3020 gas fuel starvation -- still

[Bob in SD]

Hello,

Trying to figure out if I've got some vapor lock or an intermittent fuel pump issue. My new carb had a sticky float needle. I replaced that, and the seat. Meanwhile outside temps warmed up (a lot) and I swapped the manifold blocks the correct way. It will start and run OK for 20-30 minutes, then die just like the fuel was shut off. Carb bowl is empty. If I crack the fuel line (at the carb), very little fuel comes out when I crank it. I rigged a remote tank, (lawn mower tank with a 1/4 inch fuel line), very little fuel came out when I turned that on with the bowl plug removed. If I let it sit awhile, I can drive it back to the barn (on the remote tank). I'm not sure if it's taking that long for the 1/4 inch line to fill the bowl or if things are cooling off. I'd think he plug being out would alleviate any vapor lock at the carb (cool rubber 1/4 inch line). If the tank is over half full, fuel pours out of the carb end of the fuel line when the built in tank is turned on (w/out cranking the engine). If I crack the line prior to the fuel pump (downstream of the inline filter) gas runs out when the tap on on (and dribbles out when it's off). That fuel line does come up about 4 inches then back down to the fuel pump, but that's up in front of the radiator and doesn't seem too warm. Could that be a problem?

I'm ready to try a new fuel pump (I don't have gauges to check the output pressure on this one, but there are times when it seems to not be working right). Any other suggestions?

Of the fuel pumps sold on this site, is there any reason to not get the one that can be repaired (Part No: TP-RE42211B)? The one on mine now appears to be off of a diesel (it has the priming arm and looks like pictures of the diesel pump I find on the web and here (Part No: TP-RE42211)).

Thanks,

Bob

 

[Roger in Iowa]

Make sure the priming arm is pushed back (not pulled to activate) so the pump can function.

Still not clear when fuel is coming out of carb or just dribbles.

Fill the fuel tank. Do you have troubles then? Bad fuel pump does not cause problems until tank is about 1/4 full. (personal experience)

Have you drained the sump in the main fuel tank. There should be a shutoff and separate drain for the tank. Open the drain (gas down the arm unless you make a pipe drain device) to clean bottom of tank of water, etc.

 

[Mike M]

I'd try the new fuel transfer pump.The check valves inside of them get worn out. That's what I did when our gas 4020 started acting like that. It was about the only thing left that we had not replaced before and they are not too many $$

 

[Bob in SD]

[i:654c4848f0]
Make sure the priming arm is pushed back (not pulled to activate) so the pump can function.
[/i:654c4848f0]

Back towards the block? I just discovered the primer arm the other day, I think it was kind of in the middle.

[i:654c4848f0]
Still not clear when fuel is coming out of carb or just dribbles.

Fill the fuel tank. Do you have troubles then? Bad fuel pump does not cause problems until tank is about 1/4 full. (personal experience)
[/i:654c4848f0]

I bought the new fuel pump yesterday. I will probably get a chance to put it on today. The tank is now half full, and I'll fill it further.

[i:654c4848f0]
Have you drained the sump in the main fuel tank. There should be a shutoff and separate drain for the tank. Open the drain (gas down the arm unless you make a pipe drain device) to clean bottom of tank of water, etc. [/i:654c4848f0]


I did this last year (first I drained it through the regular outlet, then I discovered the drain--I've since gotten the correct manual). I did drain most of the old gas out when I first started having problems (through the regular outlet, when I put a hose on the drain it leaked around the outside anyway). Even the gas near the bottom looked good (didn't separate) and ran OK in other equipment.

All of my gas cans are full now, so I'll probably fill it up first and see how the new fuel pump works. I guess if it doesn't die I still won't know until I get way low on gas, but at least I'll be able to take the mower back off of the Ford and mow w/ this one for awhile.


Once I get this problem sorted out, could this priming arm also be used for winter starts? I assume using this shouldn't push fuel past the float valve on a functioning carb?

 

[Roger in Iowa]

The arm should be back toward thh block.

No the lever will not act as a primer for cold weather starts. Usually not a problem in the winter starting on mine with just use of the choke control.

 

[sfsouter]

I know this thread is very old, but I read it and it helped me so I'll post my reply for the benefit of others. My tractor was doing exactly what Bob in SD had mentioned. It would not start to have issues until fuel level dropped to about 1/4 tank, when gravity no longer provides enough fuel flow on its own. Once I replaced the fuel pump, my clear fuel filter filed right up where it was only showing about 1/4 full before. I have a happy tractor again with more to drink.

 

[miangus]

Which carb, I had the MS carb on my 4020 boil the fuel in the carb and as near as I can figure bend the float adjustment. I had the same symptoms you describe even after changing the fuel pump. Pulled the carb and discovered that the needle valve was barely opening. Set float to factory specification and it runs like a top.

 

[sfsouter]

Hi Miangus, my '72 late serial 3020 used the Zenith with the main jet adjustment on the back. I fully rebuilt it and removed the electric shutoff on the main jet during that process. This improved operation but was still not behaving as it should. I suspected a problem with the accelerator pump as I could not source one prior to the rebuild in time. In reality it just wasn't getting enough fuel.