fmf help

[fasterblaster09]

i recently bought a used fmf megamax 2 or my 300ex,and i noticed they have some screw holes on the back of the pipe and was wondering if there is suppsoe to be a cover on the end?..thanks

[ethanp87]

yah it is supposed to be there but it is louder if it is not

[fasterblaster09]

d oyou know if it will make it smoke without it?..because it does blow a little smoke,and does it run better if it had the back cover on it?

[ethanp87]

IT would make it run a little better with it off but you might run to lean. with it out on a stock motor id run like a 130 main jet.or you might end up with problems.i went to a hmf slip on with k&n filter the mega max header .020 piston11:1 compwith a 135 main and i could take a stock 400 on the holeshot.the are both open ended pipes with the mega max back off so you should be fine like that with a 128 or 130 main jet

[fasterblaster09]

might be a stupid uestion,but i wont know unless i ask..how do i change the jet?

[MX174]

the easiest way i found so far on the 300 is if your gona just change the main jet, take the carb off, then unscrew your drain plug on the bottom of the bowl and your main jet is the short jet right on top, it should say on the side what size it is, i think a stock 300 is like a 125

[fasterblaster09]

ok thanks alot...does anyone know about how much it cost?

[watts16]

Originally posted by fasterblaster09
ok thanks alot...does anyone know about how much it cost?

the jet

3.00?

[fasterblaster09]

so that is all that is done whne they say its been "jetted"?...so change to a 128 main jet,and it will be jetted?

[MX174]

pretty much, youll be suprised how much better it runs with a bigger jet. My 300 had a 125 and is running a pipe k&n filter, it seemed a little sluggish on the throttle, i bought a 132 jet off of ethanp and it was really responsive, needs a airbox lid though because it sucks air when you give it alot of throttle quick