400ex

[skatrdude20]

Yea Im buying a 1999 400ex cuz i just sold my 300, and it says it has a 11:1 compression piston. Does this mean I cant run tegular unleaded pump gas, or do I have to run a higher grade gas? Thanks

[47501exracer]

You are supposed to run 93 octane. That's what I use and I think most others do also.

[nosliw]

premium pump gas is good enough for 11:1

[CaliLifeStyle]

I'm probably going to pay for it later, but I use 87 because gas prices are so high.

[2muchquad]

I'm probably going to pay for it later, but I use 87 because gas prices are so high

...lol i hear ya!:D

[reyes]

Hey guys i just recently bought a 400 EX runs like a raped ape but i notice the engine valves are a little loud is that normal? also i took the exhaust tip baffle off is that going to do any harm?
Thanks.