I have a mercury 4hp 4 stroke kicker that started acting up on us last night. We had shot a fish and put the motor in neutral while we were playing the fish. For some reason the motor just cut off during the battle. My friend went back to crank it (which normally requires one pull when warm) and he pulled for like 10 minutes and it never fired. We tried everything. Choke on/off, no throttle, half throttle, full throttle, etc. Nothing. Picked up the motor and ran for a while on the big motor and it cranked first pull at the next spot. It ran until we shot the next fish and then it cut off again. Same thing. Wouldn't crank for crap and we had to move again. Next spot it only took one pull. It went on like this the whole night. We checked all that we could in the boat. The fuel bulb was primed and hard the whole time. Pulled the spark plug and it looked fine. Hooked it back up and laid it on the motor while we pulled and it sparked like crazy. Motor was still peeing when it would run. Manually pulled on the kill switch to make sure it was ok and it was. We are baffled on what has happened. Any ideas??