Jetting....

[WheelieMan4]

Well I know everyone hates these threads, but I really don't know where to start. Ok I have an HMF Slip-On and a K&N Air Filter. I dont want to waste the money on a jet kit, so im going to buy the jets sepperately. I think i should go with about a 42 pilot and then like around 180 main...? What do you guys think, and also what about the needle? Thanks alot...Josh

[400exrider707]

Assuming your going to not run the lid??? Then I would start with a 155 main, 40 pilot, move the clip on the needle down to the 4th notch (down one) and then the mixture screw should be around 2 1/2 turns out from bottomed. Start there and see how it runs. 180main is WAY to big for a slip on. Most fully done up 440s dont run that big of a main. I dont know what the guys at HMF were smoking when they came up with jetting recommendations for the 400ex pipes...

[WheelieMan4]

lol, ok thanks. Actually i am running with my lid on because i ride in some really dusty conditions...but i will try to start lower then..,

[400exstud]

I am running a FULL HMF w/quiet core, K&N, with the airbox lid on. Right now it has a 160 in it and it still bogs down so I am going to a 152. You should be around a 152 - 155 because you arn't running a quiet core (I assume).