184 Cub skips when warmed up

[Charlie M]

My 184 Cub is skipping after it has ran for about 30 minutes. I know a coil going bad can do that and I had that happen a couple of years ago - replaced the coil. The reason I'm asking is I had a new set of points this spring not get installed right and it burned them pretty good to the point I had no spark. I did a lot of filing on them and the tractor now starts pretty good but has also developed the skip when hot I mentioned. My question what happens to points when you file them a lot - can they do what I'm describing. I seem to have gotten the notion from this site if you have to file points much you don't have a good set of points any more. I haven't done any trouble shooting yet such as measuring resistance on the coil or looking at the points again. At the moment I'm just curious about the points and what happened to them.

 

[old]

My 184 Cub is skipping after it has ran for about 30 minutes. I know a coil going bad can do that and I had that happen a couple of years ago - replaced the coil. The reason I'm asking is I had a new set of points this spring not get installed right and it burned them pretty good to the point I had no spark. I did a lot of filing on them and the tractor now starts pretty good but has also developed the skip when hot I mentioned. My question what happens to points when you file them a lot - can they do what I'm describing. I seem to have gotten the notion from this site if you have to file points much you don't have a good set of points any more. I haven't done any trouble shooting yet such as measuring resistance on the coil or looking at the points again. At the moment I'm just curious about the points and what happened to them.

I've file points a good many times and as long as the gap is correct they are just fine for years to come. If the coil is so hot that it steam spit off of it then good chance it is the problem

 

[300guy]

If I was you I would take the points and condenser out and throw them in the emergency box in your shed and put in a Petronix ignition system . No more filing and possibly no more skip. If the distributor shaft has some wear in it, points can jump around and possibly cause the skip. That's what I did 20 years ago and it starts like a new one with no more problems of burning points, corrosion on them from sitting or condensers failing causing a now start. I only have a set of points hanging in my shed for an emergency.

 

[old]

If I was you I would take the points and condenser out and throw them in the emergency box in your shed and put in a Petronix ignition system . No more filing and possibly no more skip. If the distributor shaft has some wear in it, points can jump around and possibly cause the skip. That's what I did 20 years ago and it starts like a new one with no more problems of burning points, corrosion on them from sitting or condensers failing causing a now start. I only have a set of points hanging in my shed for an emergency.

I have never had any luck with those electronic ignitions on a tractor. I have used them on a lawn mower but thrown at least a dozen of them away that had been on a tractor. I have tractor that have had the same point on them for a decade or more and they still fire right up

 

[300guy]

I have worked on small engines, cars and tractors for 59 years and the best thing that ever happened to both mowers and cars was the installation of the electronic ignition systems. I have replace 1000 and 1000's of points and probably have replace 30 to 40 electronic systems in those same same years. Like I said I have been using a Petronic on my tractor for 20 some years and there isn't enough money in the world to get me to put a set of points back in my tractor!!! Every time I went to the farm (every 2 to 3 weeks) and tried to start the tractor, I had to get into the points and clean them before it would start. This is the end of my discussion!!! Do as you want, but for me there is NOTHING better than an electronic ignition!!

 

[old]

I have worked on small engines, cars and tractors for 59 years and the best thing that ever happened to both mowers and cars was the installation of the electronic ignition systems. I have replace 1000 and 1000's of points and probably have replace 30 to 40 electronic systems in those same same years. Like I said I have been using a Petronic on my tractor for 20 some years and there isn't enough money in the world to get me to put a set of points back in my tractor!!! Every time I went to the farm (every 2 to 3 weeks) and tried to start the tractor, I had to get into the points and clean them before it would start. This is the end of my discussion!!! Do as you want, but for me there is NOTHING better than an electronic ignition!!

I've been working on engines since I was around 10 years old and I'm 68 now and if factory installed they are good but I have NEVER found one install on a tractor that wasn't factory that was worth the $$ for them

 

[Janicholson]

My 184 Cub is skipping after it has ran for about 30 minutes. I know a coil going bad can do that and I had that happen a couple of years ago - replaced the coil. The reason I'm asking is I had a new set of points this spring not get installed right and it burned them pretty good to the point I had no spark. I did a lot of filing on them and the tractor now starts pretty good but has also developed the skip when hot I mentioned. My question what happens to points when you file them a lot - can they do what I'm describing. I seem to have gotten the notion from this site if you have to file points much you don't have a good set of points any more. I haven't done any trouble shooting yet such as measuring resistance on the coil or looking at the points again. At the moment I'm just curious about the points and what happened to them.

What happens inside a coil that is failing is that the primary winding turns are contacting one another through varnish insulation that is rubbed through. This short circuit causes the coil to use fewer windings and thus reduces its resistance. As the heat builds more windings touch, decreasing the resistance even more. eventually the heat causes the output spark to be week enough to not fire plugs. AND the lowered resistance can cause excessive amperage through the points burning them out rapidly. A bad coil may test just a little low on resistance when cold, but dramatically low resistance when heated to the point of failure. Jim

 

[wore out]

What happens inside a coil that is failing is that the primary winding turns are contacting one another through varnish insulation that is rubbed through. This short circuit causes the coil to use fewer windings and thus reduces its resistance. As the heat builds more windings touch, decreasing the resistance even more. eventually the heat causes the output spark to be week enough to not fire plugs. AND the lowered resistance can cause excessive amperage through the points burning them out rapidly. A bad coil may test just a little low on resistance when cold, but dramatically low resistance when heated to the point of failure. Jim

A coil with a shorted winding or three doesn't "ring" which greatly reduces it's effectiveness at delivering a HOT spark with a long "spark line" that lights off the fuel charge in the cylinders without a "miss".

 

[K-Mo]

My 184 Cub is skipping after it has ran for about 30 minutes. I know a coil going bad can do that and I had that happen a couple of years ago - replaced the coil. The reason I'm asking is I had a new set of points this spring not get installed right and it burned them pretty good to the point I had no spark. I did a lot of filing on them and the tractor now starts pretty good but has also developed the skip when hot I mentioned. My question what happens to points when you file them a lot - can they do what I'm describing. I seem to have gotten the notion from this site if you have to file points much you don't have a good set of points any more. I haven't done any trouble shooting yet such as measuring resistance on the coil or looking at the points again. At the moment I'm just curious about the points and what happened to them.

Make sure you have the correct coil. Many systems used 6 volt coils with and external resistor. The 184 uses a 12 volt coil with an internal resistor.