Is the motor getting hot ? ---Is the alarm going off ?-----------Have you checked the telltale hose for blockage.--------And most folks leave the impeller in the motors for too many years.-----Should be replaced about every 5 years.
The first thing to do is check the telltale nozzle. These cowling nozzles do plug up, esp if the engine has been run in shallow waters much. If it's clear, then you've got a more serious problem. Follow racerone's suggestions.
