What is the proper chain slack?
There should be 2″ of play (pushing up and down) center-to-center, midway between the sprockets. The ultimate test is to compress the rear suspension as much as possible (ideally, engine output shaft, swingarm pivot and rear axle in a straight line), and see if the chain gets too tight. You can use tiedown straps to pull down the rear, or use your weight. This can be done by folding yourself over the seat from the right side, placing a wrench on the rear axle nut, and then pulling up on the wrench with your left hand (like you’re trying to tighten the nut). This should give you good compression. Check the chain for slack with your right hand.
