Gen-Set Cummins Onan 2014 CB31

[NEDBETTY]

When we start the Jenny it shuts off after a few min (2 to 3) and I will start it about three times and then it will run ok.
Had a #7 pop up and had the marine shop install a new Impeller even though spring one was installed (Do ea year) well that was not a fix then a new pressure switch and that was not it ( getting expensive) then the mechanic put a hose down sea water strainer and all of a sudden it was fine.
It started every time since (about 12 times) then its doing the premature shut down each of my first 2 to 3 try's then runs?

Funny think when it happened first time the diver to a look at thru hull and all looked ok so must have been in the hose?

Strainer had some grass but not much. Are these Generators just real sensitive to minimal blockage. I am not even sure that is it, as I said about the third try she runs great.

Thanks!

 

[Automaticman865]

read something about the raw water pressure switch. Could be that and/or also perhaps if you check the wiring to make sure the connection( wiring, pins, etc...) have proper conductivity. You might also be able to bypass the switch just to test also.

Stuart

 

[FWTMD]

Just responding to the logic of it, as you have laid it out.

Sounds like you have the trail of the issue, when a hose down the seawater line cured it for 12 successive runs. Then returned. Since it cured it for a bit, it sure sounds like its something in that run. On another forum, with a different problem, a guy finally discovered he had a rather large oyster growing in his seawater line that caused a blockage!

It doesn't make sense to me (I can't quite picture it, but then I can't see your boat and the run) but it almost sounds like there is a dip along the run of that line that fills with sediment. The hose blew it out, or at least enough out, but then in time it refilled with sediment. If that's the case, then its either really clean out the hose fully and cure the dip, or replace the hose and cure the dip.

The suggestion to check the electrical connections always make sense. One by one, remove, clean, and reconnect and snug down. This doesn't answer why a hose down the line cured it for a bit, but its a good idea to do anyway while working on the system. Then again, if your mechanic jostled the connections enough to get a brief good connection back, its entirely possible that's it and the hose down the line is a false trail.

 

[NEDBETTY]

Thank you!!

 

[Bobby P.]

Yes, the Onan Gensets are VERY sensitive.

I had a similar problem the other day. Sucked up a Jelly fish.

Bobby