I have vibration that chimes in just over idle. The vibration is only present when the steering nozzle is straight. If I turn the steering wheel a few degrees in either ditection, the vibrstion goes away. Switching from forward to reverse also seems to change is presence.
This is a new motor (BBC) for this boat with a 3 point mount. Previous motor was a 460 Ford with 4 point. I also rebuilt the pump with new shaft, bearing, bowl bushings, and wear ring. Also replaced seals and packing. The pump spun freely after rebuild and did not drag.
When I set the motor in I placed an angle gauge ontop of the pump just behind the bearing where the serial number is stamped, 8*. Angle gauge on the harmonic balancer reads 7* with the engine in place. Left to right, the engine is off center 1/8".