What is stock main jet??

[Evan]

What is the stock size main jet? Also if I take my air box lid off what main jet should I run? I plan on putting a 42 pilot and I am currently running a K&N air filter and that is it no pipe or anything.
Thanks for your help:cool:

[Wheelie]

The stock main jet size is #148. After you remove the lid, step up to a #150mj. BTW--Why are you stepping up to a #42 pilot jet without a pipe?

[Evan]

Thanks

I have heard that it helps starting in the cold, should I do it or just keep giving my starter a workout?

Try just goin up to a 40 and not a 42.

[Evan]

Well I got the jets from service honda, sent me 2 #148 mains, charged me for 1, and #150 main and 42 pilot. I put em in (the 42pilot and 148 main) The 42 helped alot but I still have to choke it sometimes, the 148 helped it run better, I can tell that it runs smoother and gives it a little snap, doesnt bog so much or spark nock like it used too. A #152 main was in it just as I suspected.
It still doesnt run like I expected it too. I have ridden some stock 400s that when you peged it in 1st and 2nd it would stand up and pick the front a little in 3rd. Mine will barely pick the front end if I peg it in 1st. Any suggestions?? I got a slipon on the way but I dont expect it to help that much. Right now I have #148 main 42 pilot, K&N with outerwear, lid on, stock pipe, running Castrol Syntec oil(not that makes a difference) stock gearing, 20 inch holeshots.

[Wheelie]

What elevation are you at? Are you running 92+ octane fuel?

[Evan]

Some where around 500ft I belive. I run 106 or better most of the time but sometimes I run 87 if I am to lazy to travel 30 miles to get the race fuel.

[MIKE400EX]

X-Rider Have you had any problems using the Castrol Syntec oil in your quad? That oil has a lot of additives that are not "friendly" with wet clutches. Just curious.

[Evan]

Nope but this is my first time running it, and have over 100 miles on it.

[Wheelie]

Don't run any less than 91 octane in your quad, 87 octane will cause pinging.

Try a #148 or #150 main jet. If you remove your airbox lid with the stock silencer use a #152.

[Evan]

I have a 148 in it now and just removed the airbox lid. I will be putting a PC slip on soon so I will be rejetting. A 152 was in it when I go it and that was when it would nock a little. It doesnt do it now that I have a 148 in it and it runs great.

[SGA]

Now i'm curious. Why would you drop down to a 138 main when the stock main is a 148? Mine ran like a scalded cat when it was pure stock. With the pipe, modded air box lid and foam filter, I run a 160 main and a 40 pilot. Needle clip in center slot. Had a 165 main in it at first, but it felt a little sluggish on top end. Switched to the 160 and it took off! Plug color seems o/k. Might bump it up to a 162 for safety though.By the way I ride about 100ft above sea level. Oh yea, I always run high test, 93 octane.

[Evan]

OOps I meant 148 main sorry.