, the reason i run 89 instead of 87 is i ride in temps above 95F degrees, sometimes 115 degrees. In cool weather i'm sure my bike would do well on 87 octane.

When in doubt... read the instructions

 

Check this website out. It will tell you all you need to know about the dreaded octane question.

 

i couldnt open that link! will try later.
but what would be the consequences of using a different octane on your bike, in my case a 91 F2 using higher octane gas?

 

If you use to low of an octane you will get pre-detonation which means the gas will explode due to compression instead of the spark plug igniting it. However if you go to high then the fuel won't fully burn even with the spark plug thus robbing you of some HP. Best way to go is to run the lowest octane that your motor doesn't make a pinging sound (pre-det) with.

 

im more of a car guy but i know a 10-1 compression car likes 93 octane fuel... our bikes are 11.something- 1 right? either way my bike only gets premium fuel. you take care of your bike and your bike will take care of you


Keep the rubber side down