"Project Bantam" - brass ring gear reproduction

Bob Weaver in Shelby, Ohio had a batch of reproduction brass ring gears made.  During Bob's own restoration he needed one as well, and I was fortunate enough to obtain the second-to-the-last one he had made.  The Weaver family were very pleasant folks and I enjoyed doing business with them.  The gear looks like good quality American workmanship.  That kind of workmanship is worth it, and it didn't come cheap.

"Project Bantam" - magnamatic ignition

I came across this article in Gas Engine Magazine, and I'm certainly glad I did.
http://www.gasenginemagazine.com/gas-engines/cheap-fix.aspx
The author showed how to fit a common B&S coil to the Magnamatic Ignition on this model FB engine. The concept is simple. Remove enough material from the core to make it fit under the flywheel. And it is tight.

Original Coil

After some careful hacksaw work and filing, and I think it turned out rather well. I did not use a hoseclamp like the fellow in the article. I fashioned two spring clips to emulate the original ones. I made them VERY tight, and also put a screw on one side to positively locate the coil along the shaft axis, as an added measure to make sure it doesn't wander around due to vibrations.

Modified Coil

Modified Coil and Core assembly

"Project Bantam" - gearbox teardown

The axle shafts on the gearbox were flopping around in their bushings, so I knew there was going to be some parts replacement inside.  I just didn't think it would be this bad.  I was told that the brass ring gear had been repaired once before.  That didn't console me much either, since I knew it was probably bodged back together.  My father didn't have a lathe at the time, so the previous repair would have been dodgy.

 

Opening the cover on the gearbox revealed a lot of sludge, but no broken parts.  It all came apart easily by following the overhaul instructions.  The back of the shift shaft was a little rusty, so that had to be addressed before the shift fork would come off.  Otherwise the bearings look relatively good, and I took note of the part number on the input shaft seal.  "Victor 62012", which is supposed to cross over to "Federal Mogul 470954".  The axle shaft seals were so bad, I couldn't even read them, they're supposed to cross over to "Federal Mogul 254287".

The gearbox wasn't a problem, it came apart easily from the differential.  The worm gear pulled out without any problem and showed some wear.  Opening the differential showed the horror of the main failure.

It seems a lot of the teeth had dissolved into sludge.

The spider gears look ok.  They don't seem to have any significant wear.

Cleaning everything out was a several hour process.

 

The axle bushing is obviously broken off causing the excessive wear of the teeth.

I doubt this gear salvageable, I supposed I must obtain a new (different) one...