440ex jetting questions

[Jennys440'Dale]

My fiance has a 1999 440ex with the following:
Wiesco piston, 11:1 comp.
Hot cam
Port and Polish
3 angle valve job
stock carb
Big Gun full exhaust
K&N filter with 6 one inch holes in the airbox lid

Now my questions is, for those of you have the same set-up , or almost the same set-up, what kind of main jet are you running? He is running a 45 pilot jet and the needle is in the middle. Right now we are up to a 185 main jet and it is still running lean. Just can't seem to get the jetting down. Any suggestions, comments??
:mad:

[powerslider]

What are your indications that it's lean? What plug are you running?

[Jennys440'Dale]

Hey Powerslider, aren't you supposed to go up to Silver Lake with us (WNF Gang)?

Anyways, Nick is running an NGK plug and everytime he pulls it out, it is almost clean (tip is still silver). HOpe you know what I mean?!

[powerslider]

Yeah I'll be there, you ready? What's the plug #? If it's the stock plug you need to go from the 8 to a 9 (colder) this will help with color. Don't be so concerned about plug color, I asume your running pump gas. Are you running an airbox lid or not?

I would try this set up with stock carb parts (not dynojet kits)

42 pilot
2 turns out on the fuel screw for a starting point
raise the needle to the 4th groove
I would say your close on the main but maybe a size or two large

You need to get a feel for how the motor pulls on top end, if it pulls right up to the rev limiter your good, if it lays down and quits pulling try adding or subtracting the airbox lid to see which way to go. If your lean it should run better with the lid on and if it's rich it will be better with the lid off.

[Jennys440'Dale]

Powerslider--Oh you better believe I am ready to go to Silver Lake! With all those toys, which one are you taking up there??

Nick is running 100 leaded fuel from the Airport here. It's the top end he is having trouble with as far as the jetting goes. Spits and sputters about 4-5th gear.

Yes, he is running an airbox lid. It just has six 1" holes on the top of the lid. He feels that his pilot jet is ok, he's just wondering if it unusual to go up to a 190 or higher on the main jet.

[buckeye400ex]

190 is pretty big. ?? I don't know. Is he cutting the engine off when running wide open too? You can't run it, then idle around back to the garage and check it. Need to shut it off when it's wide open, ala Winston Cup Stock car shutting it off after crossing the finish line

[Jennys440'Dale]

Buck- we tore up and sown Jim's road this weekend and yes, Nick shut the quad off wide open. Still could not get the thing right. I really wish he would just take it back down to Treadway. The thing pops too, so just can't figure out what is wrong!

[buckeye400ex]

More I think about it, this sounds electrical, not jetting. Causing it to miss. ??? I dunno. Sent you an email too Jenny.

[SLB400EX]

JETTING SUCKS eehh Jenny.

Here are a few thoughts for ya girlfriend..
The VP gas might make plug reading harder. Have no experience with VP..but race gas will make plug reading hard.
We can't go by the plug reading's on Rob's either....

When's Nick's quad popping?? On the throttle or at decel? Decel..might have an exhaust leak. Hope it's that simple for him anyhow.

Right now, with a big ole hole in his air box, Rob's main jet is a 180(dyno jet) Stock pilot. Clip third notch down. He's running nice. (he cut out a 4.5"x6.5"-/+ section outta the top of his lid ..it's a big ole hole Jenny)
Now mine, with a big ole hole in air box lid....158 main(stock jets), 40 pilot, clip set 4th notch down. Just goes to show how these machines like different jet settings. lol. I'm just a smidge rich w/ the 158 but I'm gonna leave it in for the dunes...it'll be cooler up there, lean it out a bit.

(ha..I almost sound like I know what I'm talking about..scary huh??)

:devil

GOOD LUCK....when we were re-jetting Rob's we were about nuts thru the process.

[buckeye400ex]

Jenny, I missed the 100 octane piece. The plug is not as easy to read as our 400EX sista, SLB says. It's almost always white. I thought I read something about pump gas in there. ??

My suggestion.... Treadway! They've offered, and think about how much time you've spent on it already.

Come down on a Friday, stay at the house, get it fixed on Saturday, take it home running good.

[Jennys440'Dale]

Buck- Nick and I would be down, but we want to try and run Radar's up here and plus, I've already called Treadway and they want Nick's quad on a weekday, not a weekend. I wish Nick would take it down there!

Yea, Nick is running 100 LEADED. Sounds good if he cannot read the plug that well, but still need to find out what the popping is.

[SLB400EX]

Ok..you've done gone and made me think....happy now? lol.

two questions...
1..why are you re-jetting?? The holes a new thing?? More holes?? Huh?? Why? ;) What was his jetting b4?

2..have you tried a smaller main jet???? 185? or 180?? if so, does it run any better??

We rejetted Rob's to compensate for a larger opening in the lid. Had a 170 main(dynojet) in. Upped it to a 190. It didn't run bad really, but there was a noticable hesitation on the throttle. We were advised to drop the jet a size or two, did so to a 180 and the hesitation went bye bye.
Doing this to Rob's and learning a bit...the 190 sounds a bit high for Nick's...but then again, all quads are different.

Just trying to help..Hate to see ya bring it all the way down here...but I know Treadway will get the job done and save you two headaches.....

hhmmmm...good luck Jenny..

[SLB400EX]

Ahhhh, it is VP race gas he's running right?????
Straight, right?

Rob mixes half-n-half, 110 octane Torco with 93 octane pump gas....

[powerslider]

Sounds like your hitting the rev limiter, I think your to big on the main for what you have, start going down in size to see if it improves.

The 88R is the weapon of choice this trip, lets get some vibes going here for good weather ehh????