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
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.