Available now from Restoration Supply Company is this coupling that allows you to time a magneto infinitely. The center bore of the hub comes with a 1/2" bore to be adapted to your application. The dog drive on the front side fits a standard magneto impulse drive adapter. There is a worm gear inside that is adjusted by the two hex-drive shoulder bolt at the top. The hub is then clamped and locked in position by the socket head cap screw at the bottom. This coupling allows you to time a magneto with a timing light and adjust as you see fit. The body is 2 ½” diameter. The body measures 11/16” face to face and the hub protrudes 5/16”. Made in the USA of brass, bronze and stainless steel. Restoration Supply will have them at Hershey.
Thanks for looking,
Appears to be a copy of the Bosch adjustable Oldham coupling. Glad there is something on the market to replace it, as the Bosch coupling has been out of production for many years.
I have seen this, and it is beautifully made. It is robust, and operates like it was produced by watchmakers. I plan to get one or more.
Another great product from Restoration Supply Company.I have some homespun versions of this on a couple of my cars, but they don't look like this. I'll be buying a couple or more of these! Thanks for posting this. It's great that we have businesses like Restoration Supply Company to help keep these early cars on the road.
Is this piece generic and can be used on any Magneto?
I have a Bosch DU4 mag that I'm using on the speedster.
Yes it would work with any magneto. This has been a long project. I needed a coupling for installing a more modern magneto with impulse drive on an EMF and necessity is the mother of invention, so I designed this. This picture is the prototype installed in the EMF. I've driven the EMF about 1000 miles with the coupling so far. The production version is a bit thinner, hence more versatile.
Thanks for everyone's kind words!
Great Job, solves so many problems! I saw this coupling in operation and it is QUALITY.
Just to clarify things here. The coupling mounts on the shaft of the magneto drive- not on the magneto shaft itself. The tangs on the coupling engage a slotted disc that in turn engages the tangs on the magneto impulse. If you don't have an impulse on your mag, you will need a coupling of sorts with a tapered bore and tangs to fit the intermediate slotted disc. Hope this helps a little.