Hi. So I have a 91 Phazer II and it runs well when cruising around at normal speeds. tonight when I was driving it, it was running fine(driving for about 15 minutes) and then I stop to wait for my brother and the it was idling really low like 1500rpm or less, so I adjusted the idle but that didn't see to help. Then the snowmobile started moving forward without me touching anything, and I put the brake on and that didn't stop it so I had to shut it off. So I drove it home and it was fine at high speeds and when I stopped again it did the same thing as a mentioned. I had the carbs cleaned last winter.

So what could be causing this problem?
any ideas would be greatly appreciated.

Thank you

i forget which but its either a lean or rich mix can cause your engine to idle high. inspect your intake boots for cracks and wear.

I think your problem is your primary clutch is sticking.
This is common
You will need to remove the primary clutch cover and clean the belt dust from the clutch especially the shaft
hose it down with like WD40 and clean the shaft up so that the clutch slides in and out nice
Thats why the sled moves fwd and is loading up the engine at idle
Not sure why but plugs go bad on Phazers alot (running on one cylinder)
But for sure the clutch needs cleaning