This tuner assembly came out of a 1985 15hp. Above is a photo of what happens. By my thumb is the grommet that is at the top of the water tube.
The water pump was burned up, rubber transfer to the stainless housing was 360 degrees and the blades were gone off the hub of the pump.
After failure the opening in the grommet was less than the cross section of a BB. You can clearly see that the grommet has been burned and melted.
There was no evidence of corrosion between the tuner housing and the grommet on this one although that happens frequently.
The head gasket blew which allowed salt water into the cylinders and out the exhaust which is the white junk you see at the top of the tuner.
The powerhead was complete junk by the time the customer decided to take it in and repair it.
All fasteners came out easily. Customer stated it was an occasional salt water engine.
Since the powerhead was one of the black powerheads it showed nothing color-wise that it had been overheated.
