220 bayou will not start/run
 

I have a 1999 220 bayou that ran great when all the sudden I was riding it and it bogged down and quit. I have always done all the annual maintenance such as changing the oil, changing oil filter,lashing the valves, checking the time, and adjusting the clutch. I have checked the fuel, the ignition, the timing, the ignition switches, the spark plug, the spark pickup on the timing wheel, and some others and it still will not run. The electric start works and when I try and start it you can hear it firing and struggling but still will not make enough power to even run on its own please help me out.

Clean the carb out, remove float bowl and jets, blow them and the holes they came from out with compressed air. Check the choke is working properly. Do not alter mixture screws. If it doesn't run then, do a compression check, less than 90psi and, if the valves are set right, it is time to take the cylinder off for a check up.

I replaced the whole carburetor and still nothing, I did a compression test and it made 75 pounds but I just put a new set of rings in it prior to it breaking down and it ran great. My question is do you still think it's a compression issue because I tried to roll start it by pulling it behind another four wheeler and it made no difference

I changed the carburetor and it still did nothing. It's sparking so I checked the compression and it made 75 pounds which is strange because I put a new set of rings and gaskets on it about two months ago. I'm thinking I broke a ring or blew the head gasket. My question is what approach should I take for figuring out what it is?

There are only two possibilities, either the valves have closed up or there is something wrong in the engine's top end. Re-check valve clearances and, if they are OK, remove head and cylinder to find the fault.

How is the fuel quality? Mine behaved like that after it got some water in the gas from sitting for awhile.