Perkins 4-108 Intermittent Raw Water Flow

[FamilyVan]

Originally Posted by Guy

You had a different problem. A Perkins has a gear driven pump.

I definitely have a 4.108 with a belt driven pump. 1989. I can take a pic, its only 10' away from me right now, but its dark down there, so I doubt you could see much even with flash.

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[model 10]

Originally Posted by FamilyVan

I definitely have a 4.108 with a belt driven pump. 1989. I can take a pic, its only 10' away from me right now, but its dark down there, so I doubt you could see much even with flash.

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Don't bother I believe you but WTF? Why sell an engine with a gear driven pump and a belt driven pump? What can you expect from a taxi cab engine.

[FamilyVan]

My water pump drives both cooling water and my seafreeze system. Idk. Its how I bought the boat.

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[FamilyVan]

And props to the taxicab with a 4.108, because I ran mine without cooling water for 200 miles and all I had to do was open up the engine room and slow down to 4 knots. Pretty good engine IMO.

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[APKetcher]

A little more info on the problem I encountered than I first offered. My engine, a Westerbeke 40-108 is in fact, the same engine that was produced and labeled a Perkins 108 was built in 1980. I encountered the same problem after sailing, no water flow through the raw water system when I first started the the engine. After several restarts I was able to achieve water flow through to the exhaust outlet. Many of these instances meant I had to stave off the Seatow or Tow Boat US vultures offers ,eager to throw me a line, as I usually sailed up to the point where I needed to drop sails and motor into a channel to my mooring. This generally occurred while I was dropping a hook to keep me out of the shallows while I resolved the problem.
The quick fix was to open the flow circuit of the raw water, I had already played the face plate, gasket size, impeller change, game to no avail. Once i had water flowing freely from the heat exchanger outlet I moved on to the wet exhaust inlet. I knew this had to work because I had tested and changed out the vacuum breaker. This would get me flow through the exhaust and get me on my way. But, until I flushed and wire brush cleaned, (Rodded), out the oil cooler and heat exchanger tubes, the problem re-occurred every time I needed the engine. I also found bits and pieces of impeller and a Wooddruff key the PO had let slip into the cooling circuit.
The impeller change as well as the wear on the Sherwood pump cover, which on a 108 is direct drive, no belts or pullys come into play,and gasket size can contribute to poor flow. But no flow is a problem that should be traced to its root cause or it will continue to bite you in the ass when you least need it.