Farmall m is a professional starter button burner upper

Hey everyone. Here's a real whopper of a forum post.

First, I'm a newbie at this antique tractor business. I'm a farmboy and I've been around and worked with engines a lot, but I'm not afraid to admit I haven't until now had the pleasure to work with anything larger than a four wheeler engine that needed to be choked. We've used only diesel tractors for the last twenty or so years and nothing before that was as old as this 1942 Farmall m tractor I bought is so I have a little progress yet to make as far as knowing exactly what to do with the choke and throttle to make this tractor start the easiest. I've only started this tractor twice since I got it two weeks ago and I'm still learning how to know what the tractor wants as far as choke and throttle go. Point being, it's still taking me a few tries to get this tractor running, and it looks like I've encountered a problem with my manual starter button possibly as a result of overuse? When trying to start, I had the experience I'll describe below.

Trying to start the tractor one day, I was holding the starter button in and the starter drive suddenly stopped turning the engine over without my having let go of the button. The starter drive didn't slow down first indicating a low battery, it just went from full speed to a full stop just like that. The starter drive didn't disengage from the plywheel until after I let up on the starter button. I just figured the engine kind of kickfired and made it stop or something so I tried again immediately and the same thing happened again. That's when we noticed smoke coming off the back of the starter button. My dad tried pressing the button in briefly and there were sparks coming out of it. We just unhooked the battery just in case something was getting ground out somewhere and went back to the house.

Note that the tractor's battery has been staying pretty low on charge. It's got a new 12 volt aldernator on it but I think the battery may be getting slowly drained somehow either that or this battery has major surface charge. At least that was what I thought in the past, more about that in a bit.

So I went ahead and bought a new manual starter switch from ytmag since they don't cost very much. I kind of figured maybe it wasn't really the starter switch that was having problems but since they're so low priced it really didn't hurt that much to order a new one just in case. I mentioned previously that we have a 12 volt aldernator, but I don't know what the starter drive is.

As far as I can tell, the wires coming from the battery and going to the starter switch, and from there to the starter drive all seem to be in pretty good shape. We put my new starter switch in earlier today after it arrived and decided to just try to run the starter drive for a couple of seconds to see if everything was going ok. Well it wasn't. I had my fingers wrapped around the side of the metal bracket to which the starter switch is bolted, and as soon as I pressed in the button I got lots of heat on my fingers which were very close to the two connectors on the starter switch back there. We tried one more time after dad got in position to watch and it was actually shooting fire out of it. It seems to be coming out of the switch itself, as aposed to just having one of the cables connected to the switch spark, seems to be coming out between them. Hopefully I'm not sitting on two burnt out starter buttons.

Anyway, I'm not sure what could be wrong. Does anyone know what could cause our tractor to be a professional manual starter button burner upper? Say that three times real fast, but only after you answer my question?

Oh, btw, I keep my hand on the starter drive while operating it just in case it gets hot. I want to know right away if I need to stop cranking, only I wasn't expecting to heat up the starter switch and have the starter drive still be ice cold. Say, touching the starter drive while it's in opperation wouldn't be grounding it out or something and causing this would it? That would sure make me feel really smart, lol.

While I'm at it, I have only one terminal on the starter drive. It has a big heavy wire going to it and a really thin one probably 16 gage if I know my gages at all which I don't. They are both on the same bolt, the thin one is on the outside. I can't understand why I need two wires on one terminal. Dad thinks that wire leads to the ignition switch as well as the starter button. Why is that thin wire there? I really can't make sense of it. Especially why it seems to go to the ignition switch too, as trying to run the starter without the ignition switch pulled out still turns the starter drive over as before, I know because I forgot to pull it out once.


Are these starter buttons capable of throughputting 12 volts?


Oh, and I said I'd talk more about the battery. I should buy a new battery for it, because this one doesn't say how many cold cranking amps it has on it but it is a 12 volt battery lol. Anyway, it kept going low on us. We would run the tractor for a while and shut it off and leave it in the shed for a couple of days and then come back out to mess around with the tractor and run it some more. Problem was, we would have a low battery by then, the starter drive would just barely crank over. When we burnt up the starter button we had just charged the battery completely in the garage and put it right back on the tractor again and tried starting immediately. The starter drive ran way faster than before but well you readers of this horribly long post know what didn't work so well. But as I mentioned we unhooked the battery after we fried the starter button the first time just in case it was being ground out. So today when we put in the new button we had to hook the battery up again. The reason I'm saying this is because the battery still seemed to have the same amount of charge as it had had when the first starter button went bye bye, and that was a week later. Do you all think something is actually getting ground out somewhere and draining my battery and possibly the same thing is smoking starter buttons left and right?

Ok, I know, long post. Sorry everyone. I sure like this hobby though and I want to do it as properly as I can manage.

Speaking of proper, today when we cooked the second starter button, just out of interest for you enthusiasts, the engine tried to start after only one compression stroke, in other words, the starter hadn't really even gotten up to full speed before the engine was firing, and I had not closed the choke because I really wasn't actually trying to get the engine running. Now I call that pretty amazing for a 70 year old engine. It always seems to fire off a few cylinder loads, then die, making you have to just keep on starting it a few times over and over until it stays running. Any idea what's going on? The governor is operating at idle, could it be that it's drawing plenty of gas until it starts owing to the fact that the governor would be all the way open but it's losing prime when the governor closes after the engine rpm's reach idle speed causing it to die?

Ok, I wonder if my first post on this forum was like the longest ever posted her or anything.

Well, you must be a pretty good typist anyhow.
Alternators often put a small drain on a battery.
that's why the battery stayed up the week you had it
unhooked. There is a diode you can put in the line
to stop that. I suspect you have a battery ignition
distributor instead of magneto and that's what the
extra small wire coming from your starter is for. As
far as frying switches I suspect those cheap
switches are just that. Cheap.

As far as the two wires to the starter a picture is worth a thousand words, if you have the equipment to do it it is a BIG help. As far as the M dying right after it is started, it is probably just a matter of finding that sweet spot with the choke. I don't know how cold it is where you are at, but here if I were to start my M at 15 degrees it would fire right off. However I have to run it at full or almost full choke for a minute or two and then slowly release the choke as it warms up. Can't help you on the starter button and some alternaters do not charge until they have reached a certain RPM, then they will charge no matter what the engine speed. So you may have to wind up the motor after it gets warmed up to start the charging process. Hopefully somone smarter will read this and offer some better help. greg

Aaron, First of all I do think it is probably the longest post I have seen on this forum if that means anything.
I really hate to get in this thread as there are some exceptional electrical folks who support these issues far better than I can. First, since you seem to have little knowledge about these old Farmalls so I'll just give you some info. you might find useful. First, they were all 6 volt positive ground when built. When they are converted to 12 volt they must be changed to negative ground as that is how the alternators function in almost all cases. That small wire you mention connecting to the starter post is most likely a 12 volt bypass to put 12 volts to the points for a hotter starting spark and your tractor would revert back to 6 volt when the starter button is released if wired correctly. There are some schematics on this site provided by Bob M. which you might find useful but there are others who will most likely jump on this thread and hand walk you through the conversion process. I've converted one Farmall to 12 volts and it is very simple if you follow all the steps and have a good diagram. I think you need to start and review what you have on this tractor first as it is new to you and something simple is most likely your problem. Check your battery and make sure you have the battery hooked up with a negative ground and the positive cable is running to the switch and starter. The original battery cables were size 00 which is quite heavy in size but they can be somewhat smaller with a 12 volt battery. I'm going to let the real electrical folks jump in and walk you through the trouble shooting process as that is not one of my strong suits. Just remember that when your tractor was built they were engineered to be quite simple and aren't very complex but very simple in design. Hope this helps with a little info for starters, Hal.

it sounds to me like your starter locked up because of a worn starter drive or worn ring gear on the flywheel or both that caused you burn up your first switch. you can't buy a good switch anymore. i keep a spare one onhand for our m's.

Aaron, The M I had almost didn't need a choke. I would give it about 1/4 throttle, and full choke, and then crank it. Once it popped, (which only took 3 or 4 revolutions) I'd shove in the choke, and it was running by that time. That worked in all but the coldest (like 0) weather. I put mine on 12 volts, and only had a small to medium (like 550-650 amp?) battery on mine- that's all I felt it needed. And that's all I did need. As far as burning up starter switches? I'd take the starter off, open it up, and clean it up at the very least. If it was to be drawing excessive amperage, I suppose it could fry a starter switch. I haven't had one do that to me, but I have seen sparks off my battery connections before, and every time that happens, it's due to dirty or corroded connections. IMHO. Bad starter drive and or flywheel ring gear could be causing your locking up issues- you'll be able to evaluate their condition once you take the starter off. Good luck! -Andy

The First thing is to determine what is causing
the starter to stop. If there is a short, or bad
bushings in the starter motor, it will drag on the
field windings and draw massive current.
I believe the starter needs to be rebuilt with new
bushings, new (and better design) drive pinion,
new brushes, and a turned commutator.
Any good auto electric shop can do it and do it
well.
The second issue is the extra wire on the starter
motor stud. That wire probably goes to the coil.
It is likely to be a resistor bypass. This allows
the coil to operate on starting voltage while
cranking. If the starter motor is dragging, the
engine would start but not have enough juice to
make the ignition work just as the starter switch
is released. Thus the start and stop situation.
It is needed. The ballast resistor is near the
coil (if it has one). The wire from the starter
should attach to the coil side of the resistor,
and must have a diode in it to prevent voltage
from going backwards to the starter from the
ignition.
The switches are garbage I do not think anyone
here has found a good source of good switches yet.
If it were mine I would use a starter relay out of
a 12v ford from 1962) connect it so it gets full
battery voltage directly to the terminal near the
S small terminal. Hook the S terminal to a #12
wire going to the existing (smoking) starter
button, and hook the other Smoking switch button
to the Battery Positive with a #12 wire. (this
just uses the poor switch for low current control
of the Ford relay. The I terminal of the relay
can be hooked up directly to the coil input
terminal bypassing the resistor without the diode
(no feedback possible).
The last terminal (big) goes to the starter stud.
(the Small wire there is no longer needed)

If your alternator is a three wire setup, it
should be left alone (but tested)
If it is a one wire setup, or if that pesky wire
goes to the alternator. Let us know and we will
get that operating correctly as well.
Jim

You have gotten some pretty good advice here so
far. That extra wire is probably indeed a bypass
to the ign for feeding battery voltage to ign when
using the starter. You will have a resistor some
where in the circuit , most likely at the coil
itself to reduce voltage when running. If not some
one has wired it poorly. You will also be able to
start the engine without turning the ign switch on
as switch is not required to run starter. Far as
the starter switch itself, well, they are very
poor now day, but , usually work ok on 12 volts.
It is with the six volts which have to carry more
current that they give a lot of problem. But, back
to the switch, where is it mounted. I find that
many on the M are mounted in such a way that when
you push the rod, or pedal, what ever you have ,
it does not push straight onto the button and
therefore deforms the switch and causes even more
problems. I dislike that set up so much I mounted
my switch on my own M in the same position that
the H uses, up on the light post and push it by
hand. Now this works good with 12 volts, but if it
was six you might better want your foot to stomp
it good and hard. That is the reason IH put them
down below for the foot in the first place, just
they did a poor job of making sure it pushed the
switch straight. I have altered a lot of them
switchs over the years for better operation. You
can tell real easy if your starter is working by
just hooking jumper cables directly to the starter
input terminal and ground on frame using a known
good battery and good cables.

My 3- Super C's, 3-Super H's,300 and a previous M are all tuned
such that they start immediately, with no choke, unless it's cold or
they've sat for awhile. All are 12v with alternators.

I suggest you do a thorough check of the engine starting with a
compression test all should be over 100 psi and within 10 psi of
each other. Then check your fuel,fire, and air systems. It may just
need some maintenance.

You never could get a good pushbutton starter switch for an M. The switches were never designed to handle the kind of Amps it takes to start an M.

I would start by removing the starter and give it a good cleaning new brushes and maybe bearings. They get all carried away cause engine doesent start good so jump in and go to 12v that will fix all. Now if the starter has been serviced and you have good cables from battery to sw then to starter and a good ground your problems will probably go away. Stands to reason if the starter is in bad shape the current draw when starting will be greater than the sw likes to see.

Hi.

Thanks for all these replies. I'm just going to print this off so me and my dad can read this advice while actually looking at the tractor to see if we can understand what everyone is getting at.

To the person who said it would be a good idea to get to know what all is on the tractor and understand it better, I agree completely and I intend to do that as much as possible. I'm really interested in this anyway so I'm not going to have any trouble with that suggestion for sure. I just wish it wasn't parked so far away from the house. Maybe I should get my mom to park her trail blazer out in the driveway so I can put my precious tractor in her garage bay. Think she'd agree to that? Lol. That's one problem I have actually. This is a very well restored tractor with fresh paint and a very clean engine. New decals on the sides of the hood, and speaking of the hood it's really smooth to the touch just like a new car. I've had my hands all over the tractor and the only place I'm getting them oily is on the bottom of the engine. I've noticed some engine oil clinging to the bottom right where I'm pretty sure the cluch is. The sides are really nice and clean. It hurts a little just to leave this tractor sitting in the open shed. Sure it's got a roof over it but it's getting dusty and it's getting damp in a big way. I notice lots of moisture on the underside of the gas tank. I hope the points don't give us trouble just on account of it being wet.

Thanks again for all your replies. We're going to take these suggestions and run with them. I'll be sure and post results.

Btw, this is a pull tractor. That is, the guy I bought it from, who restored it, built it up just for pulling. That's also why I bought it. My dad and I have always wanted to get into this pulling thing, and I thought it was time I bit the bullet. I want it to do a good job on the sled so you better believe I want to get to know how everything works on it. It has a 450 carborator. We're told that's awfully big and that we need to be pretty easy on the choke if we don't want to completely flood it out. The guy who had it before is supposed to have adjusted the timing and everything. I know when it runs it's a very nice and loud running engine with a straight pipe exhaust. It's really peppy, once it's warmed up if you give it lots of throttle the responsiveness is pretty impressive. I'm pretty proud of it, at least after it starts anyway .

Oh, that reminds me. Can anyone tell me whether the timing on these tractors is advanced when more throttle is given? If that is so, I believe I might do a little better to increase throttle to around a quarter or so when trying to start the tractor to get it to burn hotter, hopefully making it start easier. I sure don't want to choke it too much at a higher RPM though. I'm told that's a great way to get it to draw way too much gas and give you major flooding problems.

Ok, thanks again.

A good timing setting for pulling WILL NOT start very easy, especially in cold weather. I would say most Farmalls don't need choke or just a little to get started.

My SMTA would probably not start today (30 deg F) if I tried. With that though, it finished 1st in 7000# and 2nd in 7500# points in 2010.

You need to buy and install a 12 volt solenoid (or 6v solenoid on a 6v machine). Those manual starter switches can't handle the current flow of a starter. I went through 3 manual switches in a summer before I installed a solenoid. Been fine for 4-5 years since. I was able to tuck it up between the battery and the starter switch. Now the start switch is used to energize the solenoid and the solenoid handles the heavy starter current.

You indicate that it is a pulling tractor, that
kind of changes a lot of things. It may be pretty
high compression, timing, who knows where it is
set at, no doubt for maximum power under pulling
conditions. Far as the spark advance, that occurs
with engine rpm and totally dependent on how
distributor is calibrated. In other words, it will
advance the spark as engine rpm increases and
retard as it decreases and has nothing to do with
the throttle setting when engine is not running. I
fought 6 volt starting systems for years. The last
really hard starting gasoline engine IH made was
the first 450 gas tractors. About half way through
production they switched to 12 volt systems and
problem solved. Many M's are on 12 volts now and
most stayed with the 6 volt starter and it
works out quite well. One thing, they do not have
the initial torque to get that engine started
turning, but once it turns just a little, they
spin it like heck. Being a six volt starter it
has much lower resistance so will really draw a
heavy current for a few seconds until it gets it
turning. This is normally not a problem but with a
higher comp engine and cold thick oil it may very
well be a problem. You may want to get that
starter converted to 12 volts also if it is not.
Far as solenoids, well, if you can get a really
heavy one it is good, but most of them are no
heavier in the contacts than the original push
switch, just that they slap the contacts together
good and hard. You of course need good clean,
heavy connections all the way through and ground
the battery right on starter mounting bolt for
best results.

I would first try dragging it to start, thus saving the cost of switches, till I got used to starting it. This will also save on battery strain.
Now once you get used to the starting procedure for your tractor. The starter should be looked at as suggested. Then follow the rest of it out till you find the issue.