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.

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.

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.

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.

One more thing you can do is with 3/4 tank of gas just put the line in a jar on the ground and put a pull on it. The line should then siphon gas naturally. Take a look at that stream. If it appears strong then back to square one. If not, then you could just replace the line with a splice as far back as it is easy to get too, just too see if you get a stronger stream when you do a pull on it. Who knows you might get lucky and cut out the bad section.

Could be a bad gas cap. Loosen or take off the gas cap and see if it runs and pumps gas.

Kohlar 5CKM21 genset not getting fuel | Good Sam Community

Gjac
Explorer III
Aug 29, 2018
rgatijnet1 wrote:
Glad you found the problem. Now in another 22 years, if it shows up again, you will know exactly what to fix. :B
Now that would be a high class problem to have at my age.
rgatijnet1
Explorer III
Aug 29, 2018
Glad you found the problem. Now in another 22 years, if it shows up again, you will know exactly what to fix. :B
John_Joey
Explorer
Aug 29, 2018
Glad you got it.
Gjac
Explorer III
Aug 29, 2018
I finally got a chance to drop the gas tank to check the generator fuel line. What I found was a very slight cracking at the end under the hose clamp that attached to the elbow going into the main tank. If I put my finger on one end of the hose and drew vacuum on the other the the hose held vacuum. So the fuel line itself was good after 22 years but was cracked under the hose clamp just enough to allow air to be sucked in. If I was away from home and could have gotten to the elbow connection without dropping the tank I would have just cut off 1/2 in of line and reattached like I did with the fuel pump side over the years and it would have fixed the problem. But the line being that old and about a foot short I replaced with a new line. Dropping the tank was not as bad as I thought it would be. Mike Brez on this forum let me borrow his motorcycle jack which made it easier. Now the only other problem is my remote switches don't work. I will start another thread for this issue. Thanks for all the replies.
77rollalong
Explorer
Jun 27, 2018
Some generators pull fuel from the same tank fitting as the truck, other have a separate fuel pickup about a 1/4 way up in the fuel tank, so you always have a 1/4 tank of fuel left after the gen stops if you have a single tank. The fuel pump should suck it up from the tank, if you can run it off a jerry can on the ground, since the main tank would be higher, you may have to drop the tank and check the pickup tube, and hoses from the top of the tank.
Gjac
Explorer III
Jun 27, 2018
I still haven’t fixed it. I ordered another fuel pump that Kohlar recomended but it still does not pump fuel. My next step will be to drop the tank to check the fuel line, but I wanted to go camping to use some fuel to make it lighter but have not had a chance yet. I just had the fuel pump changed last year and I believe the OEM pump had a new hose for the generator into the tank so I believe it has to be the hose from the top of the tank to the generator itself.
John_Joey
Explorer
Jun 26, 2018
So did you ever fix the issue? If yes, what was the problem?
Gjac
Explorer III
May 05, 2018
Brian in Michigan wrote:
Gjac wrote:
Brian in Michigan wrote:
Do you know what the pressure is on the output of the pump?
The pump is rated for 6-9 psi.

But is it putting out the 6-9psi? Have you put a gauge on it?
I don't have a fuel pressure gauge but it will pump a good stream from a can of gas.
BrianinMichigan
Explorer
May 04, 2018
Gjac wrote:
Brian in Michigan wrote:
Do you know what the pressure is on the output of the pump?
The pump is rated for 6-9 psi.

But is it putting out the 6-9psi? Have you put a gauge on it?
Gjac
Explorer III
May 04, 2018
Brian in Michigan wrote:
Do you know what the pressure is on the output of the pump?
The pump is rated for 6-9 psi.

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Kohlar 5CKM21 genset not getting fuel

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