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Westerbeke 12.5K Problem-gctid403229

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    Westerbeke 12.5K Problem-gctid403229

    In trying to start my genny the other day I found that the Oil Pressure switch (#011552) described in the manual as "oil pressure switch - auxillary" was not working due to a broken connection. Upon ordering and installing the Westerbeke part and running the genny I am finding that once I release the 'pre-heat' switch the engine cuts out and will only run w/the pre-heat switch held in the on position. I have looked up possible problems( low oil, faulty oil pressure switch) and found that the oil level is full and I just replaced the switch. I am looking for some help from members that may have had a similar problem. Thanks in advance...Jim

    It is probably the switch.

    New parts are not always right. Unfortunately it is hard to tell for us laymen.

    The pre-heat starts a fuel lift pump, the glow plug and most important in your case, disables the oil pressure cut off.

    This last one tells us that it is 90% probable that the oil pressure cut off is still the issue.

    I have found with mine that I get an oil pressure reading when I have been cranking it for a while.

    If you do not you either don't have enough oil pressure or, that switch thinks that you don't.

    I learned all of this from the manual yesterday as I am having trouble getting mine fuel flowing in mine after a filter change.

    All well and good to know what the problem might be, but short of another part swap, I am not sure what you do next.

    There are some clever folks here, that will

    Good luck



      I had the same problem with my 12,5 Westerbeke a few years ago, and while all my notes for correcting this problem are on the boat 60 miles from here, I think the problem is that once you release the pre-heat switch you are not getting the necessary 12.5 volts to the fuel solenoid to make it work and thus make the engine continuously run. I think if you go to the Westerbeke site you will find this mater discussed under Technical Bulletin number ??? 39. Also do a search of this site as I know this same problem has been discussed before although I couldn't find it under any of my previous posts.

      Also, I know other members have had the same problem and will eventually chime in with a better description of the solution to your problem.

      If for some reason you don't get the necessary help, I will be on my boat late next week and will get back to you with more info.



        I think I was right and wrong. Right about the solution with the wrong number for the Technical bulletin. It is 175 and is accessible below:



          On the 12.5 there are three safety switches that will close the fuel shut off solenoid. What you are doing when hold the preheat switch is bypassing these safety shut down switches. These switches are wired in series and terminate in the connection box on the generator. Oil pressure and exhaust temp at the exhaust elbow and engine temperature are the three switches. A loose connection or bad safety switch will shut down the fuel solenoid. The lift pump on this engine is mechanical and if the engine runs with the preheat switch this is not your problem. The fuel solenoid is working as well because the engine runs with the preheat switch on. I would check the terminal strip in the metal box on the generator looking for a loose connection. You can check the rest of the switches by checking them for continuity, both temperature switches should have continuity cold, unfortunately the oil pressure switch requires oil pressure so this one can only be tested with engine running, you can do this by holding the fuel solenoid open by hand while the engine is running. Another way of testing each switch is by bridging each set of terminals on the switches until you find the failed switch. Hopefully one of these solves your problem. If none these do it you could have a loose wire at the switch in the pilot house.


            Thank U to everyone who responded. The problem was the fuel shutoff solenoid as described both SCARY and RRDARBY. Thanks again...Jim(AKA AnnaMorgan)