How to tightin a chain on a 660 rator ATV?

Answer 1

The very rear of the swingarm are 2 bolts.
They're pinch bolts. They pinch the swing arm around the bearing holder to prevent it from turning.
Going through the swing arm is the bearing holder.
The bearing holder is shaped like an oval.
When it's turned, the axle moves forward or back, which loosens or tightens the chain.
Loosen the pinch bolts and turn the bearing holder.
Make sure you adjust the chain to the correct chain slack specs.