moosecat, i knew youd get it. Sounds like youre a pro already.
Id try a pilot jet, thats one up(next size bigger). Some times the enrichener, is just tightened at the carb, and adjusted at the ****.Sometimes all you can do, is look at the rubber piece, that goes in the carb, for nicks or pieces missing, or worn areas. Then with it out of the carb,check that the **** actually moves it enough.Theres a separate starter jet, in the carb , that adds fuel, when the enrichener is lifted up. So going bigger on the pilot jet, does much the same thing.

 

found some more web sites on jetting, if youre interested.
http://www.smellofdeath.com/lloydy/jetting.htm
http://www.motocross.com/motoprof/mo...1/carb101.html
http://www.4strokes.com/tech/howtojet.asp

 

Thanks again, Hondabuster, don't know what I'd done without you guys this
weekend, thanks for the sites, I'll check em out and try it.
The cat's running great, but bad cold natured.

 

I'm surprised no buddy asked if you have done a compression check. I've seen problems at idle caused by a compression problem, but when you spool up the motor it doesn't have time to leak enough to cause you a problem that you will notice. By the way I really dislike diaphgam carbs, but for changing altitude like you can sometimes on a quads need them to run everywhere better.

 

Moosecat;

I have a 2000 AC 300. I had a lot of trouble with it fouling plugs, stalling etc. when it was new. Took it to 3 dealers to get it fixed. Here are my carb settings.

Pilot Jet 45
Main jet 135
E-Clip set on position # 2.

I would try a combination of adjusting the e-clip with different jets. I have read lots on this forum about adjusting the valves, but that is seldom the cause of the rough idle. Just experiment and find the combination that works for you.
These bikes are notorius for this problem. They are warm blooded motors. Funny that you never hear of the Suzuki King Quad having this problem. Good luck with your bike!