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Gjac's avatar
Gjac
Explorer III
Apr 05, 2017

Kohlar genset no fuel to carb

I de winterized my MH 2 days ago, the genset started after three tries which is normal for it. I ran it for an hr under load and then changed the oil, filter and spark plugs. After change it started right up but I noticed some foam in the oil after shut down so I thought I would start it up again and do another oil change to remove the white foam. To day I added some Seafoam to the crank case to thin out oil to remove foam, went to start it and it tried to start then nothing after multiple tries. Checked spark which was good but plug was dry. Removed inlet line from fuel pump and installed a clear plastic line and inserted it into a gas can, would not pump gas more than 3/4 up the clear tube. So I thought the fuel pump was bad. Removed fuel pump hit start and gas squirted out as it should. Tried this several times with the same results. I remove the pump again and used a bottle with a tapered end like a catsup bottle thinking I could force gas into the bowl, fill the bowl until float would stop the gas from going into the bowl and if it started then I would know it was the fuel pump. Cranked it but still no start. Plug was still dry so no gas got through. I am at the end of my abilities to solve this. Does any one know what would cause this? My Kohlar is a 5ckm21.

9 Replies

  • Gjac's avatar
    Gjac
    Explorer III
    Apr 08, 2017
    Thanks John, I finally got it running and drained and refilled. I think the problem was a stuck lever on the side of the carb that is controled by the electronic governed board. I now remember 2 years ago when the board went out I could move that lever up and down to control the rpm. I sprayed some lubricant on it and got it started. I'm not sure if it is tied into the choke or not but when I tried to start it this morning all it would do was crank until I lifted that lever then it started and ran fine. So there is still something not right but at least I now how to start it.
  • John_Joey's avatar
    John_Joey
    Explorer
    Apr 07, 2017
    I would change the oil (straight 30w Dino not syn) one more time but don't thin it out like you did. That Kohlar as a kill switch for low oil pressure. Been awhile since I knew this stuff so don't quote me, but I think if you disconnect that oil switch and it starts you'll have found your problem.

    That switch should be right in front of you with a single wire running to it. As I remember low pressure and it goes to ground. Also pretty sure it needs straight 30w but look it up to make sure.
  • Gjac's avatar
    Gjac
    Explorer III
    Apr 07, 2017
    j-d wrote:
    So this is a two-cylinder engine. Does the ignition use a Distributor, One or Two Coils, or one coil with two spark-plug terminals? ONAN uses that two-terminal coil. They ain't cheap but one can seem good and be bad.

    I also wonder if somehow the ignition is out of timing. What controls timing on this engine? I find it hard to believe it backfired and sheared the flywheel key, but something like that is still remotely possible.
    I thought the thing was out of timing also but when I read the service manual I learned there is no timing adjustment, I guess because there is no distributor. It has one coil with two spark-plug terminals which I replaced 3 years ago. I guess the timing is set by the magneto and it is all electronic with an electronic governor.
  • j-d's avatar
    j-d
    Explorer II
    Apr 07, 2017
    So this is a two-cylinder engine. Does the ignition use a Distributor, One or Two Coils, or one coil with two spark-plug terminals? ONAN uses that two-terminal coil. They ain't cheap but one can seem good and be bad.

    I also wonder if somehow the ignition is out of timing. What controls timing on this engine? I find it hard to believe it backfired and sheared the flywheel key, but something like that is still remotely possible.
  • Gjac's avatar
    Gjac
    Explorer III
    Apr 07, 2017
    Update I now have fuel to plugs, spark, checked compression 75 psi in each cylinder but still will not even try to start or even back fire. Sprayed starter fluid directly into intake and also each cylinder still nothing. Anyone have any ideas?
  • Gjac's avatar
    Gjac
    Explorer III
    Apr 07, 2017
    DrewE wrote:
    I'm not really a carburetor expert, but I can't imagine that being a good idea. The fuel pump is almost certainly a low-pressure pump, and the carburetor a precision device designed to operate at low pressures. Applying high pressure air to it would seem to me to be more likely to cause damage than resolve issues.

    I think some carburetors have a filter or screen on the input port that can be cleaned fairly readily without disassembling the whole thing. If it were mine, though, I would at least see about removing and cleaning the bowl part, if not rebuilding the whole carb. Sometimes the bowl can be removed without taking the carb off the engine. Sometimes it cannot.

    (I assume you've verified that the choke is working properly.)
    Yes choke is working, get spark, fuel pump is pumping fuel put plugs are dry after multiple cranks. I would think they should be wet with gas.
  • DrewE's avatar
    DrewE
    Explorer II
    Apr 06, 2017
    I'm not really a carburetor expert, but I can't imagine that being a good idea. The fuel pump is almost certainly a low-pressure pump, and the carburetor a precision device designed to operate at low pressures. Applying high pressure air to it would seem to me to be more likely to cause damage than resolve issues.

    I think some carburetors have a filter or screen on the input port that can be cleaned fairly readily without disassembling the whole thing. If it were mine, though, I would at least see about removing and cleaning the bowl part, if not rebuilding the whole carb. Sometimes the bowl can be removed without taking the carb off the engine. Sometimes it cannot.

    (I assume you've verified that the choke is working properly.)
  • Gjac's avatar
    Gjac
    Explorer III
    Apr 06, 2017
    DrewE wrote:
    Maybe a clogged or sticking needle valve or float assembly in the carb?
    Short of removing carb and rebuilding it do you think compressed air into the fuel line will help?
  • DrewE's avatar
    DrewE
    Explorer II
    Apr 05, 2017
    Maybe a clogged or sticking needle valve or float assembly in the carb?

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