1946 Farmall Model A

[prverschneider]

Good morning all, new to the forum with a new to me 1946 Farmall A. Has some issues, hoping some of you can point me in the right direction.

Tractor is 6V, positive ground. Electric start, 2 headlights, one rear light. Generator, voltage regulator.

1st issue, very hard starter. Carb is fresh, rebuilt by Carfolo. New plugs, wires, coil, condensor, cap, rotor, points. Everything is clean and tidy. Good spark, timing set with #1 cylinder top dead center. When it does start, runs great, but it does not like to start, cold or hot. Points set at .013, I have heard that with electric start they should be set at .020. No idea if that is true or why it would matter. Air cleaner is cleaned, fresh oil. 100 psi in all 4 cylinders, no stuck valves. Any ideas would be appreciated. Is the timing adjustable? The mag can be rotated a bit clockwise or counterclockwise by the looks of it, maybe it's to advanced or retarded on start up?

2nd issue, wiring on the voltage regulator is not all hooked up. Regulator has 4 tabs, F, BAT, L, and one underneath that is unlabeled. Generator has 2 studs, A and F. Looking at wiring diagrams A stud should go to Gen, which I take to be the tab underneath the regulator. F stud should go to F tab, but only without electric start and lights, otherwise it should be unconnected, is that true. BAT goes to the ammeter, which I have with the 4 position switch. Where does L go? Don't know if the switch works as I'm not there yet. Definitely not charging the battery as I have to keep that on a tender. Not sure how it even charges the battery as one of the wires from the switch goes to the starter, not the battery, others go to the lights. Switch looks like it is wired correctly based on diagrams I have seen.

Any insight would be greatly appreciated,
Pete

 

[560Dennis]

I recommend you get this it manual from YT or your farm store.
the ..02 gap is for distributors.
please define hard starting ?
do you have a vom meter ?
clean your grounds good make sure your have heavy duty battery cables .
im going recommend doing a voltage drop test first before doing anything , guessing cost lots of money and time , don’t recommend rushing off and getting 12 volt , I got 6 volts on my C and they start fine.
So let’s get you going

 

[used red MN]

Hello Pete, welcome to YT! Short on time at the moment for a lengthy response. Do you have a magneto or a battery powered “points and coil” distributor ignition? The mag points set at .013” and the “battery powered ignition” points set at .020”… period. There is a process to set/check the timing for both that I can’t go into at the moment. If you answer my above question that will help others who want to chime in.

 

[rustred]

Good morning all, new to the forum with a new to me 1946 Farmall A. Has some issues, hoping some of you can point me in the right direction.

Tractor is 6V, positive ground. Electric start, 2 headlights, one rear light. Generator, voltage regulator.

1st issue, very hard starter. Carb is fresh, rebuilt by Carfolo. New plugs, wires, coil, condensor, cap, rotor, points. Everything is clean and tidy. Good spark, timing set with #1 cylinder top dead center. When it does start, runs great, but it does not like to start, cold or hot. Points set at .013, I have heard that with electric start they should be set at .020. No idea if that is true or why it would matter. Air cleaner is cleaned, fresh oil. 100 psi in all 4 cylinders, no stuck valves. Any ideas would be appreciated. Is the timing adjustable? The mag can be rotated a bit clockwise or counterclockwise by the looks of it, maybe it's to advanced or retarded on start up?

2nd issue, wiring on the voltage regulator is not all hooked up. Regulator has 4 tabs, F, BAT, L, and one underneath that is unlabeled. Generator has 2 studs, A and F. Looking at wiring diagrams A stud should go to Gen, which I take to be the tab underneath the regulator. F stud should go to F tab, but only without electric start and lights, otherwise it should be unconnected, is that true. BAT goes to the ammeter, which I have with the 4 position switch. Where does L go? Don't know if the switch works as I'm not there yet. Definitely not charging the battery as I have to keep that on a tender. Not sure how it even charges the battery as one of the wires from the switch goes to the starter, not the battery, others go to the lights. Switch looks like it is wired correctly based on diagrams I have seen.

Any insight would be greatly appreciated,
Pete

good morning, without knowing where the carb is set ot the timing it has to be one or the other or both. you say you sett he points to.013 so i am presuming you have the magneto. you refer to electric as .020 so yes the electric distributor as you call it is .020 and yes the timing is adjustable,.. but once its set to the factor setting there is no need to play with it. you can verify the timing by removing the number one plug or all of them for ease of engine turning. get the number one coming up on compression and have the spark plug grounded and easy to see the spark. have someone crank the engine as slow as they can and watch the spark. the instant it sparks which i use a wire to feel the piston coming up to tdc and you can feel the piston right at tdc and have it spark at the same time. that is where u tighten the magneto and done. easiest way with a mag. due to the impulse snap retarding the spark. you can also look at the timing marks to verify its correct. as for the carb who knows where the main jet is set ? or is the choke working? and how you are going about starting it. i know all these engines start right up in 2 revolutions. you didnt say what u are doing to start it or how much cranking.. first is to pull out the choke push starter button and as it fires push choke in and running. in cold weather they may want to sputter or stall so just pull choke out and in and good. carb is always the last thing to set , timing is first always. dont know how its starting either, starting from being flooded or being lean ?

 

[Janicholson]

Good morning all, new to the forum with a new to me 1946 Farmall A. Has some issues, hoping some of you can point me in the right direction.

Tractor is 6V, positive ground. Electric start, 2 headlights, one rear light. Generator, voltage regulator.

1st issue, very hard starter. Carb is fresh, rebuilt by Carfolo. New plugs, wires, coil, condensor, cap, rotor, points. Everything is clean and tidy. Good spark, timing set with #1 cylinder top dead center. When it does start, runs great, but it does not like to start, cold or hot. Points set at .013, I have heard that with electric start they should be set at .020. No idea if that is true or why it would matter. Air cleaner is cleaned, fresh oil. 100 psi in all 4 cylinders, no stuck valves. Any ideas would be appreciated. Is the timing adjustable? The mag can be rotated a bit clockwise or counterclockwise by the looks of it, maybe it's to advanced or retarded on start up?

2nd issue, wiring on the voltage regulator is not all hooked up. Regulator has 4 tabs, F, BAT, L, and one underneath that is unlabeled. Generator has 2 studs, A and F. Looking at wiring diagrams A stud should go to Gen, which I take to be the tab underneath the regulator. F stud should go to F tab, but only without electric start and lights, otherwise it should be unconnected, is that true. BAT goes to the ammeter, which I have with the 4 position switch. Where does L go? Don't know if the switch works as I'm not there yet. Definitely not charging the battery as I have to keep that on a tender. Not sure how it even charges the battery as one of the wires from the switch goes to the starter, not the battery, others go to the lights. Switch looks like it is wired correctly based on diagrams I have seen.

Any insight would be greatly appreciated,
Pete

Welcome to YT forums and ASAP parts!
The point gap for a magneto, is .013". The mag should make a clean clicking noise when cranking.
The battery needs to show 6.3 to 6.35 volts when not running, fully charged. Less than 6.5 after charging is not likely good.
Battery cables should be O-gauge, with copper about 3/8"dia.
Timing is set to trip the mag impulse at TDC. on #1 cylinder (Front) at the end of the compression stroke. It then changes timing to advance.
The choke should usually be used for initial cranking of no more than one engine revolution, then opened (pushed in fully),or feathered to keep it running.

The F terminal is not connected on that tractor if it has a cutout not a regulator. Yours has a regulator (4 terminals). The light switch wire going to the generator should be disconnected at both ends and taped. The regulator now controls the field circuit. The first two light switch positions will now be "lights off" not L or H. The L terminal on the regulator should attach to the light switch with 10 gauge wire, where the power goes in from where ever it is now, which is not correct with a 4 terminal regulator. The light switch is divided into 2 separate components internally. one is lights bright/dim, and needs power to operate from the L terminal, the other 1/2 of the switch is for the field control when using a cutout NOT yours. The generator Field needs a ground to function. This ground should come only from your F terminal on the regulator. the light switch body provides this ground when it is used as a generator control (not yours). John T (a major contributor here) has a charging system check list that works wonders. Jim

 

[prverschneider]

I do have a service manual for the Model A, it's a reprint, but covers just about everything. Hard starting would be described as just cranking on it for seconds at a time with no attempt at firing. Acts as if it has no spark, or no gas. Both issues have been addressed as when the tractor came to me it had no spark at all and the carb and tank and sediment bowl were full of junk. Everything now is either new or rebuilt. Tank was emptied and cleaned. It has fuel and it has spark, and every once in a while, she'll start right up after the 1st or 2nd revolution and runs fine. Has brand new battery with brand new cables of the correct gauge, contacts on everything have been cleaned to shiny metal with a Dremel tool and wire brush. I do have a volt meter. Starter is also brand new as the old one needed a rebuild. Thats why I was wondering if it was a timing issue on start up. I've heard it retards the timing some 30 degrees on start up, maybe I'm not quite right on that?

 

[prverschneider]

good morning, without knowing where the carb is set ot the timing it has to be one or the other or both. you say you sett he points to.013 so i am presuming you have the magneto. you refer to electric as .020 so yes the electric distributor as you call it is .020 and yes the timing is adjustable,.. but once its set to the factor setting there is no need to play with it. you can verify the timing by removing the number one plug or all of them for ease of engine turning. get the number one coming up on compression and have the spark plug grounded and easy to see the spark. have someone crank the engine as slow as they can and watch the spark. the instant it sparks which i use a wire to feel the piston coming up to tdc and you can feel the piston right at tdc and have it spark at the same time. that is where u tighten the magneto and done. easiest way with a mag. due to the impulse snap retarding the spark. you can also look at the timing marks to verify its correct. as for the carb who knows where the main jet is set ? or is the choke working? and how you are going about starting it. i know all these engines start right up in 2 revolutions. you didnt say what u are doing to start it or how much cranking.. first is to pull out the choke push starter button and as it fires push choke in and running. in cold weather they may want to sputter or stall so just pull choke out and in and good. carb is always the last thing to set , timing is first always. dont know how its starting either, starting from being flooded or being lean ?

It is a magneto, should have mentioned that. I'm pretty sure I have the time set correctly as when it does start, it runs very well. However, I will go check it again. I went the way have having the rotor pointing at #1 when the impulse snapped. I may be off enough to hinder the starting. I am using the electric start, not the crank. However, I do have the crank and will check it that way. See my reply to another member as to the hard starting.

 

[BobTx]

A two for one. Way back when my Dad bought a un-styled JD A model well used. Very hard starter, when hot would not start (still have back problems from trying to start it). Later Dad borrowed a neighbors F-30 that at idle had a dead miss. Neighbor said to just run it wide open . At full throttle it ran great . The problem with both turned out to be manifold gaskets. Might be worth a check. Good luck. BobTx

 

[prverschneider]

It is a magneto, should have mentioned that. I'm pretty sure I have the time set correctly as when it does start, it runs very well. However, I will go check it again. I went the way have having the rotor pointing at #1 when the impulse snapped. I may be off enough to hinder the starting. I am using the electric start, not the crank. However, I do have the crank and will check it that way. See my reply to another member as to the hard star

good morning, without knowing where the carb is set ot the timing it has to be one or the other or both. you say you sett he points to.013 so i am presuming you have the magneto. you refer to electric as .020 so yes the electric distributor as you call it is .020 and yes the timing is adjustable,.. but once its set to the factor setting there is no need to play with it. you can verify the timing by removing the number one plug or all of them for ease of engine turning. get the number one coming up on compression and have the spark plug grounded and easy to see the spark. have someone crank the engine as slow as they can and watch the spark. the instant it sparks which i use a wire to feel the piston coming up to tdc and you can feel the piston right at tdc and have it spark at the same time. that is where u tighten the magneto and done. easiest way with a mag. due to the impulse snap retarding the spark. you can also look at the timing marks to verify its correct. as for the carb who knows where the main jet is set ? or is the choke working? and how you are going about starting it. i know all these engines start right up in 2 revolutions. you didnt say what u are doing to start it or how much cranking.. first is to pull out the choke push starter button and as it fires push choke in and running. in cold weather they may want to sputter or stall so just pull choke out and in and good. carb is always the last thing to set , timing is first always. dont know how its starting either, starting from being flooded or being lean ?

Timing is dead on. Spark at the snap on tdc cylinder #1. Points are set at .013 so I'm correct there also. Carb was just completely cleaned, and rebuilt. Everything is brand new except for the carb body itself. Mine is the Marvel Scheble without the adjustable main jet. Pretty much can adjust idle speed and air/fuel mixture. You mention carb timing. What is that? Choke works, throttle works. When it does run, it runs great. Just doesn't want to start.

 

[prverschneider]

A two for one. Way back when my Dad bought a un-styled JD A model well used. Very hard starter, when hot would not start (still have back problems from trying to start it). Later Dad borrowed a neighbors F-30 that at idle had a dead miss. Neighbor said to just run it wide open . At full throttle it ran great . The problem with both turned out to be manifold gaskets. Might be worth a check. Good luck. BobTx

If I get it started, Ill spray them down with some starter fluid, see if things change.

 

[prverschneider]

Welcome to YT forums and ASAP parts!
The point gap for a magneto, is .013". The mag should make a clean clicking noise when cranking.
The battery needs to show 6.3 to 6.35 volts when not running, fully charged. Less than 6.5 after charging is not likely good.
Battery cables should be O-gauge, with copper about 3/8"dia.
Timing is set to trip the mag impulse at TDC. on #1 cylinder (Front) at the end of the compression stroke. It then changes timing to advance.
The choke should usually be used for initial cranking of no more than one engine revolution, then opened (pushed in fully),or feathered to keep it running.

The F terminal is not connected on that tractor if it has a cutout not a regulator. Yours has a regulator (4 terminals). The light switch wire going to the generator should be disconnected at both ends and taped. The regulator now controls the field circuit. The first two light switch positions will now be "lights off" not L or H. The L terminal on the regulator should attach to the light switch with 10 gauge wire, where the power goes in from where ever it is now, which is not correct with a 4 terminal regulator. The light switch is divided into 2 separate components internally. one is lights bright/dim, and needs power to operate from the L terminal, the other 1/2 of the switch is for the field control when using a cutout NOT yours. The generator Field needs a ground to function. This ground should come only from your F terminal on the regulator. the light switch body provides this ground when it is used as a generator control (not yours). John T (a major contributor here) has a charging system check list that works wonders. Jim

Mag points are good at .013. I get spark at TDC on #1 cylinder at the click. Battery shows 6.5V . Battery cables are new and correct size.
F terminal on generator is now connected to F terminal on regulator. A terminal on generator is now connected to the terminal on the bottom side of the regulator that does not have a name. BAT terminal on regulator is attached to the ammeter correctly according to the diagrams. Only thing left is the L terminal on the regulator. Some diagrams show that going to the bottom of the 4 position switch, some do not show an L terminal at all. Should mine go to the switch or should I not have one at all?

 

[Janicholson]

The mag impulse is the device that causes the retardation to TDC. The L terminal should be the only connection to the lights through a 15 amp fuse, using a 10 gauge wire. Jim

 

[560Dennis]

manu Of points put an oxidation pro tection coating on the point to keep them in inventory to protect. Take a business paper card and rub it between the points to like clean the oof real good With contact s with the spring pressure on the card. try that .

It is a magneto, should have mentioned that. I'm pretty sure I have the time set correctly as when it does start, it runs very well. However, I will go check it again. I went the way have having the rotor pointing at #1 when the impulse snapped. I may be off enough to hinder the starting. I am using the electric start, not the crank. However, I do have the crank and will check it that way. See my reply to another member as to the hard starting

also is the magneto coil originally? I had issues with old coils , also had issues condenser. The wires inside the magneto ,had them with the fiber insulation that I didn’t trust any more I’ve changed them out.
i don’t recommend the starter method Of timing in your manual is the procedures. timing Processing using the steps out lined .

 

[560Dennis]

The spark at the plugs should be a blue crisp light.
For reference I have a spark plug spark gage that the spark jumps from point to point I set it to jump 3/4 inch.
on the magnetos I have
Another test I recommend is remove the 1/8 inch pipe plug from the intake manifold and install a vacuum gage . Your tractor should have from 18 to 21 inches of steady vacuums at idle. If not you can adjust the idle screw till you do .
if the move irratic then you have another issue to resolve .

 

[rustred]

Timing is dead on. Spark at the snap on tdc cylinder #1. Points are set at .013 so I'm correct there also. Carb was just completely cleaned, and rebuilt. Everything is brand new except for the carb body itself. Mine is the Marvel Scheble without the adjustable main jet. Pretty much can adjust idle speed and air/fuel mixture. You mention carb timing. What is that? Choke works, throttle works. When it does run, it runs great. Just doesn't want to start.

CARB TIMING ..., no such thing where did i say that.? i said u set the timing FIRST, the you set the carb LAST. you didnt answer my questions either so how am i to know where to go next.?

 

[teddy52food]

The spark at the plugs should be a blue crisp light.
For reference I have a spark plug spark gage that the spark jumps from point to point I set it to jump 3/4 inch.
on the magnetos I have
Another test I recommend is remove the 1/8 inch pipe plug from the intake manifold and install a vacuum gage . Your tractor should have from 18 to 21 inches of steady vacuums at idle. If not you can adjust the idle screw till you do .
if the move irratic then you have another issue to resolve .

3/4 inch??????????????????????????????????

 

[teddy52food]

Good morning all, new to the forum with a new to me 1946 Farmall A. Has some issues, hoping some of you can point me in the right direction.

Tractor is 6V, positive ground. Electric start, 2 headlights, one rear light. Generator, voltage regulator.

1st issue, very hard starter. Carb is fresh, rebuilt by Carfolo. New plugs, wires, coil, condensor, cap, rotor, points. Everything is clean and tidy. Good spark, timing set with #1 cylinder top dead center. When it does start, runs great, but it does not like to start, cold or hot. Points set at .013, I have heard that with electric start they should be set at .020. No idea if that is true or why it would matter. Air cleaner is cleaned, fresh oil. 100 psi in all 4 cylinders, no stuck valves. Any ideas would be appreciated. Is the timing adjustable? The mag can be rotated a bit clockwise or counterclockwise by the looks of it, maybe it's to advanced or retarded on start up?

2nd issue, wiring on the voltage regulator is not all hooked up. Regulator has 4 tabs, F, BAT, L, and one underneath that is unlabeled. Generator has 2 studs, A and F. Looking at wiring diagrams A stud should go to Gen, which I take to be the tab underneath the regulator. F stud should go to F tab, but only without electric start and lights, otherwise it should be unconnected, is that true. BAT goes to the ammeter, which I have with the 4 position switch. Where does L go? Don't know if the switch works as I'm not there yet. Definitely not charging the battery as I have to keep that on a tender. Not sure how it even charges the battery as one of the wires from the switch goes to the starter, not the battery, others go to the lights. Switch looks like it is wired correctly based on diagrams I have seen.

Any insight would be greatly appreciated,
Pete

Are you looking at the timing marks on the flywheel when you say it fires at TDC? They are hard to find. when you get the piston close to TDC look for the marks in line with a bolt holding the pressure plate on. If the timing is right, try starting my way. Leave the switch OFF. Open the hand throttle about half way. Close the choke tight shut. Hit the starter & bump it over one or two compressions. NO MORE! Open the choke, turn the switch on and hit the starter. It should pop off instantly. If not the mag may need work or the plugs are bad. They should be gapped at .025 for a magneto. Let me know! Thanks.

 

[DaveBN]

Are you sure the choke butterfly is closing all the way? For testing I would leave the bottom cup off of the air cleaner to be sure it's getting air into the carburetor. Have you checked the valve lash? If not you should do that. There is a very specific method to correctly set the timing. Position the top of the magneto as far towards the engine as it will go. Then get the timing marks lined up. Then with the rotor trying to turn towards number 1 on the distributor cap rotate the top of the magneto away from the engine until you hear the impulse click. Then tighten the bolts securing the magneto.
There is a carburetor timing to the governor that needs to be checked. With the engine not running Set the throttle lever at full throttle. Then remove the pin or bolt for the clevis where the carburetor rod connects to the governor arm, that is on the carburetor side of the engine. Pull the rod from the carburetor fully forward and adjust the clevis until the bolt or pin slides in easily. Now the governor linkage is set correctly. Believe it or not I have had this adjustment affect starting. Also be sure the carburetor linkage moves easily and is not binding.
This engine should start within one full revolution if everything is in good shape.
Dave

 

[prverschneider]

Update. Wiring is now correct. Have lights working, ammeter reading, and battery charging when I get it running. As to getting it running, turns out it is not currently an ignition issue. It certainly was with no spark but that was rectified a while back with all new parts. Something is going on with the governor. When shut off and throttle lever in idle position, the throttle butterfly at the top of the carb should be in a wide open position. It is not, it stays closed. There is no pressure on the carb rod, you can flop it back and forth. If I hold it so that the butterfly is in the wide open position, tractor will fire and run immediately. Once if runs, I let go and the governor takes over and it goes back to idle rpm. From there, I can run it thru the gears, drive it around, everything is fine, governor works as it should. Just saw DaveBN's post. I will try that tomorrow and see if something is out of adjustment. Thanks for all the help and insight. More to follow.

 

[prverschneider]

CARB TIMING ..., no such thing where did i say that.? i said u set the timing FIRST, the you set the carb LAST. you didnt answer my questions either so how am i to know where to go next.?

I'm new to this forum thing. Replied to your post itself. Said timing was good, and you had said this at the beginning of your post "good morning, without knowing where the carb is set ot the timing it has to be one or the other or both." I took that to mean there was something to do with "timing" the carb. No idea what you meant so I asked. DaveBN posted something along those lines so I will look into that tomorrow.