First post here. I had to rebuild carb cause gas float was stuck and gas was filling up in air box and gas leaking out of bottom of carb. And now it starts up but the ldle is really rough i tried adjusting the idle air mixture screw and no change in idle so I tried putting it in gear and see what it would do it bogs down and dies all the carb kit I used was for a 99-2000 sportsman only difference was the new main jet was a little smaller please help guys thanks.

 

Car kit is a good direction to go first,but I'd pull the cam cover and check the valve clearance and also for any signs of a worn exhaust lobe on the cam as the Magnum 500 and Sportsman 500 were basically the same engine.From 96-2000 soft cams were a problem. If the lobe is ground down usually they will idle ok,but wont accept throttle and many would just backfire. Vaves set at .006 intake and exhaust.Dirt Cheap Yamaha & Polaris OEM Parts & Accessories – Cycle Parts Warehouse Plus here's a cam from a 500 Scrambler that had the lobe worn down. Hope it's something simple like valve adjustment needed causing the problem you're having.Bad Cam Pic - ATVConnection.com ATV Enthusiast Community

 

. Thanks for taking the time to answer my question I'm going to check it out in the morning and again Thank you.