Is 180 to big?

[maynard22]

I have a T4 slip-on, fmf headpipe, KandN filter, Airbox with holes cut in the lid. I took the bike to a local shop and he put a 180 jet in it and I have not been able to ride it and won't be able to ride it until Memorial Day weekend and I was just wondering if anyone has an opinion if this is to big or not. I live in Oklahoma and I have no idea what elevation i am at here. My bike is a 2002 400ex.

[sickmojave]

I would think that it's going to be way to rich.

[maynard22]

Any suggestions on what I should run it at.

[bwamos]

Aye, the common concensus is that a 400ex w/ aftermarket pipe, K&N air filter, w/o airbox lid is going to run between a 152 & 158 main jet.

Just do a search for "400ex main jetting". I'd use jet but 4 letter min on search.. lol.

[Chino886]

Are you going to be at the Little Sahara on Memorial Day? I think I am running a 155/45.

[smith_400ex_213]

if it runs how u want it to on top end dont mess with it...number dont mean much..just play wiht it untill it runs good...temperature and altiude plays a role too...

[duke416ex]

I have heard ppl say that some brands of jets are actually different sizes, but 180 sounds way to big. I have a t4, k&n, ported header, full p&p and a 416 kit and I run a 165 and I think I am a little rich.

[maynard22]

chino886 yes I will be at Little Sahara from saturday morning until monday afternoon, staying in the south campground, pulling a trailer with a big ***** ugly OU Sooner helmet on it, it's a buddies trailer and it is alot better than hauling the bikes on the little trailer I usually use.

[maynard22]

The bike starts up alot better with the 180 in it and seems to rev better when just sitting there, is this any indication that the jetting is alright? I know nothing about the carb part of things so if these comments and questions are stupid I apologize in advance.

[sickmojave]

the main has nothing to do with the way it starts. the only way you will know if the 180 is to big is to take it for a ride and check the plug. ;) you're not that far from me and with the stuff in my sig and 4~1" holes in the lid I run a 155 and it works great. I tried a 160 and it was to much.

[bwamos]

Air Screw/Pilot = Idle - 1/4
Needle = 1/4-3/4
Main Jet = 3/4 - Full

There's overlap, but that's roughly what the jets control.

1st get it to idle smooth.
Then Get the Main Jet.. full throttle right.
Then adjust the Needle.