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Needle Jet Help!


jayzx10r

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So my Banshee jetting is too fat (rich) at 1/4-3/4 throttle position. The tech document from Keihin isn't exactly straight forward to me...maybe someone can help me decipher the info.

I don't need another piston like the one in my avatar. :blink:

 

33mm PWK's on a dune port 4 mil. Glamis use only.

I'm running OK on my main. A 150 was too lean at night but the 152 is good at 300'ASL.

Can't remember if I'm running a 48 or 45 pilot.

Needle is a CEL with clip on #1 position (top/leanest) and my pipes spit oil and the plugs are black.

 

From Sudco/Keihin: http://www.sudco.com/vol33/135-136.pdf

 

Looking at this graph right side it seems the direction I need to follow is up...the direction for leaning out my problem area.

The thing is, the left side of the same page shows lean = down...opposite the info on the right side of the page!!

 

Since I'm at the #1 clip position on a CEL, shouldn't I get a BGL needle and try that??

 

:thanks: for your help...

 

Jay from SanD.

Edited by jayzx750
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So my Banshee jetting is too fat (rich) at 1/4-3/4 throttle position. The tech document from Keihin isn't exactly straight forward to me...maybe someone can help me decipher the info.

I don't need another piston like the one in my avatar. :blink:

 

33mm PWK's on a dune port 4 mil. Glamis use only.

I'm running OK on my main. A 150 was too lean at night but the 152 is good at 300'ASL.

Can't remember if I'm running a 48 or 45 pilot.

Needle is a CEL with clip on #1 position (top/leanest) and my pipes spit oil and the plugs are black.

 

From Sudco/Keihin: http://www.sudco.com/vol33/135-136.pdf

 

Looking at this graph right side it seems the direction I need to follow is up...the direction for leaning out my problem area.

The thing is, the left side of the same page shows lean = down...opposite the info on the right side of the page!!

 

Since I'm at the #1 clip position on a CEL, shouldn't I get a BGL needle and try that??

 

:thanks: for your help...

 

Jay from SanD.

 

I would try the CGL's it is the same taper and diameter just longer. I believe pwk33's come with cgl's from keihin.

 

Here is a good keihin tech article

http://www.duncanracing.com/techfaq/Tech_k...n-jetting.phtml

 

josh

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I would try the CGL's it is the same taper and diameter just longer. I believe pwk33's come with cgl's from keihin.

 

Here is a good keihin tech article

http://www.duncanracing.com/techfaq/Tech_k...n-jetting.phtml

 

josh

CGL is the needle I would try next as well. Had some jetting issues with another 421 cub with 35PWKs and just could not get it right with a CEL, switched to a CGL and it cleaned it right up...

 

That duncan article is a good one. :thumbsup:

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CGL is the needle I would try next as well. Had some jetting issues with another 421 cub with 35PWKs and just could not get it right with a CEL, switched to a CGL and it cleaned it right up...

 

That duncan article is a good one. :thumbsup:

Is the BEL the next step leaner after the CGL?

I was thinking that since I'm on clip position #1 on my CEL, I'd want to jump 2 steps.

Someone told me that 1 needle jump = 3 clip positions. Maybe BS though... :blink:

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Ok I'm going through the same thing. The first letter is for the taper, taper controls the transfer from the needle to the main. The second letter is the length of the needle which controls a majority of the mid range. The last letter is the diameter of the needle which controls the transfer from the bottom into the mid.

If you have the CEL go with the CGL. Thats one size leaner in the length which is what your looking for.

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Changing the diameter wont solve his problem. He is rich from 1/4 to 3/4 throttle. Diameter only comes in to play in the 1/4 range. He is out of adjustment since he has the clip in position #1. So he needs to put a longer needle.

Yes, you are correct, I had it switched. :thanks: The next leaner needle after the CGL is the BEL, which is a change in taper (unless I am still screwing up the chart :whistling:).

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Yes, you are correct, I had it switched. :thanks: The next leaner needle after the CGL is the BEL, which is a change in taper (unless I am still screwing up the chart :whistling:).

 

I dont know if I would say it is leaner. The B is going to be leaner in transision from 3/4 to wot due to the taper of the needle. But it is a shorter needle so it will be richer from 1/4 to 3/4 throttle.

 

First letter is taper wich is controls the transision from 3/4 to wot.

 

Middle letter is length wich has has the broadest affect. 1/4 to 3/4. You switch the lenght it makes a change over the whole needle range.

 

Last letter is the diameter wich controls the transision from the pilot circuit to 1/4 throttle.

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I dont know if I would say it is leaner. The B is going to be leaner in transision from 3/4 to wot due to the taper of the needle. But it is a shorter needle so it will be richer from 1/4 to 3/4 throttle.

 

First letter is taper wich is controls the transision from 3/4 to wot.

 

Middle letter is length wich has has the broadest affect. 1/4 to 3/4. You switch the lenght it makes a change over the whole needle range.

 

Last letter is the diameter wich controls the transision from the pilot circuit to 1/4 throttle.

I do agree that he needs a longer needle...

 

He says his CEL is too rich, and let's suppose his CGL is too rich also (I really think the CGL will be good). According to the needle chart, a G length needle is the longest. Where should he go next? According to the needle chart, the next block of needles leaner than the C_L needles is the B_L needles. Maybe there are longer C_L needles available that are not listed... :confused:

 

Keihin needle chart

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I do agree that he needs a longer needle...

 

He says his CEL is too rich, and let's suppose his CGL is too rich also (I really think the CGL will be good). According to the needle chart, a G length needle is the longest. Where should he go next? According to the needle chart, the next block of needles leaner than the C_L needles is the B_L needles. Maybe there are longer C_L needles available that are not listed... :confused:

 

Keihin needle chart

 

That I couldnt tell you. If the cgl's were still to rich from 1/4 to 3/4 throttle and since you cant get a longer needle I would probably start out by going with a leaner taper (B) E length and K or J diameter. Then if I ran out of clip positions then I would go to a G lenght needle.

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