yanmar 1gm10 - rebuild?

[Sniper]

Because of a chronic leak around the cooling pump, the front casing of my engine is badly corroded. Has anyone any experience of replacing this casing? Obviously the casing itself must be a yanmar part, but can bearings and seals be replaced with 'generic' (i.e. cheaper) components? I need to do this job as cheaply as possible since a new engine is out of the question.

Linked to this, is the pump a jabsco unit and can it be purchased more cheaply than from a yanmar agent? Alternatively, which components are likely to need replacing to stop the leakinging?

apologies for all the questions; all advice gratefully received.

 

[Talbot]

might be cheaper to try to pick up a second hand engine either for the parts or as a replacement

 

[paul_williams]

it has been my experiance that you can get any seal or bearing from a bearing supplier such as BSL, far cheaper than any so called origianal part.
you may also find that the one you buy from a supplier is a superior part, especially if you tell them what it is for, they will spec you a bearing and seal that is ideal for the situation.

 

[robbieg]

Theres a second hand 1gm for spares on ebay now if your looking for a second hand engine-nothing to do with me I just noticed the listing.

 

[ShipsWoofy]

Are you sure about a rebuild.

Depending how much corrosion you are talking about. I had the same fault which I have just added a repair guide.

I was able to use a brass headed wire brush to clean off all the engine corrosion and that on the pump. A quick spray with silver paint and it looks like new again.

I really would decide if replacement really is necessary before you go too mad.

 

[Rick]

I'd try cleaning it up first as Yanmar part unlikely to be cheap. As far as the pump goes, they usually only need a bearing, seals and new impeller, not wholesale replacement. On seals and bearings back to your question, Yanmar aren't I believe in the bearing / seal manufacturing game, so no advantage in going OEM parts there - a good bearing supplier should be able to get whatever you need. Have a look at the post further up that someone has done with photos on a 1GM rebuild.

 

[Topcat47]

Remember salt water corrosion on steel castings always looks worse than it is because Rust is so much less dense than the original metal. I'd strip the casting of it's oxide before shelling out for a replacement. Primed and re-painted it will probably last for years. They are designed for raw water coling, after all.

 

[Sniper]

Thanks to you all for your help. Dogwatch - your pictorial guide is very useful & I'll rebuild the pump first. As far as corrosion goes, I'm in the terminal stages with this casting. It has corroded to the extent that two of the threaded holes are half eaten away, as well as a significant portion of the mounting face on which the pump beds. I'm also on my second set of oil feed pipes!

 

[cindersailor]

I went through this problen when I rebuilt a 2nd hand 1GM. The alloy casting onto which the water pump mounts was badly corroded and one of the threaded holes for the pump was completely gone. My solution was to build up the area with epoxy putty (the sort you knead together to activate). If it is really bad you could consider incorporating aluminium mesh of the sort used for GRP car repairs (Halfords!). Once set this stuff is pretty tough and can be drilled and threaded. The pump only needs to be held in place and you do not need to tighten the bolts too much to get a good seal with a gasket. You will need to file the face where the water pump mounts to get a good mating surface with the pump. If you have not taken the casting off the engine you can avoid getting the filings into the engine by inserting a liberally greased rag into the hole which will collect the stuff. Hope this helps. The water pump location on these engines is one of their few failings. Unfortunately that boat has now moved on and I have an engine with considerably more failings (Petter Mini Twin), but at least the water pump is a sensible arrangement!