Advice needed on rusty fuel pump and seawater intake valve

[SteveB62]

Hello fellow Bavarians I need your advice/thoughts. I have a 2014 Bavaria 37 Cruiser which is experiencing some rust on the fuel pump bolts and I also have a "green" coloured seawater intake valve (see attached pictures). There have been some oxidisation issues on the starboard and stern engine mounts and the fuel pump itself which I cleaned up using a Dremel.
I recently had the boat out of the water and installed a new hull anode and sail drive anode, noting that the old anode was not worn at all. Perhaps the sail drive anode was not doing anything?
I am also concerned about the amount of rust on the rear (stern) of the sail drive, what are your thoughts on this? (see pictures) Should I just clean it up with the Dremel and monitor the situation?

[Yngmar]

Rear saildrive mount: That's minimal corrosion. Wire brush it off, apply rust converter and some paint. Absolutely uncritical.

Hose tail on engine seawater intake from saildrive: Not severe, can clean up and monitor or just replace the hosetail, they're cheap enough. Probably it seeped a bit, causing that.

Fuel pump: That's not nice. Looks like seawater got there. Need to be very careful with that and keep your engine clean, especially since on a hot engine corrosion is accelerated. Apart from the heat exchanger, engines are car parts, not boat parts and they cannot handle seawater exposure. I'd carefully clean up the corrosion, probably removing the fuel lines (which means bleeding air out later) and then applying rust converter and paint on the rusty bits.

I'd also be concerned about the clamping ring on the saildrive rusting. Those things are notorious for pooling any seawater spill in the rubber ring, which doesn't harm the rubber but the clamping ring that holds it corrodes. It'll need sorting or replacing when the time to change the diaphragm comes, but until then I'd clean up around it and treat it too.

[symphony2]

See my reply to your other question. The anode on the hull should show minimal depletion as it is not in a galvanic cell. The saildrive anode should show some signs of depletion, although this varies from location to location. Make sure there is good electrical contact through the mounting bolts and the face of the housing. Check for continuity. As already suggested the corrosion on the engine and drive bits inside the boat are result of damp salt water  - maybe a leak at some time in the past. The verdigris on the intake is quite normal and should clean off easily.

[SteveB62]

Thanks for the answers really appreciate the detailed response. I'm not sure how seawater has reached the fuel pump, perhaps evaporated seawater... I will clean these up with my Dremel and use rust converter plus paint.
I suspect the sail drive ring bolts are vibrating loose and nipped them up yesterday about a quarter turn on each one on the port side. There has been about 100ml of seawater in the engine bilge after a day sail with 1hr motoring. I clean this up after every sail so hopefully the problem is resolved for a period of time.

[symphony2]

You may want to check the outlet spigot of the exhaust muffler as this tends to corrode leaving pinholes that leak seawater when the engine is running. That ends up in the bilge under the engine.