Jetting Issues with 43f XT600
 

Quick description of issue: I have a supertrapp exhuast and air pod filters. I have fully cleaned the carb and rebuilt it.

I get a studder in throttle response around 4500rpm. I adjusted the fuel mixture screw to around 3 turns out and it runs better than if its the stock 2 turns out.

The weird part is im getting carbon builup on my exhaust. Running rich? But in order for it to run good it needs to be rich on the mixture screw... Any solutions. No hard starting or backfiring, idles great. Spark plug suggests possible slightly lean.

typical woes of deleting the airbox..... no easy solution. Supertrapps are also an odd system, they work by choking with the end plates, not first time i hear about issues with them
was the bike running right with these mods before? Or it all started after?

It had been running the same since I have gotten it. The supertrapp and air pods were already in place and I would like to keep them. I guess my best solution would be try different jet sizes and see what works best for the airflow. Also I believe the black smoke on the exhaust could also be oil burning off the top end and have nothing to do with the jetting. Im going to investigate further tomorrow.

you check jetting by reading the plug, put a fresh one, do some good undisturbed miles at WOT if possible. pull it out and that will tell you you are rich or lean on the main jet. once the main is sorted, mid throttle is more needle dependent. dont touch the needles until you have the right main.

problem with XT is that the CV side of the twin carbs doesnt like running without airbox. the slide carb side is easier to sort out.

Awesome thanks man! I actually just took it for a spin after adjusting the mixture screw out 3 turns. It works beautifully now. Seems I just didn't have it right for the pods.

Im going to rebuild the top end this winter as one of the lower gaskets is leaking some oil. Any suggestions for that job that I should know about?

just general things you normally need -
Service manual;
Proper tools including torque wrench, possibly couple special tools;
New parts (gaskets, seals etc, preferably a kit), oem or good quality ones (e.g. athena);
Readiness for doing rebuild further than planned (parts/time/money) according to condition you'll find there;
Good luck!

P.S. can't agree as far as I know burnt oil gives more bluish color to the smoke, rather than black.

Yes, black smoke is rich mixture, blue smoke is burning oil.

Thank you so much guys! Its my first dual sport although I have wrenched on old sportbikes and dirtbikes. Just not exactly the same as big thumper haha

Af 4500rpms youre still mostly using the needles. Try to raise the main needle a notch, perhaps both of them.