I have an 02 sportsman 700 which I upgraded the ignition on many years ago. This was a fantastic upgrade and it will now start amazingly quick. I was in a little hurry to retrieve a deer yesterday and drove over a large rock I've crossed many times with a slight belly bump and no issue.
I was driving a little faster than normal and after the bump to the bottom of the frame the engine immediately started popping and sputtering. I had to leave it in the woods for now.
I have noticed others mention carb boot and exhaust gasket as items to test regarding bad performance.
Anything else to take with me?

 

You may have knocked something loose. Anything from a wire connection to loosening a carb or intake manifold. Some very carefull and thorough checking is in order ....good luck!