farmall m not ruuning well

[ducky 55]

I have been having trouble with my m running poorly, so I put in new points, condenser, plugs and wires. It still seems to have a miss in it. Today when I was using it it got worse, missing and running poorly with very little power. I increased the throttle and it got worse with the missing and little power. Anyone have any ideas on what could be the problem? Thank you.

 

[used red MN]

Are you gutsy enough to disable one cylinder at a time to
check if one or which cylinder is the culprit? Pull the spark
plug wires out of the cap one at a time and place them
back in with a light push so the are not completely seated
in the cap terminals. Now at an idle grab the spark plug
wire an inch or so back from the cap boot a pull it out to
see if there is any change B when the spark is removed
from that cylinder. Check each one by one. Another you
should do is run it up to temp and set the or check the
valve clarance. 0.017 in. hot Tight valve with no clearance
can cause a miss. Compression check would also be wise.

 

[gene bender]

First thing always is a compression check before throwing money at new parts better do one now

 

[caterpillar guy]

You can also just short out the plug with a screwdriver for the same test. It will have to completely short out the spark to a good ground though. I have done both that and just pulled the wire off the plug and short to ground for the instant.

 

[teddy52food]

That is a good way to ruin the coil. Ground the plugs instead.

 

[Turkeyfoot]

Have you ruled out fuel supply problem?
I'd check fuel flow at carb to make sure
you're not starving for gas. If you can
take the fuel line off before the carb or
remove plug from bowl you should have
steady flow. If only a trickle then
that's a problem. They can plug up where
the tank drains into the sediment bowl,
where fuel line enters carb or if someone
has put an inline filter on that has
become clogged.

 

[used red MN]

Teddy, in a purely ideal world and based on electrical theory yes it is not good for the coil. However, I have seen and personally used this method on old standard voltage Kettering ignitions as an old tractor would be equipped with hundreds of times. I have never seen a coil needing to be replaced after this was done. Nor have I seen them fail shortly thereafter. I have seen those type of systems driven many miles with a plug wire with lost continuity and one cylinder not firing. Fix the bad wire and they go on there happy way. In fact next to the hard parts in the distributor I would almost say that the coil was the 2nd most reliable part of those ignition systems. Of course I am talking about systems with quality USA built parts. Now as for later high energy ignition systems, yes I practice grounding the lead to the cylinder I want to check. Raising the field that high in those coils is not good and that high voltage flying around everywhere with sensitive electronics nearby is also a bad idea. As for Cat guy and grounding the wires at the plugs, less and less of these tractor have the original style 90 degree bare terminal ends that can be easily shorted as you said. So instead of adding something that that poster will just scratch his head over I explained it a way that could be used for any configuration.

 

[Janicholson]

Diagnose first. Does it have good solid blue spark? Is there powerful suction on the carb air intake when cranking? Is there slop in the distributor
shaft? Is there a pint a minute fuel out the carb drain port? Then compression, then valve adjust, then further analysis. Jim

 

[the tractor vet]

A HOT valve set is really any temp above 70 Degrees F

 

[ducky 55]

(quoted from post at 09:18:35 08/15/21) A HOT valve set is really any temp above 70 Degrees F

checked the plug wires and there was spark on all the wires when i pulled them from the distributor cap. There also was as good flow of gas out of the carb. I did notice the distrutoer shaft wriggles from side to side. Is that normal? I ran it today and it missed and after about 45mins. of use it missed and sputtered so bad I barely made it back to the shed.Any ideas why it got worse when i was using it? Thank you for all the valuable suggestions.

 

[ducky 55]

(quoted from post at 17:00:57 08/15/21)

(quoted from post at 09:18:35 08/15/21) A HOT valve set is really any temp above 70 Degrees F

checked the plug wires and there was spark on all the wires when i pulled them from the distributor cap. There also was as good flow of gas out of the carb. I did notice the distrutoer shaft wriggles from side to side. Is that normal? I ran it today and it missed and after about 45mins. of use it missed and sputtered so bad I barely made it back to the shed.Any ideas why it got worse when i was using it? Thank you for all the valuable suggestions.

I went out tonight and pulled each plug wire from the cap and reinserted a little and then pulled the wire from the spark plugs one at a time, Number 4 cylinder was the only one that killed the engine when pulled.It seemed like the engine ran a little bit better when I just started to put the plug wire back on the plugs or in the distributor?? I also ran the gas out of the carb and got about 3/4 of a pint in 1 minute. Does anyone have any suggestions? Thanks again

 

[Janicholson]

The reason the engine picked up a bit with part pulled plug wires is that the added gap the spark jumps actually fires the plug. It needs new plugs or
cleaned and gapped old ones for sure. The flow is OK to the carb. The wiggle in the distributor is not good. The wiggle prevents accurate setting of
the points, and changes dwell and timing radically as it flops around. It can be rebushed, or buy a rebuilt one (sold here on YT store) Jim

 

[kossuth]

DITTO on the shaft wobble. All kinds of things get thrown outta wack when things start flopping around. Advance, retard, dwell, etc. GOTTA straighten that out before you do anything further..... Whether you rebuild the existing (personally I would do this) or get a replacement that's up to you but you gotta fix that first.

 

[rustred]

check compression and record the psi. that is always the first thing you do when encountering engine problems. the other thing u can do is
see if it will run on one cyl. at a time is you have no tester. these engines will run on only one cyl if the valves are good. so once
compression is comfirmed good then you go to the next step. plus its always good to run a valve setting , like who knows when they were last
set. common procedure.

 

[gene bender]

Why are you putting off the compression check if you dont have good compression it will never run good

 

[ducky 55]

(quoted from post at 04:28:35 08/16/21) Why are you putting off the compression check if you dont have good compression it will never run good

Good morning Gene. I don't have a compression tester. I'm going to look for one today? Do you know why the engine wanted to die when i pulled the wire on #4 cylinder and not the others?Thanks.

 

[kevinj54]

(quoted from post at 08:09:26 08/16/21)

(quoted from post at 04:28:35 08/16/21) Why are you putting off the compression check if you dont have good compression it will never run good

Good morning Gene. I don't have a compression tester. I'm going to look for one today? Do you know why the engine wanted to die when i pulled the wire on #4 cylinder and not the others?Thanks.

Maybe ya have the firing order wrong???

 

[BarnyardEngineering]

(quoted from post at 05:09:26 08/16/21)

(quoted from post at 04:28:35 08/16/21) Why are you putting off the compression check if you dont have good compression it will never run good

Good morning Gene. I don't have a compression tester. I'm going to look for one today? Do you know why the engine wanted to die when i pulled the wire on #4 cylinder and not the others?Thanks.

Because the #4 cylinder is the only one firing properly.

 

[ducky 55]

Well I did a compression test tonight with #1 at 125, #2 at 125, #3 at 120, and #4 at 115. Anyone have a suggestion on what to do next, replace distributor shaft, check valves,different plugs? I have spark to each plug but it will not start. I'm at a total lose on what to do. Also is the compression numbers good?

 

[kossuth]

(quoted from post at 20:53:20 08/17/21) Well I did a compression test tonight with #1 at 125, #2 at 125, #3 at 120, and #4 at 115. Anyone have a suggestion on what to do next, replace distributor shaft, check valves,different plugs? I have spark to each plug but it will not start. I'm at a total lose on what to do. Also is the compression numbers good?

hat's pretty good assuming its a relatively stock motor. If your dizzy shaft is flopping around in there it aint gonna run right. You gotta get that sorted out. Don't worry about firing order or any of that other BS. The shaft shouldn't have any runout on it at all (side to side/up down movement). There can be some endplay (movement in and out) but any runout in the shaft can HUGELY vary your timing events.

 

[Rich'sToys]

Since you have good spark this may not be an issue, but sometimes a bad coil will work fine when it's cold, but then start to act up when it gets warmed up.

 

[ducky 55]

(quoted from post at 21:34:43 08/17/21)
Since you have good spark this may not be an issue, but sometimes a bad coil will work fine when it's cold, but then start to act up when it gets warmed up.

Would you recommend buying a complete distributor or would i need just the bushing and washer kit? And what is the difference between a IH and a Delco distributor?

 

[Janicholson]

Well the answer depends on your skill as a pin punch user to remove the gear, and your ability to drive out the old bushing, and install a new one with
accuracy. Some shafts are also so worn that a new bushing is little help. If the kit has a shaft great. Jim