I have a 2009 sportsman 500 HO. Runs fine with 1 person. But it seems if you have someone over 250lbs it's bogs down and doesn't want to run. Or if you have a passenger it bogs down. If they stand up or get off it's runs fine. I've looked for pinched vent hoses and electrical wires nothing seems wrong. Air filter is clean. Getting good spark. Could this possibly be a cam shaft issue? Getting worn down? Will idle fine with passenger sitting on it, second you give throttle it bogs like it's getting to much fuel and no air.

Thanks.

 

Think I'd be looking at the belt and the clutches. Belt stretch,possibly worn parts especially in the driven clutch. May be able to work fine for a lighter operator,but belt can slip,lose power under a load. If this checks out might be time to check into a carb kit and clean the carb. Cams weren't a problem on these later model 500s.

 

I just checked the belt and it had quite a bit of play. I could probably pull it off with my hands, and some of the teeth are worn down on the sides. With these atv belts should they be tight like any belt driven motor at rest? Belt easily changed? Can I do it by only taking off rear pulley?

 

The belt can can be changed easily without taking the pulley off. It's easier to do than it is to explain but you have to roll the belt over the edge of the pulley.

 

Just pull up on the middle of the belt and roll it off the rear clutch.Have it in an open area and blow out all the loose belt dust.Cheap carb or contact cleaner can get rid of any caked on dust and dirt. Get the oem Polaris belt as it's the best. If this is the original belt,you've got your money's worth out of it.