Jetting help

R

richp

Member

Apr 26, 2004

19

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• Apr 26, 2004

• #1

I have a 94 kdx 200 that when I run with mix of 32:1 I kill every mosquito in a 5 mile radius. Not that I love mosquitos, but my wife is behind me on her XR and can't see a thing. The bike has aftermarket pipe and silencer that was put on by previous owner. What would be a good baseline jetting to get me started with? What premix ratio is preferred? Thanks.

 

R

rethnal

~SPONSOR~

Jul 14, 2002

659

0

• Apr 26, 2004

• #2

1989 to 1994 KDX200

Stock -Run the stock R1172N jet needle in the second from the top clip position, 48 pilot jet, 155 main jet and fine-tune the pilot circuit using the air screw.

With a performance pipe/expansion chamber, the air box lid removed and the stock or a performance silencer run a 45/48 pilot, R1173N jet needle in the mid clip position, a 152/155 main jet fine tune the pilot circuit using the air screw.

Depends on what oil you are using. Some Full synthetic can be used at 100:1 but I would never go there. 50:1 is the thinnest I would ever go with any oil. Check the recommendations on the bottle of oil you are using. I run 40:1 and works well for me. Mobil 1 MX2T and is $3.50 a pint at AutoZone, it gives a lot less smoke and is full synthetic.

 

J

JasonWho

Member

Apr 10, 2002

2,109

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• Apr 27, 2004

• #3

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Last edited: Sep 17, 2004

R

richp

Member

Apr 26, 2004

19

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• Apr 27, 2004

• Thread starter
• #4

I live in CT., about sea level. Been running Kawasaki oil. Ngk plugs, can't remember plug type but 9 heat range.

 

C

cicone

Member

Sep 29, 2003

310

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• Apr 27, 2004

• #5

Like Jason said--a clean air filter is a must(perhaps a Unifilter) as is clean silencer packing, clean carb, and clean pipe---air box lid off and spend a couple bucks on the Boyesen reeds. Check the threads for sealing your exhaust to the cylinder. It's a little cooler in NJ than here in N. Fl.--When the temps get down in the thirty to fifty degree range, I run a 40 pilot, cel 2nd clip, and 152 main. I have a 1990 and it screams with this combo---though judging by the A/S it's still a tad rich, but that's better than a bit lean---if you get my drift. :yeehaw:

 

C

cicone

Member

Sep 29, 2003

310

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• Apr 27, 2004

• #6

...on the plug issue. I'd say if you're on the pipe all the time the 9 heat range will work, but if you lug it a lot or spend most of your time under 7,000 RPM you might go to an 8---check the plug after the jetting is sorted out. If it's clean, fine. If not, go to the 8. I'm running 36:1 either Yamalube or Motul---it's easy to mix---pour 16 oz. in a 5 gallon can and add 4.5 gallons high test.

 

Last edited: Apr 28, 2004

J

JasonWho

Member

Apr 10, 2002

2,109

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• Apr 27, 2004

• #7

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Last edited: Sep 17, 2004

C

carney

Member

Mar 17, 2004

42

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• Apr 27, 2004

• #8

richp if you are nearby Hartford give me a shout, I'll probably be messing with the jetting on my '88 soon, which uses the same carb, and a similar range of jets. I know a good place for WOT testing too :)

 

R

richp

Member

Apr 26, 2004

19

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• Apr 28, 2004

• Thread starter
• #9

Got carb apart today (5:30 am) and this is what i have. 145 main,48 pilot and r1172n needle. Clip is second from bottom(stock?). Air screw was 2.5 turns out. Think I could get away with moving clip up and turning screw in?

 

J

JasonWho

Member

Apr 10, 2002

2,109

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• Apr 28, 2004

• #10

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Last edited: Sep 17, 2004

G

G. Gearloose

Pigment of ur imagination

Jul 24, 2000

709

0

• Apr 29, 2004

• #11

a 145 main is the product of somebody not knowing what they were doing, or trying to set the main with plug chops with the airbox lid and snorkle still in place and unmodified.
Will result in a lean, flat bog when wicked open until it revs up and creates enough vacuum in the airbox to richen it back up. Also tricks the tuner to keep the needle high to eliminate the bog, and so it runs fat at low rpm, small throttle, hence the smoke. No jet/needle combination can compensate for this rpm dependance until the airbox can breathe.

 

R

rethnal

~SPONSOR~

Jul 14, 2002

659

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• Apr 29, 2004

• #12

145 is WAY off....and 2 and a half turns is TOO much. 2 turns at the most or rejet to get it in the range. Start with the baseline jetting I gave you and adjust from there... It should be close from what you have given us..... Post your results!

 

R

richp

Member

Apr 26, 2004

19

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• May 2, 2004

• Thread starter
• #13

I moved needle one slot up and the screw 2 turns out and smoke is gone but now slight bog on quick throttle at low rpm's. Runs like a rocket up top. Any ideas? Running belray at 32:1 at sea level. 145 main, 48 pilot. Needle 3rd slot from top.

 

G

G. Gearloose

Pigment of ur imagination

Jul 24, 2000

709

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• May 2, 2004

• #14

Any ideas?

Click to expand...

None I can share... :think:

 

R

richp

Member

Apr 26, 2004

19

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• May 3, 2004

• Thread starter
• #15

One thing I forgot to mention is yesterday I removed the stock airbox lid after I changed the needle setting. Would that make that much of a difference?

 

K

KAY DEE EXER

~SPONSOR~

Mar 3, 2003

629

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• May 3, 2004

• #16

richp said:

One thing I forgot to mention is yesterday I removed the stock airbox lid after I changed the needle setting. Would that make that much of a difference?

Click to expand...

Yep. It should breathe better. :thumb:

 

G

G. Gearloose

Pigment of ur imagination

Jul 24, 2000

709

0

• May 3, 2004

• #17

richp said:

Would that make that much of a difference?

Click to expand...

Yes, opening the airbox, but leaving your main at a 145 will frag the top end. :ohmy:

Set your main jet to 150, 153, 155, 158 range with a WOT plug chop. Put in a 155 to start before WOT again.

 

J

JasonWho

Member

Apr 10, 2002

2,109

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• May 5, 2004

• #18

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Last edited: Sep 17, 2004

R

richp

Member

Apr 26, 2004

19

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• May 5, 2004

• Thread starter
• #19

This might sound like a fool question but if i read right, the air mixture screw goes rich as you screw it in? Everything I work on ,out is rich and in lean.

 

J

JasonWho

Member

Apr 10, 2002

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• May 5, 2004

• #20

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Last edited: Sep 17, 2004