I HAVE A 2000 WELLCRFT MARTINIQUE.PORT MOTOR STARTED IDLING HIGH.MOTOR HAS 300HRS COULD IT BE THE TPS.ALSO TACH WAS WORKING THEN THE IDLE KI
AND THE IDLE KICKED UP AND TACH STOPPED WORKING
I can ony GUESS that you have Merc 5.7 TBI's. Yes? No? So, as a guess on the power, I'd check the IAC--idle air control valve on the back of the throttle body. Likely carbonized. Clean it or replace it..should be about a hundred bucks.