is this correct for a hmf

[400exrider26]

are these jet recomendations correct or sound correct for a 04 400ex when i get my hmf slip on with uni filter...
*main-165/170 Keihin Hex Head
*pilot? mabe a 42?
*Needle in the second clip position from the bottom
*3 turn out on the air fuel mixture screw

and then one site said-
*main-175 Keihin Hex Head
*3.5 turn out on the air fuel mixture screw

keep in mind this is for a stock 400 with just the uni and the hmf slip on

[MNTNMAN]

With a stock air box, I think that will be too rich. Try a 155 MJ +/- a size.

[2001400exrider]

i got the HMF full system and my jetting is,

- 175 main
- 2.5 turns out on air/fuel screw
- needle second clip from bottom

and i have a perfect plug....

i was wondering if i should goto a 42 pilot to gain a lil more low end...?

[bakeen]

I have the HMF slip on with stock header. They sent me a 165 and just putting that in (did nothing to the pilot or air screw)seemed to work fine except for sometimes after a jump when I got back on the throttle (about half throttle to 3/4rth's) it would bog down a bit. But I just put the clip in the 2nd from bottom position and I think that will fix it but I haven't been able to get back out and ride yet (putting new A-Arms on right now). But I know just with that setup I'm right in the ballpark and its probably only going to take a few minor adjustments to get it correct. I've heard with the stock header you need the 165, and if you have the full you need a 170 or 175.

[400exrider26]

any other opinions...

[muddy400EX]

Originally posted by bakeen
I have the HMF slip on with stock header. They sent me a 165 and just putting that in (did nothing to the pilot or air screw)seemed to work fine except for sometimes after a jump when I got back on the throttle (about half throttle to 3/4rth's) it would bog down a bit. But I just put the clip in the 2nd from bottom position and I think that will fix it but I haven't been able to get back out and ride yet (putting new A-Arms on right now). But I know just with that setup I'm right in the ballpark and its probably only going to take a few minor adjustments to get it correct. I've heard with the stock header you need the 165, and if you have the full you need a 170 or 175.


it helps to keep it revved a little in the air, thats what i do anyway:)

[bakeen]

Yea I keep on the gas but if I go to much then the back end gets to low. I didn't have to do it before the new pipe so I think the clip on the 2nd slot should fix it. Hopefully I'll get to try it out this weekend as long as its not hotter than hell outside.

[400exrider26]

come on i need to make sure im getting the right jets...

[morocca430]

I am running the full HMF system with a UNI using a 155 main jet. I haven't even messed with the fuel screw because its running perfectly. Of course I have the 38mm carb though instead of the 37mm. I can tell you though that this system kicks *** though, my quad is running like a champ.

[400exrider26]

i should defimntly change my needle when i jet it right?

[morocca430]

Just try changing the main jet first and see where that leaves you, what needs to be changed based on what the main jet has done for you. I pretty much got lucky the first time i jetted mine. I bought a 155 from a shop around here and after going through it all I did was put in the m/j and take it for a test drive to see how it ran and I haven't touched it since.

[400exrider26]

i got new info from hmf they say
-152 main jet, a 42 pilot, set the clip on the
second position from the bottom on the needle and set the fuel screw about 2
1/2 turns out
sound better then what i said before?

[400exrider26]

this new recomindation sound good>?

[morocca430]

yea it's better... even though it might not be right, you still might have to mess with the air/fuel screw or change some things here and there, it all depends man

[meanyellow03ex]

Mine was dyno tuned and needed a 170 to run safe with a vented airbox lid. 155 was lean on the top end. Needle is in second from bottom and 3 turns out on the screw.