hi i have an 84 larson that i bought as a project with a mercruiser 3.0. the boat seems to run drive fine but the engine has a knocking noise under load. it seems to sound fine or at least alot better in neutral even when revved up. but when your in the water accelerating and cruising at mid to higher rpm it is load and does increase with rpm. the engine has all new main and rod bearings, also has new u joints and gimbal bearing. i have been told it may be piston slap. does anyone have any experience with this? i am about to pull the engine and tear it apart to see if i can see whats going on but would like hear from others first if you think i am on the right track. or if you have any other idea of what it may be.
