Was riding along probably 35 in my ('04 660) Rhino yesterday and it popped once or twice and was Dead. Got home and checked. No metal or pieces on plug, but i dropped the plug pullig it out so I don't know if gap was closed some by me or the motor. I have spark, fuel, all intake and all exhaust valves move and don't have slop. I can cover exhaust and it has gets pressure although I'm not sure how much cranking pressure it had before. Previous owner bored and valve job one year ago and it was running great with no signs of problems.... Any ideas I Sue Would Appreciate Hearing Them. Thanks and Happy Holiday!!!