See this link for doing the VX, most steps should be the same: http://www.pwcforum.com/yamaha-jetsk...winterize.html
I think the big thing with carbs. on your 1200 is to be sure to run some stabilized fuel through the engine 1st. I use Stabil Marine. Then fog the carbs if it is possible. I can't remember how its done on the GP.............it might not be possible due to the location of the carbs. If you can't fog directly through the carbs, then I'd add a heavy dose of carb treatment to the fuel along with the stabilizer and run that through. I'd recommend Yamaha Ring Free Plus, but SeaFoam is another choice. This will help prevent your carbs from varnishing up when the fuel in them dries out. I'd also spray some fogging oil into each cylinder after you remove the plugs and spin the engine over a few times to distribute it. Here is a link with other tips for 2 strokes: Winterization Instructions
I lube the cables with a cable luber.