I acquired a nice little Arctic cat 90. It was given to me in non running condition. It was low on compression so I put a Polaris cylinder, piston and head on it. Now has great compression of 130 psi. Got it all together and it wouldn't fire. Checked the spark and it seemed a bit weak so I went to testing the stator. It was out of spec so I replaced it with a new OEM. Has great spark and still won't fire. Won't even pop on starting fluid. Can't figure out what I'm missing. Haven't checked the reeds but I would think it would fire, even if they were bad.

 

So I replaced the coil and now have great spark. Machine will run on ether for a minute then dies. Now assuming fueling problem. Carb is clean but I'm not familiar with the electric choke and wondering if that could be part of the problem. What controls it? I took the choke mechanism off the carb and noticed the needle doesn't move when it cycle the key. Any insight on this?

 

The choke is on all the time unless the engine is running, then AC direct from the stator goes to it, which heats up a coil of wire. A wax thermostat, next to this coil, gets hot and closes the excess fuel passage. Once the engine stops the coil and thermostat slowly cool, opening the passage so excess fuel can be fed to engine next time it starts up. Some are a little more complex, but that is the basic idea.