MBRP slip-on Jetting ?

[lucey]

I need a jetting setup for a MBRP slipon on my buddies 400EX ? One other thing as well, it is hard starting in cooler weather, what pilot jet should he be running, one size smaller ? Which main and needle setup ? Stock motor with a uni-filter ?

[cals400ex]

assuming he is running an air box lid and the altitude is normal, i would start with a keihin 152-155 mainjet and a keihin 42 pilot jet with around 2.5 turns out on the fuel skrew.

[lucey]

Altitude 1200 ft, stock airbox. Needle in the stock position i assume ? What is the stock pilot jet size ?

[cals400ex]

try a 152 keihin with needle in stock position.


a 40 or 42 pilot should work fine. stock is 38.

[lucey]

What is the stock jetting setup ?

[cals400ex]

stock jets:
148 keihin main
38 keihin pilot
needle clip in 3rd position
2.25 turns out on fuel skrew