400ex winter jetting

[DamageInc]

I have a stock 2002 400ex that I have not ridden in winter yet, and I would like to know what others are running for a typical Wisconsin winter of ice riding. I already have a 42 pilot, but what about mains, air/fuel screw, and needle position?
thanks in advance...

If you haven't changed the air intake or the exhaust then leave it alone...should be fine. If anything go up 1 size on your main..

[DamageInc]

I see that you are in KY. Are you aware of the temps in WI winters? The coldest I have ridden in is -38F, but that's very rare. Below zero-F is very common though.

Originally posted by DamageInc
I see that you are in KY. Are you aware of the temps in WI winters? The coldest I have ridden in is -38F, but that's very rare. Below zero-F is very common though.

So how much moon shine do you drink before riding so that you trick your brain into thinkin its almost warm out:confused: :huh

[Doibugu2]

The 400's are jetted from the factory on the rich side for us. (I'm near CHI) So you should be okay. But if it starts running real hot, they you know your going to have to bump up the main. I would go buy the next couple of sizes bigger, just in case. Its about a 5 minute job to change the main.

[skemp]

Put a 40 pilot and 150 main in for winter riding if you are all stock.. Should do just fine. :)

[MOFO]

I run mine a tad rich in the summer, so in the winter, it works out well. Keep in mind that colder air is more dense (ie more air=leaner condition) so if anything, bump it up one size.

[hondarider2006]

running it to lean in the winter sucks, I burnt holes in all of my snowpants....and a couple pairs of regular pants...now that I have it jetted right, I am doing good, and no more holes

[trailburner]

Originally posted by hondarider2006
running it to lean in the winter sucks, I burnt holes in all of my snowpants....and a couple pairs of regular pants...now that I have it jetted right, I am doing good, and no more holes
LMFAO!!!!!! I thought I was the only one that happens to.....:D

[DamageInc]

Originally posted by Rico
So how much moon shine do you drink before riding so that you trick your brain into thinkin its almost warm out:confused: :huh

It's not that bad, you just have to dress properly.

I wonder if the stators on these things have enough juice to spare to run an electric shield. Anyone know?

[2001400ex]

While we're on the winter jetting subject. I need to know what to do as well. I live in northern Jersey...but I go snowmobiling in Watertown/Tug Hill NY, sometimes it can be -30below, on average in NY State it's about 15degrees. About 20-25 I'd say here in Jersey (I'm guessing) I have my 400 Jetted to the HMF Slip-On standards, except the guy told me to run a 165 main jet instead of a 175, anyone know if I should rejet or stay how I'm at for winter?

Oh yeah, almost forgot...I'm already having to mess with the choke to start the beast, it takes a few minutes to warm up. Today it wasn't that bad 50degrees out, it's been in the mid 30s lately though.

[cals400ex]

i would put a bigger pilot jet in. that may help for easier starting. a 165 keihin main jet is still to big for just a slip on. i would say a 160 would be plenty big even in the middle of winter. i noticed that when i moved my clip down one position on the needle the bike did not stumble or miss when it is cold outside. however, in the summer it is too rich in the 4th position.

[2001400ex]

Right now my clip is on the top position, should I move it down one as well?

[JOEX]

Originally posted by 2001400ex
Right now my clip is on the top position, should I move it down one as well?
:huh
Stock, the clip is in the third groove. cals400ex is saying to move it down one more (to raise the needle).

Joe

[DamageInc]

Thanks, guys, I think I'm gonna try a 42 pilot and 52 main, with needle raised one notch from stock, and see how that goes. Won't be long now until the river freezes....

[2001400ex]

Originally posted by JOEX
:huh
Stock, the clip is in the third groove. cals400ex is saying to move it down one more (to raise the needle).

Joe

So let me get this straight, should I move it down to the fourth groove? If I do won't it mess up everything because my exhaust has to be on the first clip, the only reason I'm concerned is because it seems like a big leap, down 3 clips:confused:

[cals400ex]

Originally posted by 2001400ex
So let me get this straight, should I move it down to the fourth groove? If I do won't it mess up everything because my exhaust has to be on the first clip, the only reason I'm concerned is because it seems like a big leap, down 3 clips:confused:

boy, you are confusing me. lol we are talking about the needle in the carb. there is 5 different positions that the clip on the needle can be located. the stock location of the clip is in the 3rd position. you do NOT want your clip on the 1st position. i don't even know if the bike will run there. it would be extremely lean. for you i think you will need an adjustment right between the 3rd and 4th positions since your all stock. personally if it was me, i would leave the clip in the 3rd position if your bike is stock. possibly you could put it in the 4th position in the middle of winter. i am running a 406 and the 4th position is too rich for me unless it is below 50 degrees. however, the 3rd is too lean as my headers tend to glow. you might want to consider buying a washer from C&D that will let you adjust your needle right between the 3rd and 4th positions. this is what i am doing. for the mainjet, i would not go bigger than a 150 keihin if you are using the stock exhaust with a closed airbox lid.

[2001400ex]

Ok, thanks.:p

[northeast400]

Just buy a dial-a-jet and be done with it. I see them on sleds all the time.

[DamageInc]

I rejetted last night and rode it today, so I thought I would bring this one back to the top for anyone interested.
All stock 400ex, I went to a 42 pilot, raised needle a notch(4th position), and went to a 152 main.
It was about 30 degrees when I went riding, and it ran perfect and started much easier. If it runs this good now, I don't know if it will be rich enough when it gets below zero; I might need to go a bit richer yet on the main.

[cals400ex]

i have to agree with you. i personally think you will be fine with the 152 in zero degree weather since you are all stock. one thing i want to point out that you said: you mentioned you moved the clip on the needle down to the 4th position and it runs good. i have talked to a few other people that say doing this made it run like crap. most of these people also have pipes on their bikes. i can understand it running bad in the warmer months, but moving the clip down to the 4th position in weather around 30 degrees or so should be just fine, even on a stock bike. i am glad you have had success with your jetting.