hey guys, i just bought a 2001 YZ 250 and the guy who had it before me ran 110 octane fuel in it, i dont feel like burning a hole in my wallat everytime i go ridin for a tad better performance, so i wanna just run pump gas in it...i was woundering if there is any motocross guys in here who know more on the topic then i do.. i ran 87 in my 125 with no problems, but it never saw 110 octane... THANKS!

Do you know what kind of pistons and rings it has in it?
If it is a stock motor you should not have a prob. But if it has beentweeked it may need that high of octain to run right.

if it's a stock motor, run what the manufacture specifies. If they say 92, use 92. if it says 87 (most do) then use 87. you don't gain anything with higher octane fuel. if anything, you loose power.

the actual motor is stock except the piston and probably the cyclender (go figure) i am assuming that it has a wisco piston and rings just because thats usaully what everyone uses or oem..

I always run 100 octane in my CR250.

why? what is the difference between pump and 100? compression is only like 10:1

I wouldn't worry too much, just watch how it runs.