If you are worried about the impeller deforming, then as long as the water is not frozen, just turn the motor a wee bit each time you visit the ship.
Not every one is into maintenence. On a long haul you have to be into it, or have someone along who is.
Changing the engine oil is a simple one, given a wee bit of tuition.....
Go to boat.
Warm the motor.
Stop motor.
Suck out the engine oil via the dipstick hole (rarely is there a usable drain plug).
Suck out the gearbox oil via the dipstick hole (ditto).
Take off engine oil filter using a wee chain wrench.
Put on new engine oil filter, hand tight.
Refill engine oil.
Refil gearbox oil.
Start motor.
Stop motor.
Make tea with milk.
Drink tea.
Wash cup.
Go home again.
If you are improvising a coolant supply with a hose when your boat is on the hard, make sure you don't turn the hose on until the motor is running and make sure you switch off the hose before you stop the motor. You must, or the motor just floods a few of the cylinders via their
exhaust valves to the brim with water.
If it happens, your first warning will the heart-stopper of seeing water dripping out of your air filters. Don't despair, but don't start the motor. Pull the injectors out (not the biggest of jobs) and suck the water out of all the cylinders, by mouth with a drinking straw if you must, or use a wee oil lift
pump, or something. I have had to do that for other reasons.... not the hose error.... but an error nearly as bad.
Now run you engine for a minute or two and check your oil colour. If it turns a horrible mustard-green, you've got water in the sump (past the rings), and you need to change the oil and filter. It will still be OK though, as long as the water is not left in there too long.
Sometimes a tired O-ring on your water
pump will squirt water into the motor at the water pump housing. The symptoms are similar.... mustard oil. It is easy to fix. I had that one too.
The motor is still running well, 11 years on.
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