how the heck to adjust kdx220 chain

It's really simple. Loosen the nut in the right side of the axle. There is a snail adjuster on each side of the axle with a roll pin that needs to be in the same numbered notch on each side. Put weight on the seat until the swingarm is parallel to the ground and make sure the chain still has a little slack.

Put bike on crate or similar to lift up, Loosen rear axle nut, adjust chain tensioners to required slack, tighten rear axle nut to 72lbs. Take bike off crate or similar lift.
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