Allis C Missing/Wont Stay Running

Bobby (MI)

New User
I need some help with my C. I have tried everything. It will start and run at idle but you can hear a little miss. As soon as I put it under power it starts missing really bad and stalls. It is distributor ignition.

When I was checking the timing tonight, the timing light would intermittantly not light every few revolutions, so obviously it is not firing all the time. The "Fire" mark was also jumping back and forth in the observation hole

I have changed the coil, condenser, plugs, wires, rotor, cap, and updated the wiring.

Before I decided that it is likely an electrical issue, I swapped to a known good carb and drained the gas and put fresh in.

Any thoughts?

Thanks.
 
Probably in the distributor. Take the plate off that the points are mounted to and see if the advance weights are rusted fast. You should be able to take hold of the rotor and move the advance below the plate. Points that are dry on there pivot pin will also make it skip fire. The advance plate not being free will cause the fire line under the timing light to jump around or engine speed being to low to hold the advance over.
 
You say you changed every thing but the one thing you may should have and that is the points. One like that could be bad points or bushings in the distributor and you need to check the gap on the points at ALL 4 lobes so as to be sure they open and close as they should at all for places. Of course throwing parts at the problem before you know where it is, is a good way to cause more problems
 

I would check to be Certain that the Plug wires are installed in the proper firing Order, just to be SURE...
2 switched can cause that kind of problem...

FWIW...!

Ron.
 
Thanks for all the advice guys. I forgot to mention that I also replaced the points recently and that did not cure the problem but I think I can remove that off the list of things to check.

I removed the distributor last night, pulled the plate and checked the advance weights. They did have some rust on them and they started working better when I cleaned them and lubed them. I also oiled all the bearing areas and lightly greased the cam lobes and put the assembly back together. I checked the gap at all 4 lobes and it was OK. But I realized that when I do a final tightening on the set screw, the points opened more than they should. I don't ever think I checked them after I tightened the screw last time. My guess is that the gap could have been too wide, so the distributor was firing sporadically.

It was raining cats and dogs so I didn't take the tractor out and run it last night. Maybe tonight. If this doesn't fix it, I need to figure out a way to check the runout on the distributor shaft to see if the bearings are okay. It didn't seem like there was much play at all in the bearing, but it doesn't take much to put it out a few thousanths.

Thanks again for the advice.
 
Sand the bottom of the points assembly to roughen the plating for a good ground.Good points are getting harder and harder to find.JB.
 
So after lubing the distributor weights and making sure they were free, oiling the distributor bearing areas, lightly greasing the cam lobes, and confirming that the distributor bearings okay, I put the whole unit back together I fired the tractor back up.

I confirmed that the timing was spot on at about half throttle. The tractor ran rough for a few seconds and then smoothed right out. I was able to mow for 10-15 minutes and then it started missing again.

I had to re-start in 3-4 times to get back to the shop. As I said in my previous posts, I have pretty much changed everything that delivers fuel and spark. But in this instance it seems to have broken down as it warmed up...could it be a bad condensor or coil even though I replaced them? Any other thoughts about what to check?
 

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