Yanmar is a very common engine and parts are usually available any where you go.
You should probably change the impeller before you leave and also carry a spare.
More importantly would be to carry extra oil
, fan belts and some spare water hoses with appropriate sized hose clamps. You find these items are much more valuable and need than a raw water pump.
On the other hand if you haven't had a major service
on your engine, I would recomend you think about that.
Last year, our Yanmar 4JH3 reached its 1000 hour mark and among other factory recommendations, the Yanmar Service
Tech rebuilt the raw water pump and cleaned both the Heat Exchanger
and Oil Cooler, as required by factory recommendations.
I though most of this was probably overkill, but after seeing how difficult it was to get the raw water pump out, I was glad the tech did did the work instead of me.
Also both the heater exchanger and the oil cooler did have some gunk in them, even though the engine was only 5 years old and had 1000 hours.
I think NONAME gave some great advice... If you are traveling in US Waters, buy a Tow Card and if something fails have them tow you to a dock
or service yard where you can buy parts or hire someone to fix your problems.
We have been cruising for two years and have found carrying major components in most areas is not necessary and takes up a lot of room. Other cruisers we have know with major spare parts, like water pumps, injectors and starters either sold them or gave them away after a coupleof years.
The reason is smiple... you can have anything shipped to you in most areas.
Also we have found that most third world countries tend to be really resourceful and can rebuilt electric
motors and pumps quickly. Places like Central America
also have the ability to machine or fabricate just about anything you need or at least a temporary fix, until a part can be shipped.
OK and before I get flamed, yes, if I was going to someplace like the South Pacific
, where shipping takes 4-6 weeks I would carry a spare water pump and injectors, but probably not many other places in the world.