I hear two different sounds, one when you start to turn the flywheel, and one at the end.
The first one MAY be rods or wrist pins, but is likely the connection between the crank and the driveshaft. To figure that out you would have to do what Buccaneer mentioned. Alternatively, remove the powerhead from the tower and retest OR have someone put a little back pressure on the rotating prop shaft while you do that test OR just wiggle the prop back and forth a little and see if you hear the same noise.
The second noise needs to be explored, I can’t determine what that is. Is it possible that the flywheel magnets are hitting the mag plate? Does that sound always occur in the same location of the flywheel rotation? Does it correspond to prop shaft position?
T
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