Started to notice a gradual overheating taking place with my Universal M25. If I pushed the throttle to 2500rpm the temperature gauge would slowly rise. Tried new impeller(s) without success. So, it became an " only go to 2500 for short periods. The other day I had started the engine and furled in the Genoa and then dropped the main. Only had a short distance to motor. I religiously check temperature gauge. What the (#$*(@.. temp indicated was approaching 180. A look over the transom indicated no water from the exhaust. Made the mooring at about 190 degrees. The the trouble shooting began. A cacophony of issues.. First the pump and impeller had run dry for 10-15 minutes. After things cooled a bit, the impeller was swapped out for a new spare. NO JOY. Decided to check the flow in from the seacock. Closed it, removed the strainer and re-opened.. Just a trickle .. Hmmm. Removed the service plug.. Still a trickle.. Ramrodded a coat hanger down.. Got resistance.. Sawed it back and forth.. Finally got a decent flow. Tried the engine.. No flow.. Removed the raw water feed line. Blew into it.. Eeh, so-so. Tried to and finally sucked salt water.. Primed the pump and re-tried the engine .. Still no water. Got the Admiral to come down the next day. Had her engage the starter while I watched the impeller. Well, the new impeller stayed put while the center hub spun with the shaft....Seriously ? Dropped the exchanger end caps..Clear as a whistle.
....Another impeller is accessed. It spins as it is supposed to. Pump cover goes back on, engine is spun up..NO WATER... Uggh ! I've come to the conclusion that it's one of three possibilities. First, the hoses.. Replaced the intake and pump to exchanger. Both were heavily cracked. Could its be sucking air that is preventing the drafting of water? Engine start time...NO WATER.. But new hoses.. Down to my last 2 possibilities. The cam in the bottom of the pump and the pump itself. Found and ordered CAM. Started looking simultaneously for a new Oberdorfer N202M-15 5 bolt . None, nada, zero, zilch... Oberdorfer decided to move from NY to MI in March.. Because of COVID, production has been on hold. I tried every place thinkable from east coast to west coast, gulf to Canada... SCARCE AS HEN'S TEETH they are... None to be had. Thought I'd found one at a distributor in MA. It was marked up over 150% above the lowest price I found, but as it turned out... NO GOTS...
The CAM arrived last evening. Quick trip to the boat this morning. Swapped out the CAMs, lubed up the impeller, re-sealed the pump and fired the engine..... Wait, what's that sound... a gurgle ... and ... and...and WATER.... Yeah !!!
I have a standing order in place for a new pump. I believe my pump is OEM and after 34 yrs the tolerances have got to be thin. It is interesting to note that the impeller that failed apparently is not an isolated event. So. if you change out an impeller be forearmed that there no guarantees that it will function as needed. The process of spinning over the engine while watching the impeller was a suggestion from a marine service tech who has witnessed many impeller failures in recent years..
....Another impeller is accessed. It spins as it is supposed to. Pump cover goes back on, engine is spun up..NO WATER... Uggh ! I've come to the conclusion that it's one of three possibilities. First, the hoses.. Replaced the intake and pump to exchanger. Both were heavily cracked. Could its be sucking air that is preventing the drafting of water? Engine start time...NO WATER.. But new hoses.. Down to my last 2 possibilities. The cam in the bottom of the pump and the pump itself. Found and ordered CAM. Started looking simultaneously for a new Oberdorfer N202M-15 5 bolt . None, nada, zero, zilch... Oberdorfer decided to move from NY to MI in March.. Because of COVID, production has been on hold. I tried every place thinkable from east coast to west coast, gulf to Canada... SCARCE AS HEN'S TEETH they are... None to be had. Thought I'd found one at a distributor in MA. It was marked up over 150% above the lowest price I found, but as it turned out... NO GOTS...
The CAM arrived last evening. Quick trip to the boat this morning. Swapped out the CAMs, lubed up the impeller, re-sealed the pump and fired the engine..... Wait, what's that sound... a gurgle ... and ... and...and WATER.... Yeah !!!
I have a standing order in place for a new pump. I believe my pump is OEM and after 34 yrs the tolerances have got to be thin. It is interesting to note that the impeller that failed apparently is not an isolated event. So. if you change out an impeller be forearmed that there no guarantees that it will function as needed. The process of spinning over the engine while watching the impeller was a suggestion from a marine service tech who has witnessed many impeller failures in recent years..