Raw water pump dynamic

[cyfarkas]

If the boat hasn't run for a while, I'm in the habit of a few short stabs on the starter with the STOP switch engaged. Actually learned that trick on Yanmar course years ago. The idea is to 'wet the engine in an oil bath before starting.

My question in in winter when the engine is winterized and thru hull SHUT tight. If I hit the starter and stop as above, will water move and dry the impeller. Will winterizing anti-freeze be all expelled overboard?

 

[Capt.Bill11]

I wouldn't think a few short stabs of the starter would build up any oil pressure.

 

[DavidM]

It won't matter. With the thru hull shut, you can't draw in any sea water and displace your antifreeze and if the antifreeze is pushed out, well so what- air won't freeze.

Antifreeze is a pretty good lubricant and any residual antifreeze on the impeller will keep it ok from being damaged for a few seconds of cranking.

David