400 jetting

[01400ex]

Ok,

I just got an 01 400ex and I love it. It came with a white bros e series slip on and thats it. Well since then I've added a k&n filter and ground down the header welds and it ran like ****. I could be climing a hill and it studder and bog big time. So I took of the air box lid and it ran good for a while. But now it studdering again and can't pull up a wheelie in 3rd when I could before.
Anyhow I took out the plug and its white.
I know this means it is lean but what all would I have to change? Just the main?

What size jet should I go up to it has stock jetting now a 148 main.

Later Ryan H.

[JOEX]

I have the same set up....
Change the main to 152 or 155 with the lid on.
It wouldn't hurt to go to a 40 pilot either.
I raised the needle one notch on mine but most people don't think it's neccessary;)
If it's been running with that set up for awhile with the 148 there is a possibility there could be some damage. I don't know exactly what, someone else would have to say.

Joe

[dingo]

I have the same set up I went to a 155 and it worked for me. Remember that Dynojet and Honda jets have different size numbers for there jets

[trxex]

148,waaaaay to lean.try a 160 and work your way down

[trailburner]

Originally posted by trxex
148,waaaaay to lean.try a 160 and work your way down
trxex is right....Im runing about the same set up as you, I have 12- discs in my E-series & i use a 165 in winter & a 160 in summer, runes great!!!!