How hard to jet for HMF slip-on pipe?

[2000400EX]

Hi guys, I've been tossing around the idea of getting an HMF slip-on for my 400EX. My motor is all stock with stock air box as well. The only thing I have is a K&N with an Outerwear on it. How hard is it to jet for these pipes? I know to test your jetting you need to hold a constant throttle position for a certain amount of time depending on what area of the powerband your testing for, but how long is long enough to hold the throttle in a certain position? I'm fairly mechanically inclined, but have never done jetting on quads before.

Also, have any of you that have the HMF slip-on, ever ridden at Silver Lake sand dunes and past the decible test?

[cals400ex]

you will probably need the quiet core if you have to pass a db test.


it shouldn't be that hard to jet. many of the members on here would be able to get you pretty close to where it needs to be.

[2000400EX]

anyone else?:confused:

[sniffthis400]

if you go to the hmf website they tell you how to jet it for either the slip or the full exhaust..it also will not be that hard