My 1999 Johnson 8hp starts fine, runs for 10 min at full throttle then dies. It will not restart for about 10 min. It has done this 4 times. The last time it began to die, I started pumping the gas line bulb. It still died but it wound down about 5 second longer before it completely died. I replaced the plugs and changed the gear oil after the first incident. I was thinking electrical problem until this bulb pumping seemed to have some limited effect. Thanks for any ideas on my problem.