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Gjac's avatar
Gjac
Explorer III
Apr 27, 2018

Kohlar 5CKM21 genset not getting fuel

Genset runs fine when I draw from a gal can of gas but will not run when hooked up to the main tank. I thought the main hose might have a pin hole in it but when I use a hand pump on the line it will fill my clear plastic filter and not leak back into the tank. Bought a new pump 5 to 9 psi, thinking the old pump was weak, but still will not pump fuel to carb. Thinking maybe the fuel pump had the right psi but not the proper flow rate I took a clear plastic tube and put it into a container of gas to try to simulate the position of the main tank and the length of the hose to the height of the carburetor, and both the old pump and new pump pumped a good amount of gas. I am at a loss as to why I am not getting enough gas to keep the genset running. Any help would be appreciated.
  • Gjac's avatar
    Gjac
    Explorer III
    azrving wrote:
    Is there really enough fuel in the tank? Try it with a new fuel line back to the tank. If I understand you, you haven't actually replaced the line from the pump to the tank?
    The hand pump may be able to overcome a leak in the line.
    I have 3/4 of a tank of gas that is why I can get fuel up to the filter by sucking on the fuel line. A new fuel line would require the tank to be dropped and I wanted to make sure it was the line before I go through that effort. The hand pump could be stronger that the electric pump but I would think once you stop the pumping you would see the fuel drain back into the tank if there was a leak, but the fuel did not drain back.
  • With everything you said, IMO the only thing it can be is the OEM fuel line. Can't tell you what is going on either, just that ethanol gas seems to eat up older fuel lines and if you got gas in the tank and a pump willing to pump it, then it has to be in the delivery system.

    I know you had your rig for a long time and know this, but just to make sure. You need over a 1/4 tank of fuel for the genset to function, otherwise the gas tank outlet is not in the fuel zone but sucking air.
  • Is there really enough fuel in the tank? Try it with a new fuel line back to the tank. If I understand you, you haven't actually replaced the line from the pump to the tank?
    The hand pump may be able to overcome a leak in the line.