What Jet??? 11.1, st. 2 cam, mildly ported head...

[sleepin400]

On a 400ex, what jet do you think I should run?

11.1 piston
Hotcam stage 2
mildly ported head (stock valve size, just cleaned up a bit)
Full exhaust
Filter

I raised the neddle down one notch (supposed to help with mid range and low power)

I was told to try a 155 from a decent sorce but that just doesn't sound like enough.

My friends who have been messing with these for years say a 168

I have a 165 and was going to try that.

What do you guys think?

thanks

[bpimpdaddy21]

I am going to be doing the same also, so I will be curious also to know what a good starting point for this would be. I have 160 in mine right now with pipe, filter, ehs lid, and would think that with the higher compression, you would possibly need a size bigger jet. I am interested here also.....

[cals400ex]

going from a stock bike to a 406 with stage 2 hotcam, i needed to go up one size on my jetting. the pipe and removed air box lid makes more of a difference for jetting. when you add motor, you suck gas through the jets. in other words, more gas is being sucked thru that same jet even though it is the same size.


sleepin-- try:

158-160 keihin mainjet
4th clip position on needle
42 pilot jet
2.75 turns out from lightly seated on the fuel screw

if you remove the air box lid, you may want to start with a 160-162 keihin mainjet. remember, dynojets are numbered differently.