QuestionWhen was looking to buy this 1977 Arctic Cat Panther snowmobile the owner started the engine and it smoked really bad. He said that he put too much oil in the cylinders when he stored it for the summer. I figured I would just run it a while and the excess oil would work it's way out. I bought it and I have tried to run it several times over the last couple years and it still smokes very bad, spits oil out the exhaust on to the ground (sometimes ounces!), and quickly fouls the plugs. I have filled it with fresh 50:1 gas/oil mix. It probably has a total of 30 minutes of run time.
I am thinking that he filled the cylinders full of oil, the oil ran down into the crankcase, and when it runs the oil works its way back out. If I keep cleaning the plugs and running the engine until they foul will it eventually clear out? Is there a crankcase drain that might speed up the process? Is there any other source of oil that could cause this problem?
Answer
Hello Dan,
There are a number of things that could be causing this problem. I think by now, any oil the guys has in there has probably diminished, but there could still be more. Here is what I recommend. Try using Champion Powersport plugs, the OEM plugs for your engine are NGK BR8ES. Arctic Cat recommends using only Fully Synthetic 2 Cycle oil at a ratio of 50:1. Using oil like Amsoil should help cut down on the fouling. What I think is a good possibility, is this. When a sled sets up for some time, the inlet needle inside of the carb tends to get gummed up, and stick. When this happens, it will cause the engine to flood, and you will see fuel oil mix coming out of the exhaust. Another thing to check, would be the carburetor air screw. There is a small screw on the side of it, that goes in at an angle, it is NOT the big screw that sticks straight out. Make sure that the air screw is not turned all the way in, and is at least one turn out. Also, try removing your plugs, and grounding them on the engine block. Crank the sled over, in the start position. There should be a distinct snapping sound, and bright blue sparks coming from the plugs. If there is a weak orange spark or yellow, you will need a new coil. Coils are available through www.mfgsupply.com or www.denniskirk.com . If there is still oil in there, all you can do, is ride it as wide open throttle as possible, until it clears up. There is no type of drain plug on the AC Spirit motors. Hope this helps you out. Let me know if I can answer any other questions at all. good luck with the Cat! --Arcticatman
