Advice on corrosion on engine

[keirah]

Hi,

I'm looking at upsizing from a wayfarer to a small yacht. I have found a yacht that appears in reasonable condition for her age (11 years), but I am worried about part of the engine showing heavy signs of corrosion (picture attached). I believe the engine is a Yanmar 1GM10 (sea water cooled) and it's the area below/behind the alternator that concerns me.

Would anyone be kind enough to offer any advice about whether this is a serious problem and if the engine could be economically restored (professionally or otherwise) to a more acceptable condition?

Thanks in advance...

Keirah

 

[sailorman]

may be due to the anode plate leaking or when salt water has not been cleaned-off after an anode change.
the anode is situated below the alternator & generally easier to remove the alternator when changing the anode

 

[rob2]

I've never had an engine in such pristine condition as the one in your photo! Of course, you can get someone to clean off the corrosion and repaint the engine. After a few years it will corrode again, the salt laden atmospher with the engine's own heat accelerating the process will eventually break down any protection system. On the other hand surface corrosion will not stop the engine from being fully functional. The only real known corrosion problem with this engine is the oil pipe beneath it, which can rust through in time - some people replace it with a custom made rubber hose with crimped on ends to prevent recurrence.

Rob.

 

[TQA]

Hi Keirah

Compared to most marine diesels of that vintage that one is pristine.

Remove the alternator clean off loose rust use any rust killer then paint with primer and Yanmar topcoat.

If the rest of the boat looks like the engine sounds like a keeper to me.

BTW been on a prolonged boat hunt myself and have seen boats offered for sale where NO paint is left on the engine, just rust.

 

[sarabande]

that rust looks as if it has been there for some time, so may be a slow water leak. Salty water would have white crystals.


BTW, it might be worth checking the valves to the water pipes. On the right of the pic is a red handled valve which looks a bit like a domestic one - and if so , they do rust and break quite easily.


I used to own wayfarers too !

 

[Tranona]

That is very common on 1GMs and is usually, as sailorman says, because the gasket for the anode plate has not been replaced. Take the alternator off and you can get at the whole side of the engine. Clean and prime with Hammerite primer for cast iron and spray with (very expensive, but good) Yanmar paint. It is only cosmetic in that area. The bit to watch as already pointed out is the oil pipe underneath the engine where leaks from the water pump can cause severe corrosion. The aluminium front housing can also corrode from the same source, so keep an eye on the pump and hoses.

 

[charles_reed]

Amazingly "clean" engine. The rust is probably from a leaking pipe-connection or an ill-fitted anode cover-plate and purely cosmetic.

 

[keirah]

Thank you everyone for the informative replies. Not as bad as I thought then.