[njrmahoney]

Trying to track down reason for overheat.
Right now, the raw water pump is sucking in about 1 Gal Per Min.
Does seem right? Do you think it should be more? I tested by placing intake hose in a 5 Gal Bucket marked with 1 Gal increments.

 

[deniseO30]

not enough. check impeller, heat exchanger (if it has one) strainer etc.

 

[njrmahoney]

OK, thanks, Thats a good place to start. I thought the flow rate seemed a little slow. Do you know what it should be sucking in? I have read 3-5 Gal per Min.

 

[engineer_sailor]

What are the circumstances around the overheating? Were you running at WOT for an extended period? Are you able to reach full RPM under load?

Would start by removing and inspecting the heat exchanger and zinc

Josh


Sent from my iPhone using Tapatalk

 

[njrmahoney]

First noticed after extended 3/4 throttle. then began to see it after around 15Min. at 1/3 throttle. I suspect the exchanger is gunked up.

 

[MarkSF]

I have the Universal 5424, with the Oberdorfer N202M16 raw water pump. I think the M18 has the same pump.

I recently measured the flow, and it was 2.2 gals/min at 1000 rpm, 3.3 gals/min at 1500. (That is engine rpm. Raw water pump goes at double the crank rpm). I measure the flow by timing how long it takes to reach the brim on my 2.5 gal bucket.

If you have the Sherwood pump, it should shift a bit more.

 

[njrmahoney]

Thank you , that is helpful.