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View Full Version : jetting help?



DIRTRIDER22
03-25-2008, 06:58 PM
I just put a hmf slip on exhaust on my stock 2007 400ex, Im wondering what size jet i need to up to? I will be running a k and n or a uni with no lid.

Young_Gun1
03-25-2008, 07:57 PM
not right now but i can tell you tomorrow! what is your elavation?

hornetgod13
03-25-2008, 08:11 PM
42K Pilot and 158K Main would be a good start. Altitude and riding temperature may require you to go up or down one jet size.

TRXRacer1
03-25-2008, 08:14 PM
The 38 pilot is fine if you turn the mix screw out a little, go with a 40 or 42 if you want to leave it alone. I'd also start with a 158 main and do some plug chops to see how you're doing. Probably move the needle up one notch too.