Stumbling & cutting out at W.O.T

[Worm Drowner]

Hello all,<br /><br />I recently purchased a 1999 9.9 4 stroke. When I open the throttle much past 3/4, the motor begins to stumble and even quits on occasion after running fine for around a minute, maybe 90 seconds. At times, it take a bit of cranking to get it restarted after it dies. If I run it below the speed where it dies and turn the ignition off, it restarts with no problems. The oil level is fine so I don't think it's cutting out from low oil pressure unless the pump is failing. <br /><br />I also noticed a bit of surging at low throttle while trolling. The surging doesn't affect the speed but I can hear the rpms vary up and down briefly.<br /><br />Any ideas would be greatly appreciated!<br /><br />Thanks.