Cat fifteen magneto

Move this to the discussion forum so people will see it.

The magneto that you have is an Eisemann model G4. It is either a 1st or 2nd edition but I can not tell with only a picture of the distributor end. The mag that you should have is an Eisemann model GV4 with an IS6 impulse coupling.
The G4 will work, but it would be nice to make sure that they lag angle on the impulse is correct and to have a fixed spark ring on the points. The carbon brushes can be purchased from most any magneto rebuilder. I think I used Mainely Magnetos for my last couple of coil rewinds, http://www.mainelymagnetos.com/, but there are others out there that would be happy to help.
One trick that can help on these mags is to make sure that they points are clean. Depending on what the points are made out of (tungsten or platinum) they can corrode quite quickly under certain conditions and stop the mag from working.
Thanks
ken

You are time and money ahead to just buy a new manifold while they are still available IMHO. There is nothing much left to work with the one you have and most others are not much better you will find from parts. The double walled design makes it more difficult to refurbish an old one as well. They used the exhaust flow to warm the intake air to reduce icing in cold temps, and for example on the 22's (close close tractor, successor to the big 15) they had the distillate option which needed more heat in the engine to properly burn the fuel. Those uses the dual wall manifold as well as a valve on the exhaust to adjust how much exhaust heat to flow through the intake manifold. Of course those all rusted up over time as expected.