Ignition System for a 6 HP Fairbanks-Morse

1 HP Hercules

Content Tools

8204 Gordon Lane Hermitage, Tennessee 37076

Being a newcomer into antique gas engine collection and repair, I would like to share an idea about an ignition system for a Fairbanks-Morse. My first engine was a 1? HP Hercules with a Webster low tension ignition. When I found the engine, it had been buried in the ground approximately 20 to 25 years. After 6 months of work, it is restored and running properly.

I have a particular interest in old engine ignition systems. I bought a 6 HP Fairbanks-Morse with the ignition missing. After some phone calls, I found out that it was supposed to have a magneto with a flipper actuated by a roller sticking out of the cam gear.

Not knowing what it looked like, I saw a picture in Hit and Miss Enterprises' catalog. Seeing that it had springs to impulse it like the Webster ignition impulses, was enough to start the wheels turning in my head.

I first played with the ignition button on my gas grill. I had decided that even though it might work, it would not be dependable. I found a chain saw with solid state ignition. Temporarily hooking up rubber bands to the flywheel to impulse it, I found out that it would not turn fast enough to produce a spark.

Looking around some more, I came across a Homelite XL12 chain saw. It had points and a condenser in it. After hooking up the rubber band again, I got a spark when impulsing it by hand. I knew that I was on the right track.

I started to work. After discarding the cylinder, piston, and rod and cutting the crankshaft in two between the main bearing and chain clutch, it began to look less like a chain saw and more like something else. I cut off all the excess metal from the engine block. To lighten the flywheel, I cut off all excess metal, leaving the hub and two magnets. This left it looking like a piece of pie.

A kill switch was made from a strip of brass and installed above the coil.

An adjustable bracket was fabricated and installed from the back of the block to the top of the coil bracket. This gives support to the coil and provides a means to adjust the coil to flywheel air gap. Again, after digging into my scrap box, brackets for springs to impulse it were made. At this time I made a trip to a hardware store where I got two springs. As the magneto is very efficient, I selected two weak springs (only one spring will give a spark, but it looks better with two). A base plate was made from ?' aluminum to bolt in the same holes that the original fit. Necessary brackets were made to mount the magneto to the base plate. Quarter-inch key stock was used to make the flipper rod. Timing was set by cutting the flipper rod to the necessary length. After some paint, it was installed on my engine.

It performs well, looks good and I'm proud of it.

Another version that I made has one spring in the back installed vertically. It's more compact and easy to adapt to different applications.

Anyone wanting more information, give me a call and I will be glad to help any way that I can. My phone number is (615) 889-2624.