Help!

[living_to_ride]

im having some serious issues with my chain and front sprocket. Earlier i jammed it up... BAD.... i broke a sprocket tooth. I replaced the sprocket but now it seems like every time i ride it something happens... it jammed twice today and now ive grinded out the shaft on it. Any ideas as to what could be causing this would be very much appreciated....

[underpowered]

swingarm bearing bad causing the chain to loosen up and tehn tighten as the swingarm moves back and forth. too much slack in teh chain, rear axle bearings bad causing same thing as bad swingarm bearings, kink in teh chain. could be a number of things, i would check each of those.