160 main and a......

[WheelieMan4]

I have a HMF slip on and a k&n air filter....i put in a 160 main jet, but what else would u recomend, i was thinking about a 42 pilot and move the clip up one??? please help thanks...

[rneal]

Move the clip down one position.

[400exstud]

You may be able to get a tad more power by using a 158K, bit then again you may blow it up. A 160 does sound in the general area though. I have a 155K in mine with a full HMF, quiet core, K&N filter, and airbox lid ON.

[prepracing]

I was thinking the stock pilot jet on 400ex was a 42 ?

[400EXBill]

Nope. 38.

[WheelieMan4]

this is a dyno jet, and ive heard that they are different from the keihen jets...so what should i use in a dyno jet...thanks

[400EXBill]

Oh, your right. They are different. I don't know DynoJet sizes. I stayed with keihin jets.

[WheelieMan4]

ok so im going to order some keihin jets instead now, the dynos were just some from my friends 450r that he used at first until he got keihin. i am going to order a 42 pilot jet for sure, and im thinking about 3 main jets -- like a 152, a 155, and a 158? thanks