Hello, I am doing some work on a kx 250 and was wondering the fuel to oil ratio. Also what octane fuel should I use?

Let me know.

Thanks

Go here and enter the year, motor size and model or vin number. Kawasaki Specs

I believe most run 32:1 but it depends on the owner and if they have rejeted the bike for a different mix. For my bike 90 octane or above is recommended.

91 or more octane is fine. You can run any where from 32:1 to 40:1 with no problems.

My friend has a kx 250 and from the riders I know They say premium, It is a high performance engine put in the good gas you will get high output . But if you ran 87 octane you might not even notice it. Just what ive been told but i put premium in my bike and all my friend use it also so anything in the 90,s is good

99 kx 250...91 octane (chevron) Oil 52:1 Golden Spectro full synth.. I may be wrong, but I think the brand of oil plays a part in how you mix..

Golden Spectro 42:1 with 93 octane.

What year KX250 is it?  In general, super unleaded is recommended, but I have read a few people mention that a certain model may ping under high stress or load, even when jetted  properly.  I have seen more than one person mention that on a 2005 KX250.

the machine shop i got to said the ethanol in the fuel raises exhaust temp which is really bad for a 2 storke and could make a piston fail on the exhaust side. my piston melted onto the cylinder from it getting so hot. but that wasnt the whole problem, why it was so hot, it just helped alot. he said to run a premium and race gas mix to help this, race gas will make it run much cooler b/c of precise ignition.

I always run at least the highest pump octane I can find. This year I'm going to run c12 race fuel mixed 50/50 with 93 octane pump fuel. I run Motul pre-mix at 40/1.