2005 HPDI

[tully]

I RECENTLY HAD A NEW POWER HEAD INSTALLED AND THE COMPUTER READ OUTS WERE SENT TO YAMAHA AFTER BEING RUN FOR TWO HOURS BY THE DEALER THEY SAID THE THROTTLE POSITION SENSOR WAS SET WRONG LIKE6.4 DOWN TO 6.3 WOULD THIS MAKE THE ENGINE HAVE A BOGGING SOUND WHEN IDLING AND ABOUT 3000 RPMS OR COULD IT BE A PLUG HAS FOULED BECAUSE THE COMPUTER BREAK IN ALSO THE WAS RUNNING GOOD TILL THE THROTTLE SENSOR WAS CHANGED

[boats.net]

You need to take it back to the dealer so they can recheck it. The dealer will want to see the spark plugs to help them diagnose engine.