Hey everyone, I'm new to the site but have spent alot of time reading posts from others. Looks like their are many knowledgeable people here which is great. I'm currently searching for help with my sled which I suspect might have one foot in the grave. It'll start right up with new plugs (and choke) it won't idle and after a couple seconds will cease to accelerate and I can hold the throttle wide open with the engine "idling" only. Pulling the plugs reveals the left one dark and wet, (gooey tar) the right one just wet. I've cleaned the carb adjusted idle and air/fuel screws to no avail. I even took the middle idle screw right out with no change.(ie: it still only idled with throttle wide open) I observed some dark discharge from the bottom side of the exhaust manifold and saw some oily residue below the engine. (looks like it might be leaking around the head gasket area) but I know nothing about snowmobile engines. I haven't checked the compression yet but I suspect it's okay since it ran last year. I'm perplexed and very depressed since we just got a bunch of snow overnight and today......................I'll keep looking through posts to see if I can learn more.