I have a KW Stealth with a 1994 115hp yamaha 2 stroke. My problem is I can run about 2mi. at 4500rmp and the motor will start to buck and then shut down. I wait about 30 second pump the ball and she'll run about a 1mi. and do it again, the longer I wait to restart the motor the longer she'll run. I have connected a portable 6 gal. tank to motor and it runs with no problem. I have also checked the inboard gas tank vent and it is clear. Any suggestions out there?