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Vibrant93's avatar
Vibrant93
Explorer
Apr 24, 2016

Generator has spark, then it's gone....?

Hey guys. I've had a no start situation on my Onan emerald 5000 and think I've now finally narrowed it down as to why. After chasing down a dead fuel pump and tearing down the "throw away" carb I've gotten to the point where it'll fire but then immediately die. I put a trouble light on the spark plug boot and when I crank the generator over I'm seeing the spark plug fire 1-2 times and then that's it. No matter how long I crank the generator over there isn't spark after that 1st sequence. I see the spark plug wire runs to the back of the generator but I haven't had the time to dig into where it goes. Has anyone ever ran into a situation like this? I feel as though once I can get the spark to fire as it should, this thing will finally run!

Thanks for the help.
Class A

8 Replies

  • tropical36's avatar
    tropical36
    Explorer
    Jul 27, 2016
    Vibrant93 wrote:
    tropical36 wrote:
    Vibrant93 wrote:
    Just wanted to update this. I finally was at the point where I thought the genset needed to come out of the coach to be fixed. I was running out of time and didn't have the space to work on it so I took it into the shop. They did have to pull it and separate the gen from the engine to fix a broken rotor assy. I wasn't excited about the bill and wish I would have had more time to do it myself but all in all I'm happy that it runs good now. We just bought the coach back in March and had no idea how many hours were on it. My wife and I had a little bet about what it would have and she won. I guessed 550 and she went 290. It's got 320.

    What was the bill, if you don't mind, my asking, as I am always paranoid when hiring things out.
    I repaired my Generac, not so long ago after diagnosing a blown stator winding. Didn't even like the retail price of the stator, let alone hiring it out. Anyway, I finally got an acceptable price on the part and once I installed it, got it all back together and working well, I was more than happy with it. Glad for now, that I didn't go the Chinese route for replacing it altogether, as well.
    With what you and others have said about problems with their ONAN's, just maybe a Generac isn't such a Generwreck, after all....lol


    Apologize for the delay in response! Summer is here and things have been busy. I paid 650.00 for the repair which included a new starter which I wasn't anticipating. I got the call saying the bendex (sp) broke off the starter while they were doing the repair and that it needed to be replaced. They had already done the repair and the genset worked so I wasn't too angry about the whole deal. I did however express my anger that they didn't call me before they put the new starter in assuming I'd just want it done.

    Not too bad and good to know, since I now have an ONAN CUMMINS myself in a 7.5 Diesel unit.
  • Vibrant93's avatar
    Vibrant93
    Explorer
    Jul 27, 2016
    tropical36 wrote:
    Vibrant93 wrote:
    Just wanted to update this. I finally was at the point where I thought the genset needed to come out of the coach to be fixed. I was running out of time and didn't have the space to work on it so I took it into the shop. They did have to pull it and separate the gen from the engine to fix a broken rotor assy. I wasn't excited about the bill and wish I would have had more time to do it myself but all in all I'm happy that it runs good now. We just bought the coach back in March and had no idea how many hours were on it. My wife and I had a little bet about what it would have and she won. I guessed 550 and she went 290. It's got 320.

    What was the bill, if you don't mind, my asking, as I am always paranoid when hiring things out.
    I repaired my Generac, not so long ago after diagnosing a blown stator winding. Didn't even like the retail price of the stator, let alone hiring it out. Anyway, I finally got an acceptable price on the part and once I installed it, got it all back together and working well, I was more than happy with it. Glad for now, that I didn't go the Chinese route for replacing it altogether, as well.
    With what you and others have said about problems with their ONAN's, just maybe a Generac isn't such a Generwreck, after all....lol


    Apologize for the delay in response! Summer is here and things have been busy. I paid 650.00 for the repair which included a new starter which I wasn't anticipating. I got the call saying the bendex (sp) broke off the starter while they were doing the repair and that it needed to be replaced. They had already done the repair and the genset worked so I wasn't too angry about the whole deal. I did however express my anger that they didn't call me before they put the new starter in assuming I'd just want it done.
  • tropical36's avatar
    tropical36
    Explorer
    May 15, 2016
    Vibrant93 wrote:
    Just wanted to update this. I finally was at the point where I thought the genset needed to come out of the coach to be fixed. I was running out of time and didn't have the space to work on it so I took it into the shop. They did have to pull it and separate the gen from the engine to fix a broken rotor assy. I wasn't excited about the bill and wish I would have had more time to do it myself but all in all I'm happy that it runs good now. We just bought the coach back in March and had no idea how many hours were on it. My wife and I had a little bet about what it would have and she won. I guessed 550 and she went 290. It's got 320.

    What was the bill, if you don't mind, my asking, as I am always paranoid when hiring things out.
    I repaired my Generac, not so long ago after diagnosing a blown stator winding. Didn't even like the retail price of the stator, let alone hiring it out. Anyway, I finally got an acceptable price on the part and once I installed it, got it all back together and working well, I was more than happy with it. Glad for now, that I didn't go the Chinese route for replacing it altogether, as well.
    With what you and others have said about problems with their ONAN's, just maybe a Generac isn't such a Generwreck, after all....lol
  • Vibrant93's avatar
    Vibrant93
    Explorer
    May 15, 2016
    Just wanted to update this. I finally was at the point where I thought the genset needed to come out of the coach to be fixed. I was running out of time and didn't have the space to work on it so I took it into the shop. They did have to pull it and separate the gen from the engine to fix a broken rotor assy. I wasn't excited about the bill and wish I would have had more time to do it myself but all in all I'm happy that it runs good now. We just bought the coach back in March and had no idea how many hours were on it. My wife and I had a little bet about what it would have and she won. I guessed 550 and she went 290. It's got 320.
  • tropical36's avatar
    tropical36
    Explorer
    Apr 24, 2016
    Toddupton wrote:
    Check the low oil sensor

    May have an oil over temp like a Generac, as well, so once the oil level has been checked, disconnect both and see if that might be the cause.
  • Jim's avatar
    Jim
    Explorer
    Apr 24, 2016
    Going by memory here but I think most of the Onan's have a shut down system that removes spark if certain things don't happen while it's cranking. You can find user's guides for them online.

    Also, these troubleshooting guides are very handy: Troubleshooting Onan Gensets

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