I adjust the idle to 1200rpm's and ride for a while. When I stop its back down to 900. I adjust it back to 1200 and a while later its back down again. Anyone else have this problem? How can I get it to stay up at 1200?

 

Try setting higher than you want and hope it settles into the rpm range your after. Sounds like the idle screw spring is weak and allowing the idle screw to vibrate out of position.