I just finished a winter long project on my 06 XL 1200. Some of the many things i did was upgrade to a performance ignition box, replace the hyper charger with a heavy breather and installed a SE Thunder jet kit ( which completely rejetted the carb ). I set the fuel/air mixture screw to the recommended setting 3.5 turns out but i have excessive carbon build-up on the chrome parts on the rear of my bike after a ride of 20 miles or more and if you open the throttle to about half open you can see the carbon coming out.

I live in eastern NC and i believe we are about 150 ft above sea level. This issue is very annoying since i just put chrome pulley on the rear. Also I have short shots on there now to explain my full intake/exhaust setup.

 

I turned the screw out just a hair over 2 times. I also have a chrome pulley and chrome swing arm. It does get "soot" on them. I just clean them a lot.

 

All the carb guys say 2 turns on the screw

 

That's where mine is, just a little more than two turns out. Not quite two and a quarter.

 

You have the idle screw way to far out 2-2.5 is all it takes. Those Thunder slid kits can cause more trouble than they cure sometimes.
Did you put in a 45 idle jet and a 180 main and I hope you didn't put that spring in the vacaum piston, those can cause of a lot of the over rich problems, they hunt which means they can make the vacaum piston move up and down way more than they are suppose to which in turn causes the engine to get way more fuel than it needs.

 

well the kit was a SE kit made by dyno jet. The Kit i used is the SE 29045-97B and the parts i installed were:

DET001 EMULSION TUBE
DNO855 FUEL JET NEEDLE
DW 001 SPACING WASHERS
DJ 170 MAIN JET
DSP009 SLIDE SPRING
THNOZ2 THUNDER NOZZLE

I drilled the slide lift hole using the #29 bit, removed the idle mixture plug and adjusted to 3.5 turns out and left the stock pilot
jet. I also repolished the slide and replaced the stock plastic carberator top and installed a chrome one. I also cleaned the carb in and out.

I could really use some guidance here. I'm going to take the plugs out tomorrow and look at them. I replaced them during the work I was doing and I think they have 100 miles on them. Any suggestions.




What would your recommendations be?

 

For starters,

What size Pilot jet is installed?
Which notch did you install the needle clip on?
At 3.5 turns out on the mixture screw, you either have it set too rich, or your pilot jet is too small.
The pilot jet should be a #45.

When I Googled the part # for the kit you have, the first page that came up carries this warning:
Important!-Do Not Drill Out The Slide Vacuum Hole Larger Than .125"! The Kit includes a #29 Drill (.138). It is too large, and can cause stumbling when throttle position is slightly opened.

 

well the pilot jet is the stock size. The kit didn't recommend changing it so I am going to assume it is a 45. I used the 3rd notch with the washers. As far as stumbling, i havent seen this issue yet. It runs rough when it is first cranks but it cleans up rather quickly. With this kit, what is the minimum you would recommend for the mixture screw?

 

This web site will help you tune your carb.


READ THIS PAGE.
Harley Davidson Carburetor
Performance Tuning

 

The stock on an '06 is 42

Here on the instructions I received from Keihin when I purchased their Jet Kit in '06. Agree / Disagree?