When it is below 32 degrees, and I go riding, my Banshee does not run very well.I know it is not a jetting problem.When it is above 32 degrees the quad runs great, it loses power and sounds different when it gets cold.

I have a 2000 Banshee with a Dynport 2into 1 pipe ,K@N Filter, and some slight airbox mods.

Has anyone had this problem before, or know anything about it??

 

I know that you have stated that you do not have a jetting problem..... But temperature does make a quite big difference.
Because of the density of the air with temp changes it is often necessary to change the jetting to compensate.
I know that I had to go up a size on my main jet when I intalled my pro-flow kit w/k&n. and I did not even vent the Box...I just removed the snorkle. The K&N breaths much better than the stock foam filter. which could lead to a lean running engine.
Just an idea...
Good luck
~Jim

 

The stock Banshee runs great under 32 degrees. No reason why a modified one shouldn't. Although they do recommend a higher main jet and turning the air screw in some for conditions this cold.

Some guys around here race on ice. They make jetting mods to keep the bike from running to lean. You may want to revisit the jetting issue.