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With all things being equal - would changing the needle shape (to a CEL from stock) affect the jetting sizes?

When I changed my needle I did not have to adjust any other jetting

Actually, yes, most likely. CEL has an overall richer profile, so you would likely need to step down a bit on pilot and main. Doing that will actually lean it out over stock pretty dramatically at about 1/4 throttle, while maintaining a pretty similar fuel mix at WOT. This image shows the needle profile and fuel mixture difference when moving from BGN to CEL. Your results may vary.

There's good info here, as well:
http://www.kdxrider.net/forums/viewtopi ... 105&t=3263

Julien D wrote:Actually, yes, most likely. CEL has an overall richer profile, so you would likely need to step down a bit on pilot and main. Doing that will actually lean it out over stock pretty dramatically at about 1/4 throttle, while maintaining a pretty similar fuel mix at WOT. This image shows the needle profile and fuel mixture difference when moving from BGN to CEL. Your results may vary.

There's good info here, as well:
http://www.kdxrider.net/forums/viewtopi ... 105&t=3263

bgnVcel.PNG

Interesting, Mine must've been a bit lean a when I swapped needles

In my experience the pilot and main jets both have been affected by a needle change. When my pilot is set up for the JD red needle and I reinstall the stock 220 needle (both on the 2nd clip) its so lean that I cant even touch the throttle without it dying. Its the opposite on JD red vs DEK, its too rich with the DEK. JD red vs CEL are both good on my bike with a 40 pilot. One of the guys at JD told me its not uncommon to need a main jet that's 2-3 sizes smaller with a JD needle that you were running with a Keihin needle. I wouldn't be surprised if you change the needle and then need to restart the jetting guide from the beginning.

Good to hear because I thought I was doing something wrong. With the CEL needle my bog off idle went away, but now I am fouling plugs to failure in a couple hours.

The 40 pilot is now at 3 screws out (KDX220 basically stock with a pipe) so gonna start the jetting guide over with a 38 pilot and see where that leads. And also will likely be dropping from 148 main back down a step or two (bought 145, 142, 140 mains to have on hand)

straight diameter on the needle and pilot jet size are linked. with a CEK needle i had to go down to a 32 pilot

Using my 46:1 premix (golden spectre oil) I found that my KDX 220 likes the size 38 pilot jet the best, at 1-1/4 turns out. Float at 18mm
Also using the CEL needle with clip 2nd down from top

So now on to the MAIN jet.
Tried a 145 main and did two plug chop runs slightly uphill (plug on the right)
Then tried a 142 main with a new plug and did one slightly shorter flat run (plug on the left).
[Wish I could have done better tests, but at high speed along power lines started bouncing around and thought I was gonna die !]

*Cutting open the plug to expose the base on the insulator thing was VERY different than just looking from the top !!

Looks like the plug on the left (142) has more of a tan/brown color starting, while plug on the right (145) has jet black soot color.

If i might ask, what are the benefits of changing out the stock needle on a stock KDX200 (04)

It looks like the plug chop on the left didn't come out right. The 145 looks like a good plug chop, good to read but too rich. Without driving really far away I don't have the room (or smooth enough run) to go into 5th or 6th. What's worked for me is to run 1st - 3rd or 4th full throttle, pull in the clutch but don't kill the engine, turn around and head back the other way, this time killing the engine. You could do 3 or 4 of those passes and then kill the engine. You're either wide open or just off idle turning around. The very top of your plug is the only thing that would get any color from idling for that short time and won't affect the mixture ring you're looking at. When that black ring is half the thickness and coffee with creamer colored the power felt is going to be worth the trouble. It makes a big difference in how many rpms your bike will pull to and how strong it feels coming onto the main jet.

John_S wrote:...the power felt is going to be worth the trouble. It makes a big difference in how many rpms your bike will pull to and how strong it feels coming onto the main jet.

I completely agree! Proper jetting just adds more power throughout the rpm range. How much depends on how far off it is to begin with.

firsthere... my KDX2220 has a different carb than the 200. But in the 220 changing the carb needle leveled out some problems in the medium range.

SS109 wrote:

John_S wrote:...the power felt is going to be worth the trouble. It makes a big difference in how many rpms your bike will pull to and how strong it feels coming onto the main jet.

I completely agree! Proper jetting just adds more power throughout the rpm range. How much depends on how far off it is to begin with.

and to play devil's advocate...

Improper jetting actually takes away power that is SUPPOSED to be there. It presents as "less than intended".

BamBam wrote:Good to hear because I thought I was doing something wrong. With the CEL needle my bog off idle went away, but now I am fouling plugs to failure in a couple hours.

The 40 pilot is now at 3 screws out (KDX220 basically stock with a pipe) so gonna start the jetting guide over with a 38 pilot and see where that leads. And also will likely be dropping from 148 main back down a step or two (bought 145, 142, 140 mains to have on hand)

I'm right there with you, bog when running out of steam on steep uphill trails. 40 pilot, 3 out, stock pipe and needle though. I have a 38 ready to install.

My bike had a very pronounced bog when snapping the throttle off idle.
I replaced the jet block gasket, measured the float to 18mm, and installed a CEL needle. Then jetted to the 38 pilot. Bog is GONE! Night and day difference. So sharp and immediate to the throttle touch now, hope a sneeze doesn't cause me to fly off the trail and wreck. Ha!

Sounds great! which CEL needle? Only off item, my floats are raised just enough to keep from pissing while on the kick stand. Maybe not at specs. And Stock pipe.

For the KDX 220, this is the CEL needle I read about here that worked so well.... https://www.jetsrus.com/individual_part ... 17_su.html

And I don't know how to 'test' to see if you have a bad jet block gasket, but its a pretty cheap and simple fix that solves a lot of mysterious carb problems. Worth doing if you are ever have the carb on a bench and mucking around.... https://www.jetsrus.com/individual_part ... 32_su.html

Jason wrote:and to play devil's advocate...

Improper jetting actually takes away power that is SUPPOSED to be there. It presents as "less than intended".

To play devil's advocate myself, Kawasaki jetted it like crap from the factory so it obviously wasn't meant to have that power!

BamBam wrote:And I don't know how to 'test' to see if you have a bad jet block gasket,

Now you know! BTW, you don't need compressed air. You can use the pressure from your mouth blowing to achieve the same thing. Another member posted recently on that.

[youtube][/youtube]

BamBam wrote:For the KDX 220, this is the CEL needle I read about here that worked so well.... https://www.jetsrus.com/individual_part ... 17_su.html

And I don't know how to 'test' to see if you have a bad jet block gasket, but its a pretty cheap and simple fix that solves a lot of mysterious carb problems. Worth doing if you are ever have the carb on a bench and mucking around.... https://www.jetsrus.com/individual_part ... 32_su.html

Thanks, I'll change the jet block gasket for sure.

Do you recall which way the the fuel mixture changed with the CEL needle? Was your 220 running rich or lean down low. I'm thinking my 200 is too rich off idle? BTW: running power reeds but same situation with stock reeds.

The guys here have tons of info. While the CEL made it richer in the mid, it also leveled out some problems in the stock fuel curve. I went second clip down from top top combined with smaller pilot and main jet. Wonderful !