Well theres why it wont start

turns out a harvester mag doesnt get along very well with an allis tractor.

Heres a few things
1)crank and cam are timed perfactially
2)spark on all 4 cylenders
3)it is using a harvester H4 mag

Someone on the allis forum said that my H4 will not work on my B because the impulse does not trip at 3 and 9 like it should. This could explain why the thing has not started.

So...... how do i get the mag to trip at 3 and 9???

Sounds like a job for someone who knows what theyre doing. The mag is off another allis, my old WC. who would i send it to to get this done??

or

im wondering if it would be cheaper to fix my fairbanks mag. part of the base is broke from someone dropping it, and then after i bought it i dropped it again and now theres no spark. Ive got another base half of the mag, i really just need someone to fix it and put it back together......

Lanse if it warms up and dont rain too hard, I will come down this weekend and help you get it going. Richard

Chuck, I told you two months ago that the IH mag has a 35° lag angle and the Allis should have 30° but that's not enough to keep it from running. You say the crank and cam are timed perfectly, well duhh, you have not had the engine apart to mess up the gears. But there is a lot more to timing a mag than sticking the wires in the holes. I gave you explicit directions but for some reason you think that you know better and that you can do it your way. Sorry bud, there is only one right way. And when you time it that way it will run. Now don't get mad at me. I am trying to be your friend but you have to accept the help.

Chucky. There is nothing wrong with your tractor.
You need to time the mag right.
FIRST, (this is simple) Take out the #1 spark plug (thats the one at the front, closest to the radiator) Now with your thumb over the spark plug hole have a friend crank the engine over till you feel air pressure on your thumb, (you might have to try this several times to get it right. Once you start to feel some air coming out, STOP cranking. Now, with a piece of wire or something, (I use a screwdriver or my plier handle) poke in the hole and continue craking the engine SLOWLY. You will be able to tell when the piston is at it's verry top. Grab the fan and rock it back and forth a little to be sure it's at the top. (you might want to take all the spark plugs out so it turns easier) NOW....without moving ANYTHING, Take the distributor cap off. See which way the brass piece on the rotor is pointing. That is where the spark is coming from and it needs to get directed to number one cylinder at this time because it is the one that is ready to fire. (Do you understand how a 4 cycle engine works? ) Four strokes, Intake stroke, as the piston goes down, intake valve opens and fuel mixture is sucked in. Compression stroke, both valves closed, piston comes up and squeezes fuel vapor real tight, when at the top of the stroke spark occurs BOOM, Power stroke piston is forced downward by explosion, (I know you understand that) both valves are closed. Exhaust stroke exaust valve opens as piston comes up and burnt gasses are expelled. The other 3 clylinders follow in like manner. In your case 1,2,4,3. Let's see, now, where was I? Oh yeah, The rotor. Look at that pointer piece. Now look at the cap. Is it pointing toward one of the holes in the cap? close to it? before or slighly after? Slightly after is good. Before will break your arm. Stick #1 plug wire in that hole. (nothing else matters at this point, let's get the tractor running first) Now continue in a clockwise direction and insert the other plug wires, 1,2,4,3 and reinstall the spark plugs. Try starting it now. Unless you have had the magneto apart and messed up the internal timing (very easy to do) it shoud at least try to run.


sounds about like what we did

Well, I see you did read it. Thanks, I'll say no more.

Thanks for posting it!!

Im going to go shove a screwdriver in it and make another video. This is really getting the best of me.

I watched your latest video. You pointed out the plug wires and their respective positions on the cap. It seems to me that the H4 mag would turn ccw not cw. remove the cap and crank it by hand and tell us which direction the rotor turns.

The only reason it is getting the best of you is you STILL aren't listening to all the good advice given you. That tractor WILL run with the IH mag, I have power unit running a 60 combine that has an IH mag actually starts a little easier than the C with FM mag.

Been suggested before, but never answered.

No, an Allis uses a clockwise mag. And no matter what mag you put on it, it's still gonna turn clockwise.

the drive coupling will turn the mag regardless of which way its supposed to go. It snapes clearly, so it has to be going the right way.

Thanks anyway

And if you want to get real confused the H4 does come in CCW versions. They are used on the gas start diesels. But no, that doesn't apply here.

Just like the instructions said is how you did it?Fine,now where is the rotor pointing when you are at TDC?It needs to be a tiny bit past number one.To figure that out,like I said mark the position on the mag where number one is on the cap,but mark it on the mag,pull the cap,is the rotor pointing to the mark,before or past?If its not past,try to turn the mag until its past a little,put the cap back on,wire according to firing order.I would turn the motor over while the cap is off to see which way the rotor turns.When you dont know for sure,never assume anything.If you do this it probably will start with a crank.Now by it being a different mag,if when you check TDC on number 2 cylinder,pull the cap off the mag and if it points to just a little past number 2 on the cap,it should run.It might need some fine tuning,but it should run if you get 2 cylinders on TDC with a rotor pointing past the lug for that cylinder,you have dry plugs and good enough gas it should run.If when you have TDC on number 2 and its pointing somewhere else,you might have problems,but it still might run if you can wire it right.I have never worked on a mag,so I dont know a lot about them,except they do the job of a distributor.Most motors fire at a little before top dead center,which is why the rotor should be pointing a little past the lug.6 degrees out of 360 is not much,but you should be able to see its past the lug.

Somebody correct me if I'm wrong but, I believe if you pull it it should start even if the impulse doesn't work. Maybe not.. Bernie Steffen

Ok guys, i hope this explains everything. i'll do this again tomorrow and remember to get the rotor in there, but here we are with the screwdriver method.

This is just what i did a few minuites ago, i hope i did this right. I really honestly do believe its not the timing, its something else. But hey, ive been wrong before. Thanks for all the help everyone. We'll figure this out!! :-D
new video
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I just had a couple more ideas for you.

Have you checked the compression on all 4 cylinders? In my haste to put the last piston in my tractor I forgot to stager the rings and didn't realize that until I got everything else back together. Low compression will make the tractor hard to start.

Do you have any way to check the rotor timing on your magneto? I spent several months trying to start my Case DC before I traced the problem to the rotor in the magneto. It was off by one tooth. The magneto had just come back from a professional rebuilder so I didn't suspect that would be the problem. The tractor would smoke and backfire, but it wouldn't run. The impulse clicked at the right time, but the spark was out of time by just enough to keep it from running.

I don't know what he has got there, but I tried to put a FM mag on my Farmall B years ago & couldn't get it in time. I had to grind the lugs off the impulse and weld two pieces of key stock about 45 degrees from the old lugs. Then it could be properly timed.I now have the same H4 mag back on it that I took off then. So maybe the allis FM mag has the lugs in a different position than the H4 he is trying to use. Lanse: Make sure to turn it over real slow and if you can see the piston through the spark plug hole, see if the mag snaps when the piston is on top. If not maybe that H4 mag won't work. Please let us know what you find.

is the camshaft timed to the crankshaft correct?

The impulse only works when cranking, pulling in second or third gear you should not hear an impulse click.

Ok if you are certain its not the timing,fine.Where is the carb for this tractor?Why dont you have the carb for this tractor on it?An Allis C is quite a bit bigger of a tractor,maybe its too much gas?If you take a carburetor off of anything,and put it on something else,it will need some adjusting.It might run,but probably not very good.If this carb will work,you might need to clean it up for it to work right.
Now maybe you didnt want to go all into it,and show every bit about the timing,but you still dont show where the rotor is pointing when the number one piston is TDC.You can be at TDC on the exhaust stroke,and have your wire on number one and be half way or 180 degrees out of time.However it didnt sound halfway out when you were pulling it.
Dont get discouraged,If the mag fires the plugs,thats all it has to do.Now it seems you have a lot of room to adjust it,but you can be a tooth off,at least you can on a distributor usually.Maybe you have a slot it fits in,I dont know,but you still might be off a tooth one way or the other.Maybe not if you didnt move any of the gears.Except if you had to put the mag on,are you sure its on in the place it is supposed to be,rotor just past number one lug on TDC?I dont know a lot about a mag,but I know enough about a gas motor to say if that mag is firing the plugs,its probably not your problem.It still is either timing or your carb,or both.So one more time,in respect to your video,you show the plug wires in the right order,good.You show in the other video the piston up(I guess)GOOD!Yet you still do not show the rotor pointing past the number one lug.Ill take your word for it if you checked it,but dont assume anything.If it is in a gear that turns the mag,if its one tooth off,it might not run.Distributors are like that,one tooth,wont usually run,thats how important the position of that rotor is.I dont know much about a tractor like yours.I am not there to see with my own eyes whats going on to have a better opinion.However,in all the years I was a mechanic I have worked on lots of motors with a distributor and on cars they usually have an automatic transmission so you cant pull start them usually.I always got them started by the second or 3rd time I checked the timing.I one time got a motor started on the floor of the shop with a coffee can for a carburetor with holes punched in the bottom of it for a little gas to run through,and it didnt take all day.
Sometimes after rebuilding a motor you can have the valves adjusted wrong and think they are closed,but they actually should be open,and time it to that and be half way out.I just recently worked on a big truck,went to set the valves after changing a head gasket,and the first 2 valves had been adjusted wrong,intake set at exhaust clearance,exhaust set at intake clearance.It ran for a bunch of miles like that.
I dont think you need to choke your motor to pull start it.If you are sure its timed right,hook your choke wide open.Soak a rag with gas and tie it over the carb intake(if you have a fire extinguisher you may want to carry it with you until you see what happens)pull it.It should start fairly quick if everything is right,maybe run 30 seconds or so until it sucks all the gas out of the rag.If that works,you have a carb problem.Thats about as good as I can do without knowing more about whats happening.Be careful.It could suck the rag inside of the motor if you dont do it right.I almost dont want to tell you this,so tie it on there good maybe use a hose clamp or plastic tie so it cant get inside the motor.Probably a good idea to turn the gas off to the carb if you do this with the rag,then if it runs maybe try turning the gas on and see if it will run.Dont sweat it too bad,most people dont get timing right the first time.I didnt,neither has anybody I ever saw try the first time fire it right up.I just helped a kid rebuild the 4 cylinder motor in his Mustang,that doesnt even have a distributor,and he had 2 wires crossed and it wouldnt start,gas filter was plugged too,and he was trying to set the timing on the exhaust stroke which put the cam timing mark 180 degrees out.Looked the firing order up on the internet,changed 2 wires,turned cam half way around,put belt on and fired it up in less than 30 minutes.

The piston is at the top on the exhaust stroke to, are you SURE it was the compression stroke ? Where EXACTLY was the rotor pointing that is #1 terminal ?? Turn by hand until the NEXT impulse snap, the rotor should be just past the terminal for the wire that goes to #2, one more snap=#4, another snap and rotor should be just past the terminal for #3. IS THIS WHAT IS HAPPENING? If that mag worked on the WC it will work on your B.

Trucker,
I too have mentioned mag rotation several times and never been acknowledged, others have given your suggestions but since most of us are so old we have probably forgotten how to time an engine or how to troubleshoot. And a small correction for you, B and C and CA Allis are the same engine (early B was 1/8" smaller bore,but most have bigger sleeves now)

When I seen your video on the ole AC "B" I thought that looked like an IH mag on there.

You ARE NOT answering the question of which way the ROTOR (the part that directs the spark to the cap terminals and then through the wires to the plugs) turns. Some mags are internally geared and the firing sequence is completely backwards to what seems logical.

I watched several of your videos and honestly it seems like the entire firing order may be backwards or something is way off like you said. Instead of pulling it with the kubota have your buddy put his thumb over #one hole till it blows air out while you crank it by hand slowly. Have all plugs out when you do this but have all spark plugs on the wires and grounded so he can watch for the spark. You also need to know which way the rotor is turning. When #1 sparks and his thumb detects air pushing out put the screwdriver in the hole on the piston and roll the engine with the fan belt back and forth gently to be sure it is at the very top. Then pull off the mag cap and see if the rotor is pointing right at the #1 spark plge wire terminal. Then check which cylinder fires next and roll the engine over so the piston on that cylinder is at the top and his thumb gets an Air push and check the rotor and check the wire to see if it went to that hole. I have a gut feeling you have the firing order backwards. If I was closer, I would stop in and have a "look see".

Gary, I know which way an H4 turns. Leave the kid alone

Teddy may be onto something with the drive lug being at enough of a different angle that it might be physically impossible to turn the mag to where it is timed right. YOur guy mentioned 9 and 3. I can never remember which it is but Farmalls are at either 10 and 4 or 8 and 2 at TDC.

Something else I haven't seen mentioned, though somebody touched on it down below is that once you have the motor set up to #1 TDC on compression, that is just to mount the mag with the rotor cocked to fire on #1. (As a side note, if you can mount it that way, you ought to be able to time it -- i.e. 9 and 3 or 10 and for or whatever shouldn't be a problem) To actually time it once it is mounted, you need to turn your motor just exactly 180* so that it is at TDC on #2, in your case, then roll the mag body away from the motor until it clicks and lock it down at that point. There's some slack in the fit between the drive lug on the motor and the driven lug on the mag, and doing it that way takes up the slack to get a good adjustment.

And I know you say your plugs are dry, but it still sounds to me like pulling 1/3 of the way around the house at full choke will flood it. Those motors don't usually take but about two or three full turns of the crank at full choke before they'll start to flood.

The gears in the mag may be setup for counter clockwise rotation instead of CW rotation. Hal
PS: Standard Magneto can rebuild your old mag.
1-800-624-6386

I'm tough, I can take it, so correct me if I'm wrong. It's happened once or twice. ;8^)

My impression was that all H4 mags are the same as far as their gearing. The ones that ran CCW were on the diesels and the 9-series gassers. But I'd thought that the reason they ran CCW was because of the extra idler gear in the timing train which would reverse the direction of the magneto drive from the rest of the letter series. Other than setting up the impulse to click in the opposite direction, I thought they were essentially the same for internal gearing. If the impulse coupler on Lanse's mag were set up for CCW I could understand his not being able to get a spark at TDC for starting, but it ought to fire when being pulled if everything else is in order.

Only other thought is that if his mag did come off a diesel or a 9, and even if the impulse coupler were switched for CW rotation (if that's even possible), those mags were set up to spark at 7* and 15*, far less than the 35* advance of the regular gassers. Still, I should think it would run, even if poorly.

So, I'm all ears and willing to learn. Fire away!

Picture shows the FM mag that belongs on the tractor. I marked the firing order 1-2-4-3. The arrow shows Counter-Clockwise rotaion(viewed from impulse coupling).#1 TDC there should be a mark on the flywheel you can see though the inspection hole on touque tube( I think it's on the left side).To time a impulse mag, remove it from the tractor, turn mag backwords till the rotor lines up with the timing lug.Reinstall on tractor, trying not to move the rotor. If rotor moves a little, you should be able to turn the mag enough to line the rotor back up with the timing lug.

If the mag is turning Clockwise rotaion(viewed from impulse coupling). Just swop #2 wire with #3 wire.

Thanks,I dont know a lot about the old Allis Chalmers,especially with a magneto.I just cant get my mind around if it fires the plugs why it wont run?I think it will run,but I live a couple states away or I would go help him.