WR250F Octane

[prorider]

which octane of fuel should i use on my 04 wr250f? will i damage the bike if i use the wrong Fuel?.

[grayracer513]

You should use gasoline of at least the octane specified in the manual, which I believe is the same as that spec'd for the YZF's: 91-92 octane pump gas. (Note that the manual may actually say 95, but t hat would be rated by a means not used in the U.S. Pump gas labeled 91 or higher is good) I spite of what anyone may say to the contrary, octane in excess of that required will neither help nor harm the engine or it's operation. Certain individual fuels might, but not due to the octane number.

Yes, you can potentially damage the engine if you use a gas with too little octane (resistance to detonation) and allow it to ping excessively while running it. It can have varying results ranging from poor performance to a physically broken engine.