Fuel stabilizer does help, but it won't keep gas from evaporating, you should be draining the carb's every time you put it away. Also I don't believe in fixes in a can like sea foam.... try soaking a dirty carb/gummed piolet jet in it, it does little. What I do like for off the shelf products is Yamaha combustion chamber cleaner in the aerosol can. I usualy tear the carb down, and soak the clogged jets ect ect in the carb float bowl(ie fill it up), this cleans out the bowl and the jet's at the same time, blow off/out with compressed air and its nearly like new.
I have been doing a little work on quad's ect this spring and had allot of stuck needles, but everything else was cleanish, but last year I had allot of green/brown carb's... but not many needles stuck.
I'm picking up a 2004 rx warrior this weekend, this is my first sled that I will have owned. I wanted a newer phazer but I am 6'3" and 240lbs and it just doesn't have quite enough power. I'ts definatley going to be easyer to remove and adjust the carbs and valves complared to the r1/r6 by the looks of it.