Well to make a long story short. Early 04 Sportsman 600. Pilot screw was bottomed out from the factory. Fixed that easily. Added Supertrapp Mudslinger exhaust, Dynojet kit, and K&N filter. Now start in single digit temps with no choke. At idle, it runs extremely rich (can't stand to set on it unless your moving). At 1/4 to 1/2 throttle it swithces to lean (head pipe glowing bright red and plug nice and white). The jet kit came with 132 through 148 main jets, and a new needle that ressembles a needle of a mid 80's honda. I've tried all differant combo's of jet's, needle setting, and pilot settings. I've even put the cold weather kit from polaris on it. No change. Oh yeah. The other thing I've notice is when I go easy from 1/4 to 1/2 throttle it falls on it's face but when I roll on fairly hard it's as smooth as can be. A real pain when trying to plow snow. Anyone else ever have a problem simerlar to this or am I missing something obvious.

 

It's no surprise that it runs rich at idle...........since you can start it in single digits without any choke is an indication that you're way too rich in the idle circuit. If you then go way lean in the midrange, I'd say that your needle clip position (if it has that) is too high and/or your main jet is too small.

Put the carb back to stock configuration and go from there.

I would think that the following would be fairly close:

1. Idle mixture screw out one turn from closed.
2. Jet needle set with clip in middle slot or one slot closer toward the bottom of the needle.
If needle is not adjustable, place a small washer under the needle's seat to raise it's position slightly.
3. Main jet two sizes larger than stock.

If the rest of your engine/ ignition/ etc. is running properly, this should definitely put you in the ballpark.

 

Thanks for the info. As of now, I've got the needle that came with the kit in on the bottom positon with a 165 main jet. MAJOR improvement. The pilot settings I still have to play with but at least the mid and upper has richend up. Thanks again

 

the piolet only is working up to 1/4 throttle most of the time so that wont effect the midrange. i also would like shep said raise the needle(lower the clip) at least one knotch to help the mid range lean condition.