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Kubota Stamford Genset

Discussion in 'Generators' started by Marblehead01945, Sep 15, 2021.

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  1. Marblehead01945

    Marblehead01945 Member

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    All,
    I have a head scratcher with our generator. It will run for an hour or so and the cut out. Wait a bit, start it up again and it will run for 20-30 minutes. All gauges (oil pressure, temp and voltages normal). Water pumping out fine. No oil in the exhaust water. No coolant issues that I can tell. Recently I noticed a teaspoon or so of oil leaking after use from a place I can't get to around the middle of it underneath. Its a little Kubota engine 14KW V1505 with a Stamford hooked to it. Any thoughts of things to try and troubleshoot this? Anyone know of any services places in the Northeast US?
  2. Capt Ralph

    Capt Ralph Senior Member

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    Shut down switches and gauge senders are different devices.
    You have a safety switch messing up on you. Disconnect them one at a time and let run till issue solidly goes away.
    Start with the oil pressure shut sown switch first, probably where the oil leak is coming from.
  3. Slimshady

    Slimshady Senior Member

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    Ralph is spot on.
  4. Marblehead01945

    Marblehead01945 Member

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    thank you. I will check that out and report back on my findings.
  5. Pascal

    Pascal Senior Member

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    Doesn’t it shutdown clean and quickly or does it stumble and loose power before shutting down?

    if quick, then indeed it s a safety switch. I always carry spare switches.

    Double check the temperature with an ir Gun on the Tstat to be sure it’s not running hot and double check the gauge

    If it stumbles around before stopping it s likely to be a fuel supply problem.
  6. Marblehead01945

    Marblehead01945 Member

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    It shuts down clean and quickly. No stumbling. I just need to find where those switches are located. Probably inside where the gauges and start up toggles are located I bet. Good idea to carry spares. First time since new in 2007.
  7. Capt Ralph

    Capt Ralph Senior Member

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    The safety switches are on the engine. Usally but not always near the gauge senders. Maybe one on the exhaust riser.
    I'm not referencing any control box switches or relays,, yet.
  8. Pascal

    Pascal Senior Member

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    If you could find a wiring diagram it would help. There should be at least an oil pressure switch on the block and a coolant temp switch near the Tstat.

    some switches are designed to open when tripped (cutting the ground) other are designed to close, grounding the circuit. So in some cases to temporarily bypass for troubleshooting you can disconnect the switch but may need to ground the wire


    Some gens also have a switch in the raw water flow and in the exhaust manifold
  9. Marblehead01945

    Marblehead01945 Member

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    I did some troubleshooting over the weekend and it sure points to the Oil Pressure switch. I unplugged the multiconnector that has that on it and ran it for a couple hours and everything ran perfectly. I think I'll probably start by replacing that and see where we're at. Of course it has to be on the hard to get at side so I'll need to slide the unit out to get to the back side after I actually find the part.
  10. Capt Ralph

    Capt Ralph Senior Member

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    The sender is usually factory.
    On the valve cover should be the whole model number and serial number.
    Take this to any Kubota dealer and order the sender.
    With the part in hand, size the correct socket to it and ad some sealer to the threads (if not already prepped).
    You may be able to replace it half (or more) blind.
  11. bobhorn

    bobhorn Member

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    I always thought it was wrong to apply thread sealant to an oil pressure switch. It needs to be grounded to the block.
  12. Capt Ralph

    Capt Ralph Senior Member

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    Gang wars have started on less of different thoughts than this.

    I did think that same way. Even scared to use anything on engine zink threads.
    To avoid over tightening or damaging on some items just to stop a leak, I would try to seal just the last threads to screw in.
    Still a PIA.
    Then I noticed bare metal on the threads when taking things apart? There is metal to metal contact that cuts thru the thread sealant.
    It's not a pound of teflon tape, just a couple of wraps, thin line of 515 or RTV.
    Just snug it in and it works. No over tightening and still no leaks.

    Never had a problem.
    Give it a try, some sealant, screw it in and out. You will see the threads cutting thru the sealant.

    I have never Ohm'd it out but believe it would test fine also.

    Using isolated or two wire senders with lots of dope would zero this issue also. No need to make contact to the case at all but may cost more.
    Last edited: Sep 20, 2021
  13. bobhorn

    bobhorn Member

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    Thanks, that's basically what I do, even though I've been told it's wrong. But now that I know Capt Ralph agrees I feel much better.
  14. Capt Ralph

    Capt Ralph Senior Member

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    Oh, I'm glad we agree.
    Was cringing there for a few.

    Just remember, it is swamp mechanics. But nothing has ever come back to haunt me.
  15. Marblehead01945

    Marblehead01945 Member

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    Just to put closure to this- Got the Oil Pressure switch from Phasor> Southeast Power and rolled out the generator to get behind it. It turns out the little angle adaptor that the the oil pressure switch is connected to was loose hense the leaking oil. Replaced the switch and while I was at it and behind there replaced the sender because the oil pressure gauge was acting sporadically. This fixed the shutting down part but the gauge was still being wonky. That turned out to be a loose wire on the back of the gauge which I tightened up. Thank you all for saving me hours of time and probably money. Good one....
    Capt Ralph and chesapeake46 like this.
  16. Marblehead01945

    Marblehead01945 Member

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    Post information> The generator worked all the way down the coast (NH to Jacksonville) 5 days. The last day it wouldn't start at all and shut off after releasing the start toggle. Strange.... definitely different symptom than when it ran for an hour and then shutoff. Replaced the solenoid. That fixed it. Runs like a champ now.
  17. Capt Ralph

    Capt Ralph Senior Member

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    You still in Jax?
    I came up this morning.
  18. Marblehead01945

    Marblehead01945 Member

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    Sorry we missed you. The last leg was to Palm Beach. The boat is at the Ft Lauderdale Boat Show this week at the HMY booth. Check it out if you are there. Its a 2007 Rybovich 54.

    Attached Files:

    chesapeake46 likes this.