My 1940’s Farmall Super A runs great until I engage the PTO drive. I only get 15 minutes of mowing until the tractor wants to stall out.

[TrapperRick]

I’ve had the tractor serviced, oil, filters, spark plugs replaced. I’ve flushed and replaced the radiator fluid with green 50/50. I’ve replaced the transmission fluid with 90w and drained the gas tank and put in 89 octane gas. The tractor can run great until I engage the wood’s belly mower, then I get about 15 minutes of mowing. I’ve had this tractor for over 20 years with no problems and I’m mowing 5” of grass.

 

[AlinMO]

Make sure has good gas flow at carburetor.
Could be coil or condenser. I have had both fail when running for awhile.

 

[DaveBN]

With a load on the engine, like a mower, your using more gas. I suspect you have a fuel restriction somewhere. Carefully, with non metal tools, look in the bottom of the gas tank for flakes of rust. Remove and clean the sediment bowl under the gas tank including the fine screen at the top, then reinstall the sediment bowl with a new gasket. For test you could remove the plug at the bottom of the carburetor, then turn on the gas and see if you have a constant flow for 2 minutes. There is a fine screen in the elbow where the gas line enters the carburetor so check that also. If that doesn't fix you problem then you need to remove and clean the carburetor. Could be coil or condenser as mentioned above.
Dave

 

[Duner Wi]

Battery or Magneto Ignition? Less guessing receives potentially better answers.

 

[Powered By IH]

I’ve had the tractor serviced, oil, filters, spark plugs replaced. I’ve flushed and replaced the radiator fluid with green 50/50. I’ve replaced the transmission fluid with 90w and drained the gas tank and put in 89 octane gas. The tractor can run great until I engage the wood’s belly mower, then I get about 15 minutes of mowing. I’ve had this tractor for over 20 years with no problems and I’m mowing 5” of grass.

Describe what happens when it dies. Does it just die, or lose power, sputter, and then die?

 

[TrapperRick]

With a load on the engine, like a mower, your using more gas. I suspect you have a fuel restriction somewhere. Carefully, with non metal tools, look in the bottom of the gas tank for flakes of rust. Remove and clean the sediment bowl under the gas tank including the fine screen at the top, then reinstall the sediment bowl with a new gasket. For test you could remove the plug at the bottom of the carburetor, then turn on the gas and see if you have a constant flow for 2 minutes. There is a fine screen in the elbow where the gas line enters the carburetor so check that also. If that doesn't fix you problem then you need to remove and clean the carburetor. Could be coil or condenser as mentioned above.
Dave

Hi Dave. Thanks for your feedback. Much appreciated.

 

[TrapperRick]

Describe what happens when it dies. Does it just die, or lose power, sputter, and then die?

The tractor will lose power, sputter and almost die. I will engage the clutch to keep the tractor running and dis engage the PTO. The tractor will continue to run without the PTO

 

[TrapperRick]

Battery or Magneto Ignition? Less guessing receives potentially better answers.

I converted the tractor to 12v system. Battery has been charged and the tractor starts running immediately.

 

[TrapperRick]

I converted the tractor to 12v system. Battery has been charged and the tractor starts running immediately.

I converted the tractor 12 years ago.

 

[Duner Wi]

When you first start tractor and it is running fine with good power pull any spark plug wire and observe the spark. Now go use tractor till problem occurs. Compare spark now to what you observed initially. How is the comparison?

 

[Jim in NC]

If your ignition system has a coil check it when it begins running poorly to see if it is extremely hot. A bad coil can cause the problem you are having.

 

[ChasK]

Try a new gas cap? Are the ones on an A vented? running that long could be a blocked vent.

 

[used red MN]

Try a new gas cap? Are the ones on an A vented? running that long could be a blocked vent.

You don’t need to buy a different gas cap. All you have to do is reach up and take the cap off when it starts dying, if it comes back to life that is your problem, you need a vented cap.
Hello TrapperRick, welcome to YT. I am going to go along with what DaveBN has covered in reply 3. My vote is a problem with insufficient fuel delivery.

 

[RTR]

Fuel issue

 

[RTR]

start at the fuel tank outlet and check the flow from tank through sediment bowl and out the line going to carburetor. Make sure it is full flow with no interruptions and will fill a pint mason jar. Then, move forward.

Also, check the spark with an inline spark tester to rule out a faulty switch that allows spark intermittently. I have also seen switches only allow spark when you let off the momentary start position of the switch (full key start switches).