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Confused after a needle change...

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Hello all...

I am rather new to the jetting scene, but am willing to learn. I have done the Burger King mod and discovered that I needed to richen up my jetting. Especially on the bottom (top seemed fine).

I went from a 42 pilot to a 45 and did not mess with the fuel screw. I also lowered the clip one notch. The bike seemed to run ok on the bottom end. Pretty snappy. Then I ordered an EKN needle ( I was running stock). I put the EKN in with the clip in the 5th from the top, which is the same place the clip was for the stock one.

Now the bike seems to be fat on the bottom. Is this right? Will this needle have that effect?

Should I move the clip back up to the 4th spot or change out the pilot jet back to the 42?

Any help would be appreciated.


PS. I can get the needle changed in about 10 minutes, but the pilot jet will take about 30.

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I have similar symptoms with similar jetting but I have been waiting for some jets to come in. I am going to go from a 45PJ to a 42 first and then a 40 to see whether this leans out the bottom end. I will also raise the clip a few positions. I should have the results by the weekend.

I love the top end at the moment so when the I sort out the bottom, look out!

I see Taffy uses a 38PJ so it might be worth a try. He and others might be of more assistance than what I am as well.


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You appear to be very rich on the bottom end (0 - 1/8 throttle) with the 45PJ/75PAJ/__N needle. I recommend you put your 42PJ back in and go up on the straight diameter of the needle a bit...like to a P or Q. I monkeyed around for a bit with the 45PJ and had no success whatsoever...regardless of what PAJ I was using with it.

A good start I've found for us CO boys (roughly the same altitude I think...5K - 9K) is the following:

42PJ/75PAJ/1.5 turns Pilot screw/EKQ#3/160 main/200 MAJ. Start from there and make adjustments as necessary...

--Just realized I need to change my sig...so ignore the jetting settings down there...they sucked!--

As I understand it, the PJ, PAJ, and needle straight diameter affect 0 - 1/8 throttle...the jet needle clip position is only affecting 1/4 - 3/4 throttle...and your main jet is affecting as far down as 1/8 throttle - WOT. Reference this for a more detailed explanation of how to jet your bike...

Patrick Burns Keihin Carb Tuning Manual

[ November 15, 2001: Message edited by: LarryCO ]

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