I'm having a bog on the bottom end of my 02 Summit 700. It has the TM 40-B163 carbs. It seems to be a rich bog as it gets worse as the sled motor warms up. It's clean if I snap it from the bottom, I'm just having a problem if I'm putting in tech terrain (as slow as sled can go) and then I give it some throttle. It has a good couple second bog then kicks in. It seems rich on the pilot as well because it likes to flood when starting hot, starts fine cold. It also seems to get a little bit worse at altitude, even with the dps....
So I figure this must be an air screw issue. I tried leaning it out, the idle came up, it started good hot, but the bog was still there, possibly worse?Carb and jets are clean. Do I try the needle? The bog is really only right at the bottom...

Also the manual seems weird on the air screw, clockwise to lean. I've always thought 2 strokes are air screws, meaning clockwise, closing, richens mixture, were as a 4 stroke fuel screw, closing leans....
It does lean out when you close it though.

I'm kind of lost here, jetted many bikes, but this sled....

Those carbs have a fuel screw instead of an air screw so your manual is correct, clockwise (in) is leaner.

I would put those back where they were and try dropping your needles one clip. If that doesn't help I'd suspect the DPM is the problem.

Ok thanks I'll try that.

Well it turns out the needle is non adjustable, one clip only. BUT when I pulled it I found the little plastic washer that is supposed to sit below the clip was above. So I placed the washer in proper position essentially raising the needle and voila, bog gone. Then I leaned the air screw a 1/4 turn. Now I have a sled that starts easy hot or cold and runs clean and strong with no bog anywhere. I also noticed the mid range was a little stronger.
So it was to lean in the end!!

This was my wifes sled, we've had it since new and it's always had that irritating bog. It hasn't gotten ridden alot in past years so I never got around to tuning it. So obviously on dealer setup the washer was installed wrong.
I can't believe I waited all this time to get a manual and some help from here to work it out

Anyways it runs great now

good to hear