97 Polaris Storm running on 2 cylinders

I have been out of snowmobiling for about 15 years now, and purchased this sled as a fixer upper. The center cylinder is not firing, but the kicker of it is, sometimes it fires up and runs backwards, when it does this it runs on all 3 cylinders!!!

I have done a compression check it has 125 psi across the board
I have cleaned the tank and carbs, the cylinder is getting fuel
I have checked the pulse lines and the Fuel pumps, they are both good
I have checked the ignition timing, its right on the factory lines
Ignition system is all good, firing all 3 plugs, I also swapped coils on the cylinders to check for a dead coil.

I pulled the center cylinder apart to check for base gasket leaks, and all is good. Carb flanges are good, as well as the reed valves...

I'm at a complete loss now, I have tried everything I can think of, I hope someone here can shed some light on this for me.

Thanks in advance for the help!
Nick

97 Polaris Storm running on 2 cylinders