Mercury 9.9 Fourstroke ProKicker Chattering/Buzzing Noise

[Mikie Mikie]

I do have a 2006 Mercury 9.9 Fourstroke Prokicker BigFoot with power trim. It Has always ran perfect, Upon first under water impact bad chattering noise came from lower unit, insurance company replaced lower unit and gave me the old parts. Curious I took it apart, it had twisted the input shaft, and chipped pinion and forward gears it was otherwise un-harmed except for bent prop. Got Boat back on the water with new lower unit and new prop, hit a log and chattering noise came back, prop wasn't even bent but it was making a bad noise down there some where.To make a long story short I found the gears were clashing in the lower unit (I took it apart and fixed it myself because the dealer was none responsive). The strange thing about it was there were shims between the water pump and the main support bearing, the shims were not shimming anything where they had them, so I moved them to go under the support bearing which drew the drive gear (pinion gear) out of the forward/reverse gears so load is applied to the drive surface and away from the toe, and I checked the pattern with white grease. I have hit many under water obstructions since making this adjustment and the noise hase not returned. I informed Mercury of their error in manufacturing and they were not convinced, I let that dog lie. The only problem I have now is an annoying buzzing noise @ part to full throttle coming from up top around the linkage or something, can't really pin point it, tried wrapping choke rod with electric tape and stuff like that but something is still buzzing!