So I was playing around in a flooded stream bed and got hungup on a stump, high centered, because I didn't see it below the water. Finally got pulled off of it, drove home and had a new rattle that sounds like the lower part of the right side. Almost near your ankle height. I looked around and could really only see where the exhaust pipe started was very close to the frame. Did I bend that into the frame? Any thoughts? Obviously I'm far from a mechanic!

 

just start feeling/looking for 2 contact points that would rubbing together. I would think if the exhaust was rubbing that at differnt rpms the sound would change to be abe to pin point it.

 

Don't know if this is your model,but just look at the exhaust shields,inner and outer,springs and the mounts. Several different place on the 800 that could rattle,if it's exhaust related. Dirt Cheap Yamaha, Honda, Arctic Cat & Polaris OEM Parts & Accessories – Cycle Parts Warehouse

 

i think if i remember right my 06' rattled from the heat shield, but the 08' has differnt shields.