JD A Questions

[Mnethercutt]

Howdy folks, two simple, unrelated questions for other A owners out there.

First, from an operator standpoint, how do you know what RPM to set the engine at when using the PTO? I'm used to running a tractor with a tachometer and want to make sure I don't overspeed the implement. Any advice appreciated. I know its probably a dumb question but nobody I know has run these tractors other than in parades so some of the knowledge of how to use them in the field is lost around here.

Second, does anyone have the dimensions for the choke rod? My tractor is missing the rod completely (probably rusted away) so its a chore to start the tractor. Specifically looking for the diameter of the rod and ideally the length so that I can fabricate a new one.

For reference this is a styled 1950 JD A.

Thanks!

 

[ET]

The choke rod is 1/4"

 

[620 John]

I can't remember for sure but I think all A's full throttle rpm under no load is 1050 rpm. Rated RPM is 975. When you set the full throttle no load rpm to about 1050 the governor should maintain approximately 975. In order to set the RPM you need a photo tach or handheld mechanical tack pressed against the clutch pulley cover.

In addition, being it's a late A, that engine tends to respond better to throttle lever adjustments because of the way the spring and governor arm is mounted on the shaft. It seems like older unstyled and early styled A's where the governor spring and arm are attached together on the left side of the shaft respond sluggish and slow.

I ran a friend's late styled A in the field plowing one time and he had the throttle stop bolt adjusted all the way in because he would go tractor pulling with it. I got on there not realizing this until I got the plow in the ground and opened the throttle. I thought wow this thing has some guts to it. Engine started getting pretty warm after one round. Then I realized where the stop bolt was adjusted to..... Probably should have realized right away based on the sound of the engine.

My Unstyled A feels like a dog when you throttle up. Even if you adjust the stop bolt in more for more rpms, you get it in the field plowing the governor maintains a nice steady rpm and good lugging capability.

 

[Rich'sToys]

The choke rod is 1/4"

You should be able to stretch a tape measure to get the length. Add enough for the 90 degree bend at the carb end and enough at the other end for threads to screw the knob on.

I'd go out and measure my '52, but we got a foot of snow last night and I'm not inclined to go out and battle that right now!

 

[flying belgian]

Howdy folks, two simple, unrelated questions for other A owners out there.

First, from an operator standpoint, how do you know what RPM to set the engine at when using the PTO? I'm used to running a tractor with a tachometer and want to make sure I don't overspeed the implement. Any advice appreciated. I know its probably a dumb question but nobody I know has run these tractors other than in parades so some of the knowledge of how to use them in the field is lost around here.

Second, does anyone have the dimensions for the choke rod? My tractor is missing the rod completely (probably rusted away) so its a chore to start the tractor. Specifically looking for the diameter of the rod and ideally the length so that I can fabricate a new one.

For reference this is a styled 1950 JD A.

Thanks!

We used to push it all the way forward and then pull it back a wee bit to run the New Idea picker. Pa had one of those Stewart Warner hand tachs he put on the pto one time and determined that's where it needed to be for 540.

 

[Rodney51Cub]

The choke rod on my A is 49" long plus an inch for the bend. I have the 18 gallon tank and the choke rod is mounted to the light bar.

 

[Rich'sToys]

The choke rod on my A is 49" long plus an inch for the bend. I have the 18 gallon tank and the choke rod is mounted to the light bar. View attachment 106478

My '52 is set up the same as Rodney's. I measured mine today. It is the same as his.

 

[Fixingfarmer]

Well as oversimplified as it sounds wide open throttle if you aren’t going down big hills is fine. It’s only got a 540 setup so it’s difficult to overspeed the implement. Pullers also like to speed up Gs engine rpm especially so the likely hood of an engine problem is fairly low unless you meet that hill. I have always ran the three point mower and the auger full throttle both on the unstyled B and the 52 A. Would I love a 530 with a tachometer? Sure but it’s gonna be ok. Also that late A with the creeper will run a 7 foot rototiller so pto implements around here are fair game.