Yanmar 1978 SB12 Winterizing

[Inamist]

Hi All,

I am a new boat owner, and just bought a Bristol with an old Yanmar in it this spring. Its a single cylinder diesel, and I just hauled the boat and am getting set to winterize the engine.

I have been reading that one of the most important things is to change the oil and oil filter before the winter. The old SB12, oddly enough, does not have an oil filter. Instead, it has a 'Lub Oil Strainer' according to the manual.

Before I realized this I searched everywhere looking for the oil filter part number. No wonder I couldn't find it.

Does anyone have any experiance with this sort of system? Whats the best way to maintain it, and be sure my oil is clean?

thanks!

[Ziggy]

If the engine made through 32 years without an oil filter, it's a good bet it's pretty tolerant of oil contamination. But I believe it's possible to retrofit an off-board oil filter if you want to be extra nice to your engine.

[Inamist]

That's a really good point. I guess I'll just change out the oil, drain the raw water coolant, and perhaps replace the zinc and fuel filter.

Any other tips for an old engine to make it through a cold winter happy?

[KillerBoo]

1) Drain the raw water side of your cooling system, attach hose to the impeller inlet
and stick it in a bucket or similar filled w fresh water and a run the engine for a few minutes. Keep a hose with running water from a tap in the bucket/barrel to prevent it from draining and damaging the impeller. This is to flush out any salt water that will otherwise have a baaaaad impact on your engines´ raw water system

2) Pour antifreeze (preferrably the kind with anti rust capabilities) and mix w water to obtain a protective temp point a bit below the lowest expected temp in your area. About 10 litres would do it. Start the engine again and let the antifreeze flush through the system. STOP THE ENGINE just before the water is all sucked up!!
IF USING a toxic antifreeze, be sure to collect it as it flushes out with the exhausts. In my part of the world we use 50/50 solution that protects from freezing even when the mercury falls below the -35 C mark.
Don´t forget to check the fresh water side of the system, so it too has a anti freeze protection.

3) Change the oil while the engine is still warm. That way you wont have to go over the same procedure again. (But you don´t HAVE to change the oil before the winter, it can be done in the springtime as well, with no problems attached.

4) Remove the impeller, perhaps smear it a bit with vaseline or similar to keep it ok for next year (unless you´re changing it anyway as most ppl do here)

5) I´d change the diesel filter too if I were you.
And if the diesel sold in US -like it is here- has the equiv of the RME-additive (swedish word for a mix of canola oil, methanol and calcium chloride to get what they like to call environmentally friendly bio-diesel) in it, then you should pour some anti bacteria stuff into the tank as well. In Sweden we have a brand called Grotamar, but not sure what your equiv would be. Otherwise, if you happen to have some water in your fuel tank, you might get a nasty jelly type of blobs messing with your fuel system next year.. NOT fun when you have to rely on the engine for whatever reason.

Other than that, give her a kiss every now and then..