Does anyone know the spec water flow rate for the sea water (raw water) system of the Yanmar 2GM20F (2 cylinder, 16hp @ 3400rpm) model engine?
Yanmar Cooling Water Flow Rate
- Thread starter Roger Wood
- Start date
As long as the seawater pump is the original factory installed, according to your service manual on page 7-8, 700l/hr @ 2720 RPM.
Yanmar 2GM20F Service Manual
Len P, thanks for info, this helps. Not doing much sailing lately, most working on diesel engine.
To complicate matters, Yanmar used two different manufacturers for their raw water pumps. They will either be Johnson or Oberdofer. The engines that came directly from Japan had one and the engines finished in Europe had the other. I believe that most of the American purchased engines came via Europe.
More than likely there is a decent amount of headroom (what the pump puts out vs. minimum needed to keep engine from overheating.) Example from my experience with a Uni M12 - When I had reduced water pump flow thanks to some broken pump impeller vanes I actually heard a throatier sound out the exhaust pipe which tipped me off to have a look at the temperature gauge. It was showing 195 instead of the normal 165. Did not overheat but I got that impeller out of there pronto and pulled the hose off the pump end and also the heat exchanger end where I found a couple of impeller pieces.
