OCCASIONAL ENGINE RUNNING DURING OFF SEASON

I have a R31S with a Volvo D4-300. We use the boat mainly during the summer months accumulating about 75 hours of running time annually. However, during the off season we seldom use the boat and it often sits unused for months. The boat is kept in a cover slip in the Pacific Northwest where freezing issues are seldom an issue. The oil and filters are changed in the fall so it sits with fresh non-corrosive oil. I make a point every other week to run the engine for 5-10 minutes mainly to circulate the oil in order to keep the crank shaft bearings somewhat lubricated preventing a future excessive dry start from prolonged sitting. I know this does not have all the benefits of bringing the engine up to operating temperature but that is not my concern. Some say this occasional brief running to keep the bearings lubricated is a good practice and beneficial, some say it is irrelevant, others say the occasional starts are damaging and best to let it sit until needed. What do others recommend?

KBHARDER
STARBIRD R31S

I think what you doing is a little price to pay to keep your engine well kept.. No engine likes to sit without use, good practice to do what you're doing..

Why not use the boat? Take it out for an hour and run it up to temp. On a sunny day, the inside will be like a terrarium. In NC, we take the boat to a local restaurant with a dock and have lunch once a month.

In my humble opinion, what your doing is better than letting it sit for longer periods of time. As long as the engine can get warm enough to evaporate any moisture in/on it then I believe you gain nothing by running it longer.

fishheadbarandgrill said:

Why not use the boat? Take it out for an hour and run it up to temp. On a sunny day, the inside will be like a terrarium. In NC, we take the boat to a local restaurant with a dock and have lunch once a month.

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I agree, If you are going to start it anyway...why not? It might also reveal other things you might want to do before season.

I am basing my answer on experience with aircraft engines, but 5-10 minutes of running at low RPM is not enough time to get the oil hot enough to get rid of moisture. If I must run the boat at the dock, I put my RT31 engine in gear at 1100-1300 rpm for 30 minutes. In neutral, the Volvo computer limits you to 1500 rpm, but it takes forever with no load to get the engine warm.