Help with Rusting Power Trim Pump on 2003 90HP 2S

Hi..I have a 90TLRB 2 Stroke on a Whaler Montauk. Like the Yamaha 1988 70 it replaced, the power trim pump is rusting out. It has been gradually doing so since new. I see this happening on many Yamaha OBs kept in the water during the summer. There is also a bit of white powdering on the trim unit, though, not much. Is there any remedy for this? Is it a defect in the bonding system of an old motor design?

I replaced the zinc this year after thoroughly cleaning the motor bracket and bolts it attaches to. It will be difficult to determine if it's doing it's job and how much of it is waring away until winterizing in late October. The previous zinc (the second since new in 04) did not wear away as quickly as the original.

Any thoughts on understanding what's happening would be much appreciated...thanks...Jim.

[boats.net]

The trim motor housing is made of steel and will rust over time. Other than repainting it I don't know of any solutions.

[robert graham]

my 1999 Yamaha 90HP had some rust/corrosion on the tilt/trim components including the pump and motor. I used a wire brush and emory cloth to clean it real well, primed it and put some fresh paint on it and it's doing fine now. the whole trick is to get all of the corrosion off before priming and painting. now i spray down the tilt/trim mechanism with the Yamaha Protective Coating which leaves a heavy grease film on it and works great to keep the water off. then you can clean it and spray it down once or twice a year to keep it protected. I found a Rustoleum paint at Walmart in a Gunmetal Gray color that's almost a perfect match for the Yamaha motor paint. Good Luck!