I got an 01' warrior 350. Bought it in the winter around February. The thing ran like a champ all winter and beginning of spring. I changed the clutch, oil and filter about 2 months ago and have had throttle problems since. I've searched the Internet for weeks to no avail. I also changed the plug and cleaned the carb. What it's doing is about 1/2 throttle and WOT it sputters and loses power around when the power band kicks in. But cruises fine around 1/4 throttle. Checked and cleaned the air filter as well. I disconnected the parking brake switch and it seemed to run a little better. Any ideas???????

 

Sounds like your main jet has some trash in it

 

How does one go about cleaning the main jet? I tore the carb apart as much as I could and cleaned all the cracks and crevis' of it. I'm an auto mechanic and not much of an atv mechanic lol. I couldn't figure out where the jets were in the carb or how to remove them.

 

just take the bowl off and the jets are the brass pieces. one is the main jet and the small one is the pilot jet. unscrew them with a flathead screwdriver and look through them. you'll probably see some gunk in the main jet. the holes are tiny so it doesn't take much to stop them up. Blow some carb cleaner or compressed air through them until they're all clean and reinstall.