Hi Bob, the sea water pump, right? What is wrong with the old one? These are pretty sturdy units.impeller pump
Im told its an Oberdorfer but I found a Sherwood that looks exactly like mine on Ebay at much less money.......any thoughts?Is it a Johnson pump? If not, I would imagine it is an out sourced pump from a third party. Onan is not in the pump business.
Hi Terry..........yes its the sea water pump........i had a master craft mechanic on the boat for 5 hours trying to ascertain the problem..........Im not getting water out of the side of my boat and the generator shuts down before it overheats......the mechanic checked the thru hull and the hoses from the bottom of the boat up to the strainer and from the strainer to the pump and no water or suction is drawing into the pump..........he changed the gasket....no luck.....when he put in a brand new impeller and still no suction coming into the pump he told me it had to be the shaft not rotating and a seal must be broken in the back of the pump...........im not very savvy when it comes to these things so if you have any ideas for me I would really appreciate it as the pump is really expensive.....anything else you can think it might be Terry.........? thanks so muchHi Bob, the sea water pump, right? What is wrong with the old one? These are pretty sturdy units.
Im told its an Oberdorfer but I found a Sherwood that looks exactly like mine on Ebay at much less money.......any thoughts?
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Good suggestion, Les. Our pump cover gasket is pretty thin. Bob needs to make sure the mechanic removed the old gasket did not install another gasket over the old one.1) is the gasket the correct size, to thick no prime
Is this the one you found on e-bay? http://marineenginedirect.com/oberd...mqjMXTAuetKaswu6-oFnxCHTXnP928wwaAlksEALw_wcB It does list the model it applies to. Here is the one for an Oberdorfer: http://marineenginedirect.com/oberd...KmqjMXTAuetKaswu6-oFnxCHTXnP928wwaAlksEALw_wc Finally, here is the answer: http://www.pumpvendor.com/Sherwood_G905_G-905.html Of course, the best way is to take it off (or have it taken off) to verify before ordering, but I agree that it looks the same as what is in your photo. And, replacing the pump would appear to be the right thing to do.
BTW, I would get another impeller and gaskets if your decision is to buy that new-old stock. The impeller could be bad from sitting in that position a long time IMHO. Good luck!
Hi Terry...........thanks for your sage advice......we tested both scenerios you mentioned and neither seemed to be the problem.......we had water from the thru hull up into the sea strainer and then the problem starts as I cant feel any suction in the intake port on the water pump but the impeller is new and turns on the shaft........my genset has a heat exchanger......do you think that could be the problem if the heat exchanger is clogged with some kind of muck?......Im just trying to explore all possible avenues before spending the money on a new pump.........but I dont know what to do next.......thanks to all of the help I received here from you good people at least I know where to get the pump if that proves to be the problem.........thanks again to all for your help on this problem.Hi Bob, sheesh, at a loss here. The only two times the Onan shut itself down was when there was no coolant sea water being drawn in by the pump because:
1. Failed to place the sea water strainer cover on properly after cleaning the basket, so the unit sucked air past the seal preventing sea water from being drawn in by the pump, which caused it to shut down.
2. Sea water strainer sucked in a pile of marine gunk in a very dirty bay, clogged the strainer and caused the unit to shut itself down. During the trouble shooting process I did replace the badly worn original impeller. The unit has run normally ever since, and that was maybe 25 hours ago.
Beyond that not of much help here. Does the pump impeller drive shaft rotate when you turn the engine over? Be sure the sea water strainer cover is on and sealed tight. If so, you should be able to siphon in water to the pump. I'm not aware of a shaft seal that would prevent the pump impeller from drawing in sea water. These units are pretty simple in design. Perhaps a rebuild kit rather than a new unit? Just say'n.
If you can talk to Onan technical support, give them the symptoms and see what they say. Drill into possible scenarios with the support person before buying a new unit.