1978 Briggs and Stratton Generator Ignition Problem

[TheSensibleHuman]

I have this 1978 B&S Generator (M: 326435 0296-01) that I unbolted off of a trailer bought from a scrapyard. This thing was all rusted and beat up, and clearly didn't run, but I wanted to see if there was any way to restore it.

First I removed the flywheel cover and the engine cover and blew out all the debris: the leaves, mud, and rat nests that clogged around the flywheel. I checked the spark plug, and it seemed to be in decent condition. It looked like It was replaced recently.

I then tested the magneto. That thing was rusted and honestly looked terrible. I pulled the flywheel a few times, but there was no spark coming from the spark plug. I also pulled a few times with my hand directly over the spark plug, and there was not even the slightest shock.

So I figured the magneto was bad. After taking the old magneto to a local engine parts store, and ordering a new one, I attached the new magneto, and made sure to leave the gap between the magnet at .010".

Thanks to the electric motor mounted to the side of the engine, and geared flywheel, I hooked up a set of jumper cables from a lawnmower battery to the motor and was able to engage the electric start. I grounded the end of the spark plug while connected to the magneto, and flipped on the electric starter hoping to see a spark. And there was a spark... Well, kind of. It was a very inconsistent spark, and would sometimes spark and sometimes wouldn't.

I have read multiple forums where people suggested checking the strength of the magnet, as a weak magnet would produce a weak spark. I'm not exactly sure what is weak or strong though. My magnet will attract the end of a screwdriver from 1" - 1 1/2" away.

Then I read that this issue could be the condenser. But... after removing the flywheel, I realize that there is no condenser—or if there is one, I have no clue where to look. I was assuming that If it had one, It would be behind the flywheel. But I didn't see any cover or anything to unbolt.

I took a bit of fine-grit sandpaper and sanded the rust off of the magnet, hoping that would make a difference. It didn't.

If this helps, I also cleaned out the carburetor thoroughly, removed the crud from the combustion chamber, drained and replaced the oil, replaced the air filter, and fuel line.

I have repaired many small engine fuel problems before, but this is something I don't have as much experience with.

If anyone would give me some pointers, I'd be appreciative. Everything looks great internally, I just can't figure why the spark is weak.

Thanks.

 

[ILENGINE]

The points and condensor would be external on that engine. Most likely on the side of the block under a rectangular cover for the points, with the condensor mounted close to it.

 

[TheSensibleHuman]

Are you talking about this? I did take that box off but it didn't look like there was any condenser. There is this plunger that sits behind that red rubber cap, I don't know if that is anything.

 

[ILENGINE]

Looks like somebody has converted the points to an atom module. The points should be disconnected and there wouldn't be a condensor at this point Do you have a picture of the new module. I am just thinking the new module could have the electronic module built in and you no longer need the atom module. or anything on the side of the engine connected to that point box.

 

[TheSensibleHuman]

By module, are you talking about the atom module? I didn't replace it or have a replacement. Are you suggesting that the atom module needs to be swapped out with a new one? Or are you referring to the magneto or something?

 

[Romore]

The module could be bad, replace it if suspect.

 

[tom3]

I wonder if a standard Briggs coil with the built in module could be found that would fit (or could be made to fit) the mount on the old motor? Sure solve a lot of problems if so..

 

[ILENGINE]

I wonder if a standard Briggs coil with the built in module could be found that would fit (or could be made to fit) the mount on the old motor? Sure solve a lot of problems if so..

I wonder if the 398811 will work. It is for the after 81 cast iron block engines even though his is the before 81 engine.

 

[TheSensibleHuman]

This is the coil I currently have attached. So you're suggesting that I should try the 398811 model? Since this ignition coil will replace the points and condenser, would it guarantee a better spark?

Thanks for the input. I really appreciate it.

 

[ILENGINE]

I don't know if it would give you a better spark, but I am also thinking that your module is installed backwards. Need to take it off and turn it over.