I dont think the old gas gums up the carbs. As the gas dries it leaves a glaze or film on everything, thats the trouble. If you run your sled every month you keep the carb bowls filled with gas and thus avoid the glazing. Park it for the summer the bowls dry once and you get 1 layer of glazing...
My last sled was a 163, and i moved back to a 154 this year. It all depends on snow conditions. If its deep powder 163 is the choice. If you get alot of windswept, spring riding, trail, wet snow, then 154 works just ass well or better. I loved the 163 in what i called "Billy Goat Mode" just half...
Maybe somebody picked up the wrong sled, I'd be looking in the back to see if any other sleds in for repair are similar to yours. This could be one of those opportunity knocks type of situation. But i will also keep my eye out for ya.
I agree with snopro, I use Smiths and never have fog problems, unless i do something stupid and drop them in the snow or leave them upside down on the bars.
Go with the Ski-doo Tundra LT with the 600 ace engine. Light machine and there built to pack gear. Electric fan makes sure you don't overheat the engine. 4 stroke, so just an oil change at the end of the season, and runs on 87 octane gas. I used a renegade 600 ace last year for surveying...
Rode Kakwa today, probably the best snow I've ridden, ever. Its waist deep anywhere off the main trails. Settled a bit by wind in open areas. You need every inch of track and every extra RPM to get anywhere. Bring lots of fuel!!
Drove through pass a couple times over the holidays. Not as much snow as usual in powder king area. Close to 3 feet at parking lot for Bijoux, 4 trucks in parking lot yesterday. Nobody at Beaver Creek yesterday, pretty sure the trail up is not put in yet. Lots of windswept snow in powder king...