440 carb jetting

[Andrewcordle]

I am looking for a kind of base line to start jetting a 2004 400ex with a 440 kit, hotcams stage 2, white brothers pipe, open air filter lid, Wiesco piston, and a hotrods crank and rod. I am familiar with how to go about adjusting up or down, but need some info on where to start?. Any ideas???:confused:

[Andrewcordle]

anyone..... help:confused:

[Wheelie]

Here's my setup:

Powroll 440 Stroker/Hotcams Stg3--stroker cam/P&P head/E-series Slip-on/K&N w/open airbox and choke removed/stock carb


Jetting: 42 Pilot/175 Main/ Clip lowered one notch from stock.

Setup runs great, toying with the idea of going down to a 172 on the main.

[Andrewcordle]

Thanks for the help I will start from there.:)

[Andrewcordle]

Why no choke???

[GPracer2500]

Originally posted by Andrewcordle
Why no choke???

The point of removing the choke is to remove it as an obstruction within the carb's venturi. In other words: better airflow. With the right jetting and good starting technique most EXs can be started just fine without a choke (colder climates might be an exception).

[Wheelie]

What he said. Without the choke, I noticed better low end throttle response, and slightly more power throughout the rev range. I simply pump the throttle several times and it fires right up.


BTW--My jetting setup works great from 0-3000ft.

[Andrewcordle]

Awesome thanks for the info. This will help a lot.