Lucky you checked your plug or lucky that fan was continously running, my bro-in-law just fried his 400ex due to lean running. He also had installed a K&N filter.However the plug upon inspection was a light tan -go figure- the dealership said we are looking at $800 just for labor.

 

I'm not convinced that the jet needle Bombardier uses in the stock carb is rich enough for running a highflow K&N filter. I think I'll remove it to be safe.