Jetting Question

[Holeshot36]

I recently put on the outerwears air box cover on my 400ex and now it seems to be running rich could this be true? I thought that it would be running lean but its slower to get on the power now. btw its stock besides 10:1 piston and fmf silencer and it ran fine before the outerwears.

[4TraxRider]

Take it off again and see if it changes again, has it got noticably warmer or cooler since you last rode?

[cals400ex]

what color is the spark plug? i am assuming you rejetted when you put your pipe on?

[Glamis400ex]

If it seems rich, it probably is. You restricted the air flow a little, but still have the same fuel flow....=rich condition.

Problem solved

Glamis

[Holeshot36]

I put the stock cover back on and it runs fine i didn't notice any running temp differance. The plug looks good though i haven't rode it much with the outerwears. How am i restriction more air flow, i had the stock air box cover on before. I thought the more air the leaner is runs is this true? I have a 152 main jet since i put on my silencer vs 148 stock, i'll probably go back down to 150 and see what that does.

[cals400ex]

you will not need to go down on the main if you started with the piston, silencer, and air box lid in place. from what i gather, you now have the piston, silencer, and air box lid removed with the outerwear air box cover. i would think a 152 or a 155 would be the ticket. the more air you get, the leaner it will become.