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.

[Gjac]

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]

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]

Glad you got it.

[Gjac]

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]

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]

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]

So did you ever fix the issue? If yes, what was the problem?

[Gjac]

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]

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]

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.

[azrving]

What is the voltage at the generator fuel pump when it's trying to pump?

Are you trying to empty the fuel tank so you can drop it? If so use the in tank pump. You should or could have a schraeder type valve on the engine where you can remove the stem and cram a hose on the fitting. Then jump the fuel pump relay and pump into fuel jugs. You will be moving fuel and working with electrical stuff that can arc. Be careful. Dont work on stuff like this with it parked indoors if you can help it and park away from your building. Fires happen all the time from stuff like this and just wanted to mention it.

The are various electric fuel pumps for small engines generators etc, you need to have the correct one for your generator. Someone could put the wrong pump on it and then it gets replaced with another wrong part number. From there if all the lines are good there should be no reason for it to not pump. The slightest air leak on the suction side can mess these things up. A leak on the pressure side can burn you to the ground. Be sure everything is top notch. Protect any wires and fuel lines from abrasion. Use old tire tube, heater hose or whatever to protect things.

[BrianinMichigan]

Do you know what the pressure is on the output of the pump?

[Gjac]

wildmanbaker wrote:
I honestly do not know how the electronics on you generator work. If they feed to the pump is through a relay, the relay may be going bad, and after a while it does not stay locked in. Otherwise, it may be you will have to drop the tank enough to change the fuel line, as it may be closing during use.
Is your MH front end all good now?

Front end is all good, $5000 worth of repairs and parts. I cannot get a hose down fuel fill to siphon off gas(tank is full), I even tried a thin plastic line 1/8 in ID but could not snake it down far enough to reach gas. What would cause it to close? I was able to snake that thin plastic line inside the pickup line all the way to the 90 degree fitting on top of the tank thinking if the pickup line was had a hole in it, the plastic line inside it would by pass it. I am wondering if the replacement pump is just too weak to pull gas out of the tank.

[wildmanbaker]

I honestly do not know how the electronics on you generator work. If they feed to the pump is through a relay, the relay may be going bad, and after a while it does not stay locked in. Otherwise, it may be you will have to drop the tank enough to change the fuel line, as it may be closing during use.
Is your MH front end all good now?