I'm not familiar with diagnosing carburation, or anything for that matter, but i like to learn by doing. So when my quad dies going downhill at idle it gives me a reason to tear it apart and learn. It idles a bit rough and also a bit cold blooded on start up, but revs good. On another note I have a stage 2 dyno jet kit and plan on upgrading from a modded airbox to a open setup(sixsixT or Prodesign). I only run on dunes at the oregon coast and was wondering what would be the best setup for my riding and if setting up my jetting would eliminate my dying downhiller. [img]i/expressions/face-icon-small-confused.gif[/img]

 

The float level may be high but most people have a problem going uphill. Do a search on adjusting it using the clear tube method, it will only take a few minutes to check it that way to see if that might be your problem.

 

The running rough, dies pointed downhill and cold blooded...al point to a lean condition. I agree with checking the float level, it may be too low. Also check for intake leaks.
Be aware if you take the air box lid off, itll lean things even more.
You could try redoing the mixture screw adjustment, and make it slightly more rich. If you get to 4 turns out from lightly seated, and its still not enough...youll need to go bigger on the pilot jet.
Heres a good article on jetting and carb dianosing.
click here

 

Turn up your idle, install 25 pilot jets if you havent already. And of course check the floats.

 

Thanks guys for the input. I was leaning towards the floats but with my experience it would have been a shot in the dark. I checked out the clear tube method and it seems pretty easy, so I'll run a test when I get a chance. Thanx again