2006 Yamaha F150 making clacking/tapping noise when under a load

by Steve
(New Bern, NC)

Whenever I throttle up to get on plane, my F150 starts clacking and it continues to make this noise all the way up to full throttle. The motor does not make the noise in neutral at any rpm or in gear on the hose at any RPM. The noise accelerates with engine RPM. I can idle around in gear without noise until I push the throttle forward to plane. It does it, regardless of trim or Jack Plate position. The prop is in great shape as well. Every nut and bolt on the engine, jack plate and hyd steering has been checked.
The motor runs well, but seems to be struggling to get my bay boat on plane. Plugs have been changed, prop shaft lash has been checked. Water pump has been changed as well as the prop thrust washer. Fuel is assumed good, because the boat is used often and has been fueled with only non-ethanol fuel, with the proper additives used with every fill up. There is no water in the water separator filter and all the engine fuel filters are clean. I asked if it could be valves needing adjustment and the dealership mech was unsure.

Click here to post comments