Re: riding downhill
I agree with what has been already stated. When you are going downhill just let off the throttle and pull the clutch. Then just engage when going back up. That's how I ride mine and have been for two years now. I would advise you change the chain to a #41 roll chain though. That chain from wally mart isn't very much better than the kit chain. You can get #41 roll chain from any Tractor Supply, Ace Hardware, or pretty much any hardware store. You will probably get twice as much chain as wally mart for about the same price.
Hope it Helps. I am also a proud member of the 20 MPH. club