Throttle adjustment

Gordoro · Mar 27, 2012

Farmall A. Just bought this tractor,the throttle lever does not give very much RPM. Also as is common with the lever the notches are worn off on the last quarter. I tried with engine off disconnected the clivis and adjusted it to the max still not enough RPM. Any suggestions? Thanks for your help in advance. Gordon

mkirsch · Mar 27, 2012

The tractor is around 75 years old. Of course there will be severe wear on parts that get moved every time the tractor is operated...

They make replacement throttle quadrants. You can buy them from hundreds of different sources online.

Adjusting the throttle rod won't increase RPM. The tractor has a governor that senses RPMs and adjusts the throttle automatically to maintain a steady RPM.

Technically the "throttle lever" adjusts the governor, and the governor adjusts the throttle.

Here's how you synchronize the throttle to the governor:

1. Turn the tractor off.
2. Push the throttle lever over 1/2 way open.
3. Adjust the linkage to the carburetor so the clevis pin will JUST slip through the yoke to connect everything back up while you're holding the carburetor throttle wide open.

The engine only turns 1450 RPM at full throttle. It may not seem very fast to the untrained ear. You need a tachometer to check RPMs.

If you are not getting full RPMs, you have a problem with the governor.

gene bender · Mar 27, 2012

If the input lever is wobbly it can make bad throttle response they can be bushed to remove the problem. To set linkage with engine off remove the clevis going to the carb then open throttle all the way then adjust clevis holding carb open. Mite want to put a vicegrip on the throttle rod before you try to turn the clevis. Getting the clevis free helps adjusting for the correct length. A local machine shop should be able to rebush the input shaft if not send it to me as i do them all the time.

Gordoro · Apr 4, 2012

Ipulled the carb and cleaned the junk out. I then adjusted the carb to governor clevis. I hooked up a dwell tach. The positive to the grounding screw on the mag and grounded the other end. I got a reading of 700 on the 8 cyl and I then doubled it, should be approx 1400. But I still have a misfire off and on. Not a constant missfire. Seems correct one thing and another pops up. The tractor has been setting for over 3 years so could be a sticking valve? Any way got the RPM"s now onto correcting the misfire. Thanks again.
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Throttle adjustment

Gordoro

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mkirsch

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gene bender

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Gordoro

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