Race gas in a 400ex

[lukac_780]

ok so im running 87 octane in my 04 400ex with pipes and jets
its runnin like crap
i race
can i just go ahead and run race gas
or do i have to change ANYTHING?
thanks guys!

[lukac_780]

wow what a waste of a website

[Pomarico77]

Its not the octane of the gas bud, its your jetting guaranteed, Unless you have a some head work, hi-comp pistion you should not have to run straight race gas. You prob could run 93 oct. would run cleaner. Try re-jetting..putting an aftermarket filter in and removing the box lid.

Whats the specs? Pipe brand?, slip on or full?? Jet #'s? Filter..Stock?

[lukac_780]

stock filter
full curtis sparks exhaust and idk on the jetting
when i take the air box lid off dont i have to tune it?

[Pomarico77]

If you dont know the jetting specs, fine out what you should use for jets, Call sparks, order a filter and ask them what jets you should be running.
When you put ur exhaust on it should be jetter properly or it will run like shit, What you did with the exhaust was to let the engine ex-hale better now u have to get it to inhale. Open the lid, or cut it, then put a new FOAM filter in it, Re-jet to SPARKS specs and go riding.

If it still runs like crap, u may have some issues..