PDA

View Full Version : Jetting question


FoxMxRiders
03-14-2006, 06:43 PM
Want to know what main jet I will be able to run with this setup :

Stock motor
Uni Filter
Open Box
Yosh Slipon

0-1000' elevation
Temp around 32F

Maybe with a 170 I will be ok?!?

This is for a 400ex

Thanks
b_watts3
03-14-2006, 08:49 PM
well i have a hmf slip on with 416 engine and i use a 152 main jet and it does fine...
ohsobad_chevy
03-15-2006, 01:07 PM
I would have to say that a 170 does sound a little rich, I would start with a 155 main and a 40 pilot with the needle pos 2nd down from the top. That should get you pretty close. Keep in mind the temperature being 32F as well, this will make it run a little leaner.
FoxMxRiders
03-15-2006, 01:25 PM
I already have a 42 pilot.

I have checked on a pipe review that with a dyno and a K&N,the used a 155main jet then im the lid off and the temp is below 32F....

Someone can help me?? don't want to buy 10 mainjets.

Do you really think that I will have to adjust my needle? (stock one)
ohsobad_chevy
03-15-2006, 03:14 PM
Man, I know exactly how you feel right now, but at the same time, you will not get it exact on the first try, unless you are extremely lucky. You will know when you have it right, just experiment with it, after all you will gain good knowledge as well.
04'400ex'er
03-15-2006, 03:25 PM
Stay with the 42 pilot for now... that might possibly be a little rich but not much.

As for the main, start at a 155 and then bump up to a 158 if it will take more fuel then keep goin richer. You shouldnt take any larger than prob a 165 at the most.
I would say a 158 will probably be spot on for you.

If I was you I would buy a 45 pilot, 152, 155, 158, 160, 162, and 165 main jets. That will save you alot of trouble because you will have the jets you need for awhile instead of running to the shop all the time.
FoxMxRiders
03-15-2006, 03:26 PM
Yeah I know how to deal with a carburator no problem with that.I study in Atv mechanic and know how that work;)

I was just taking of my dynojet kit to sell it (because I don't think that have the value) and want to know around where I will be ok in my jetting.

So I will take 155,160,165,170,175

and I will be correct I think

Thanks