300ex ? might need jetting???

[300exjuggalo]

my 300ex, backfires , when i let off the throttle, i saw that other post , so is that mean my jetting is off, i have a cut out sparkarrester, and no air box lid, and i havent jeted it before, its all stock that, and it seems like its gettin to much gas, gas if i give it alot it bogs down, even when its not cold , and im not in the wrong gear.. thanks for any hlp

[swamprider7]

You say that you have the airbox removed, spark arrrestor removed, and stock jetting! You are definitely not getting too much gas. You are not getting enough. Your quad is definitely running lean. Go up a few sizes on the main jet, lower the needle clip one notch, and turn the air screw out about 1/2 a turn. That should put you in the ballpark. Then do a plug test (check the color, light brown is perfect) and adjust the air screw as needed.

[300exjuggalo]

i dont no how to do it, and i dont got a jet, kit so i dont have any other jets, and im a poooooor arse , plus im savin for my 400ex

[300exjuggalo]

so i dont really no how to change the needles, i just no about it, :( im tryin to learn thou, thanks for the help thou thank you:macho

[Ryan]

Why don't you just put back on your spark arrester and air box lid?

[300exjuggalo]

cant put spark aresstor back on, cut it off, its a 300ex, its cut off and the lid i could but it still would be like that

[fuddrucker]

If you have ever taken your head pipe off, you might need to replace the gasket (round metal ring that gets squashed into place when installing head pipe) between your header and pipe.

[Loeryder]

Putting your airbox lid back on will definitely help, may not fix it 100%.

The only thing thats gonna fix it is buying the $8 main jet and replacing it, then the adjustments that were mentioned will be an improvement.

Either that or keep riding it like this and you'll be building a new motor before you get that 400EX.

You could also drop it off at a dealer and let them properly jet it for you for about $120-$150.

Your choice really.

[darrell43031]

man jets are expensive in illi aim't they!? here in ohio there only $4.25 plus tax. plus there real easy to install. but there right atleast put the airbox lid back on or it'll eat your cylinder in no time. cause every peace of dust you get near it just sucks it right into you carberator for one then right into your cylinder unless your have an outerwear cover in which case 8i would still put the lid back on so it'll cut back on the air flow and maybe stop your backfiring problem :cool: