KDXRIDER.NET

juliend wrote:

moto_psycho wrote:i really doubt its the fuel, 2-stroke mixes very well in petrol and the second its mixed it never seperates. id imagine the problem is probably carb flooding/splash

Do what? Your information is not correct. 2 stroke oil, especially castor based oils, are quite prone to separation. Not saying I think fuel is at fault in this case... just saying.

+1

juliend wrote:Agreed. At 3.5 - 4 turns you are probably a couple sizes to large on the pilot. If the pilot is that rich, it is likely that the main is as well. Follow the rest of the jetting guide.

I was suggested 155 Main and 42 Pilot, I'm currently running 152 Main and 48 Pilot. 155 is a bit rich I've been told, but is it a significant difference from a 152? You're definitely right about the pilot being too large

Just went to the shop today and picked up a 155 and 160 main jets, but didn't have anything below a 48 pilot jet besides a 40 (which the manager gave to me for free!) it's about 3mm shorter in length than the previous pilot jet that was installed, but he said it should be fine if it's still below the fuel level in the float bowl. He also said a 40 should be fine if I'm installing a larger main jet, lets hope this works

KDXrider1989 wrote:He also said a 40 should be fine if I'm installing a larger main jet, lets hope this works

A 40 seems really lean, and that statement from the shop is not correct; that dude doesn't know how to PROPERLY jet a bike.
The main is mostly on from 3/4 to full throttle, if your pilot is too lean, having a bigger main isn't gonna do anything from close to half throttle and you could still have a seizure I think.
I'm no expert but the tutorial explains it far better so I'd read it again.
http://www.kdxrider.net/forums/viewtopic.php?t=1156

KDXrider1989 wrote:

juliend wrote:Agreed. At 3.5 - 4 turns you are probably a couple sizes to large on the pilot. If the pilot is that rich, it is likely that the main is as well. Follow the rest of the jetting guide.

I was suggested 155 Main and 42 Pilot, I'm currently running 152 Main and 48 Pilot. 155 is a bit rich I've been told, but is it a significant difference from a 152? You're definitely right about the pilot being too large

KDX
What bike ? what temps ? what elevation ?
Your jetting seems pretty screwy in terms of your main being a 152
and the pilot at 48.
The main seems lean in comparison to the FAT pilot.
Don't need the choke off cold start do you ?

TWMOODY wrote:

KDXrider1989 wrote:

juliend wrote:Agreed. At 3.5 - 4 turns you are probably a couple sizes to large on the pilot. If the pilot is that rich, it is likely that the main is as well. Follow the rest of the jetting guide.

I was suggested 155 Main and 42 Pilot, I'm currently running 152 Main and 48 Pilot. 155 is a bit rich I've been told, but is it a significant difference from a 152? You're definitely right about the pilot being too large

KDX
What bike ? what temps ? what elevation ?
Your jetting seems pretty screwy in terms of your main being a 152
and the pilot at 48.
The main seems lean in comparison to the FAT pilot.
Don't need the choke off cold start do you ?

Bike- '89 KDX 200, Mods- full FMF exhaust, UNI air filter, power reeds, Temp.- mid 80's to upper 90's, Elevation- sea level to 500 ft. , and you're correct about never having to use the choke. A lean main jet would seem accurate considering how flat the powerband is from midrange to full throttle. I got the #40 pilot jet for free so at least I could say I never wasted $5

I would start that at a 155/45 combo and work your way down.
The 40 pilot you got for free you can more than likely pitch as
it will be to lean causing a bog on fast WOT.

What position is the clip in on the needle?

I would guess you will find your magic spot somewhere in the
155/152 main and 45/42 pilot

Awesome, thanks

Would turning out the air screw with the 48 pilot help lean the mixture a bit? I don't have a 45 or 42 pilot jet at the moment. Or lowering the needle? I believe it's set in the 2nd or 3rd position, I'll have to look at it again

If you are out 3.5-4 turns yes that leans it out however I would be more inclined to raise the clip on the needle a notch or two temporarily until
you get a smaller pilot.

Sweet, thanks again

I love this site

no problem

Solid advice here. 152/155 and 42/45 sounds about right to me as well. You'll need to test that though. Taking someones advice on jets and just running with it is never a good move. Every bike is different, and if you get too lean....

Aside from it just being too lean, that 40 pilot being shorter also would make me not want to use it. You can get a few jets from jetsrus or psep.biz for pretty cheap. My bike likes a 40 pilot, but that is with a CGK needle.

This is an E series bike? What are the chances he has a broken sub-valve?

That was suggested on page 1. His valves seem to be working.

juliend wrote:Solid advice here. 152/155 and 42/45 sounds about right to me as well. You'll need to test that though. Taking someones advice on jets and just running with it is never a good move. Every bike is different, and if you get too lean....

Aside from it just being too lean, that 40 pilot being shorter also would make me not want to use it. You can get a few jets from jetsrus or psep.biz for pretty cheap. My bike likes a 40 pilot, but that is with a CGK needle.

I'm aware of that, but having a good starting point helps. Now that I know my pilot is a little too rich, I'll probably just lower the needle or turn out the air screw until I can get the 45 and 42 sometime this week. I guess having the 48 pilot wouldn't hurt at the moment, it being rich rather than lean

Sounds good.

Well I finally installed the 155 main jet today, but left the pilot at 48 and didn't re-position the needle (I forgot to even check what setting its at) turns out the idle is fastest at 2 turns out instead of 3 1/2, I guess I went through the procedure too fast previously or maybe a I had an air leak somewhere. But whatever it was, it runs good now - very good. The over-rev is nice and the powerband is nice and clean from midrange to full throttle. I had a little bit of trouble trying to hang onto the bike at first

I couldn't thank you guys enough, I'd probably still be searching the internet and looking for advice elsewhere if it weren't for this site

I have a 38 pilot in my bike. Mind you, I'm at 4000'

You're riding a 220, right nick? Apples and oranges.

I'm running a 38, but I'm RB'd