Kohlar 5CKM21 genset not getting fuel

[Gjac]

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.

[TNGW1500SE]

I see by your profile it's a 1996. Pull the tank and replace the hose. I bet it's collapsed inside. It's time for a new hose anyway. Prepare to cuss a lot. It's not fun.

[Gjac]

wildmanbaker wrote:
This will not fix the problem, but it may help isolate the problem. If you have access to compressed air, take the gas cap off and try blowing into the fuel line to the generator with the air. There should be enough room to get up underneath and see the top of the tank to see if there is dust blowing from the line anywhere. It will also verify that the line is not collapsed or plugged. What John and Joey said applies.
Good luck.

I wish there was enough room to see. I tried with mirrors and a flashlight and even tried to put my cell phone up there to take a picture but both the front and back are blocked. But I like your idea though. I have blown into that line and can hear air bubbles. I had my fuel pump replaced last year while on a trip out west and had an intermittent problem ever since, then found my fuel pump positive wire only connected by one wire strand then it finally broke. That's when I ordered a replacement and thought this was going to be easy fix but was not.

[wildmanbaker]

This will not fix the problem, but it may help isolate the problem. If you have access to compressed air, take the gas cap off and try blowing into the fuel line to the generator with the air. There should be enough room to get up underneath and see the top of the tank to see if there is dust blowing from the line anywhere. It will also verify that the line is not collapsed or plugged. What John and Joey said applies.
Good luck.

[Gjac]

1995brave wrote:
Could be a bad gas cap. Loosen or take off the gas cap and see if it runs and pumps gas.

I was hoping that was the problem, but removing the gas cap makes no difference.

[1995brave]

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

[John_Joey]

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.

[Gjac]

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.

[John_Joey]

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]

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.