Farmall A - firing order [hooking up missing plug wires]

gdtractor

Member
Got a Farmall A - Plug wires all gone!! Mag is intact! When I hold my finger over the #1 cyl. and it pushes my finger out - where the rotor is pointed is #1 right or 180 off? but it is slightly BEFORE the plug wire hole - is that still #1 ? (no mechanic but learning - thanks !) [youtube is not much help - ha!] #1 is the cylinder closest to front right? firing order .. 1,3,4,2 ... #1 appears to have the rotor position .. just past the bottom of the distributor - so is #1 [ON DISTRIBUTOR] before or after where the plug wire comes in? I am probably as CLEAR as mud .. sorry . :) Thanks! Gary
 
Make a mark on the body where the #1 tower is then remove the cap and see where the rotor is pointed it should be where the mark is. If not remove the outer cover and move the gear so the rotor is pointed at that mark. You can leave the cap off and turn engine over to double check rotor position when it snaps. With the plug out you can feel compression and see the rotor snap.
 
Your rotor should be at the number 1 plug tower, that's about one o'clock with No1 piston at TDC on the compression stroke near the radiator. Hal

2-1
4-3 Firing order as the rotor rotates CW.
 
Compression will push your finger off the hole BEFORE the piston hits TDC. You need to shine a light down in the spark plug hole after your finger gets blown off and visually ensure the piston is at the top of its stroke.

A/B/C engines are nice because you can visually see the piston at TDC through the spark plug hole.
 
UNLESS SOMEONE HAS REMOVED & PUT THE DISTRIBUTOR BACK "INCORRECTLY"
the wires should be: 2 1
3 4
or very close to this position.
 
Sorry; my attempt at showing the position of the wires did not come across the way I planned.
#1 should be in the upper right hole as you look sitting in the seat.
 
Gene, Please quit telling people to screw up the gear timing that way. If that tractor ran before the wires were removed, it will run again when they are replaced. That mag sparks when the points open. The rotor gears are marked so that when they are in time, the spark will happen when the rotor lines up with the contact in the cap. If the rotor is not timed right, the spark has to jump a huge gap in the cap.
 
Sending to several responders .. i appreciate the help SOOOO much ..
Gary

YOu are EXACTLY RIGHT >> I shined a flashlight down on the cylinder and turned the engine on #1 cylinder to the TOP .... and the distributor rotor is exactly on the upper right (#1 ) ...
Now ... the bottom right from sitting ON THE SEAT would be #3 and bottom left would be #4 correct?
Top left would be #2 ? right?

THANKS So MUCH !!!!
Gary
 
Sending to several responders .. i appreciate the
help SOOOO much ..
Gary

YOu are EXACTLY
RIGHT >> I shined a flashlight down on the cylinder
and turned the engine on #1 cylinder to the TOP ....
and the distributor rotor is exactly on the upper
right (#1 ) ...
Now ... the bottom right from
sitting ON THE SEAT would be #3 and bottom left
would be #4 correct?
Top left would be #2 ?
right?

THANKS So MUCH !!!!
Gary
 
Sendin this to others .. .. thanks for the help !! .. you guys hit the nail on the head !!! I used the flashlight to shine inside .. and turned the engine on #1 cylinder to the TOP .... and the distributor rotor is exactly on the upper right (#1 ) ...
Now ... the bottom right from sitting ON THE SEAT would be #3 and bottom left would be #4 correct?
Top left would be #2 ? right?

THANKS So MUCH !!!!
Gary
 

IT WORKED !!!
Sending to several responders .. i appreciate the help SOOOO much ..
Gary

YOu are EXACTLY RIGHT >> I shined a flashlight down on the cylinder and turned the engine on #1 cylinder to the TOP .... and the distributor rotor is exactly on the upper right (#1 ) ...
Now ... the bottom right from sitting ON THE SEAT would be #3 and bottom left would be #4 correct?
Top left would be #2 ? right?

THANKS So MUCH !!!!
Gary
 
your advice worked !!
I have not gotten the carb on or tried to "fire" it yet .. but everything was in place when I placed the #1 cyl UP all the way ..
thanks so much ..
Gas line tomorrow and wires .. and hopefully will be RUNNING >.
Again ... thanks !!!
 
When you have to find No1 piston at TDC on the compression stroke hold a thumb over the plug hole
while a helper slowly cranks the engine until you feel pressure against your thumb. Then drop a long plastic straw on top of the piston. Then you watch the straw rise as a helper slowly cranks the engine. When the straw quits rising No1 piston should be at TDC on the compression stroke. Hal
 
You time your mags on the A and Bs however you like but thats the way i do mine and several others been doing it that wy for a long time and they start like new. Remember he has a mag not a dist.
 
Gene; I am not here to argue, but anyone that works on mags will time the gears on the marks and leave them alone. The diesel mags get timed on the A mark , The rest are timed on the C or clockwise mark. The small gear has 2 teeth with the edges beveled & the mark on the big gear goes between them to be right. This puts the rotor in line with the contacts in the cap when the points open and spark happens.
 
I don't think Gene realizes mucking around with the rotor timing doesn't change the timing of the SPARK at all.
 
If this advice was not out there given by several people I would have never gotten my M started again. Rebuilt the mag with the best parts from 3, rebuilt the carb & cleaned the fuel system. With the gears lined up correctly the rotor was half a post off. Moved the small gear one tooth which made the rotor right on #1. Timed it and it fired first time and runs great. I guess I could have bought a new more correct mag but I didn't. mm
 
If the rotor doesent line up with the tower when it fires how is the spark going to get to the plug. I have 8 h-4 mags and do repair them for others just mite be lucky then getting them to work and start and run you are saying
 
El Toro .. got things lined up and the wires on etc ..
Got the manifold and carb in the mail .. going to put them on tomorrow .. hopefully I will try and start it tomorrow ....

The plugs are different than any I have seen .. they are 1" instead of 7/8" ... ha !!

Hoping it will .. and hoping I won't have to move the mag much to get it exact ..

Just an update ..

Gary
 
Hi again .. (sending to several to make sure I get it right - ha!)
Okay.. I thought I had the mag on okay - BUT the top bolt was out and bottom loose.

So I just guessed and with the proces above . the rotor was pointing near or at #1 cylinder. After getting carb and manifold on .. etc .. and new gas line etc ..
I tried to start it by pulling it a little ways it did fire .. a few times .. no consistent - and not very often ..
Now I am wondering if I omitted getting the timing correct when I put it back ..
Question-what is the basic rule to set the timing if everything "looks good" as I explained before.

I didn't look at the points or anything yet so this may be a premature question! does it have a condensor ? can I test the coil .. I am getting spark but not sure if it is out of time or if spark is intermittent ..

What would you suggest ? Please .. Gary
PS .. the carb flooded twice when I was pulling it .. later the neighbor pulled me about a half mile .. thx Gary ..

Farmall A ...
 
Hi again .. (sending to several to make sure I
get it right - ha!)
Okay.. I thought I had the mag on okay - BUT the
top bolt was out and bottom loose.

So I just guessed and with the proces above . the
rotor was pointing near or at #1 cylinder. After
getting carb and manifold on .. etc .. and new
gas line etc ..
I tried to start it by pulling it a little ways it
did fire .. a few times .. no consistent - and
not very often ..
Now I am wondering if I omitted getting the timing
correct when I put it back ..
Question-what is the basic rule to set the timing
if everything "looks good" as I explained before.

I didn't look at the points or anything yet so
this may be a premature question! does it have a
condensor ? can I test the coil .. I am getting
spark but not sure if it is out of time or if
spark is intermittent ..

What would you suggest ? Please .. Gary
PS .. the carb flooded twice when I was pulling it
.. later the neighbor pulled me about a half mile
.. thx Gary ..

Farmall A ...
 
Showing this to more than one - LOL
Okay.. I thought I had the mag on okay - BUT the top bolt was out and bottom loose.

So I just guessed and with the proces above . the rotor was pointing near or at #1 cylinder. After getting carb and manifold on .. etc .. and new gas line etc ..
I tried to start it by pulling it a little ways it did fire .. a few times .. no consistent - and not very often ..
Now I am wondering if I omitted getting the timing correct when I put it back ..
Question-what is the basic rule to set the timing if everything "looks good" as I explained before.

I didn't look at the points or anything yet so this may be a premature question! does it have a condensor ? can I test the coil .. I am getting spark but not sure if it is out of time or if spark is intermittent ..

What would you suggest ? Please .. Gary
PS .. the carb flooded twice when I was pulling it .. later the neighbor pulled me about a half mile .. thx Gary ..
 
(Sending to several to make sure I get it right - ha!)
Okay.. I thought I had the mag on okay - BUT the top bolt was out and bottom loose.

So I just guessed and with the proces above . the rotor was pointing near or at #1 cylinder. After getting carb and manifold on .. etc .. and new gas line etc ..
I tried to start it by pulling it a little ways it did fire .. a few times .. no consistent - and not very often ..
Now I am wondering if I omitted getting the timing correct when I put it back ..
Question-what is the basic rule to set the timing if everything "looks good" as I explained before.

I didn't look at the points or anything yet so this may be a premature question! does it have a condensor ? can I test the coil .. I am getting spark but not sure if it is out of time or if spark is intermittent ..

What would you suggest ? Please .. Gary
PS .. the carb flooded twice when I was pulling it .. later the neighbor pulled me about a half mile .. thx Gary ..

Farmall A ...
 
More info: .. when I cleaned the mag ... I forgot to mark the position.. butI polished up all connections .. I noticed after I put it back together the pressure stroke on #1 cylinder that the rotor now pointed to the postion where #3 was so I put #1 plug wire there .. and then clockwise went with the firing order.. 1 3 4 2
Got a REAlly GREAT spark now!!! But haven"t tried it yet .. hoping it will work . Gary
 
With a magneto the rotor will not line up until the retard mechanism has released. Otherwise it will stop before getting to the correct position. You should hear the retard click as it releases.

If you rotate the engine backward the rotor will line up correctly since the retard will not work while rotating backward.
 
Here is a video of the tractor running - after many years of sitting outside under a tarp ..
still needs some TLC .. on pushrod [not bent but sticking .. ] This start was from cranking not pulling ..
http://youtu.be/cNjK3xj89o0

Thanks for your help!!

Gary
 

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