Thanks Eddie---would you have any info on the Model FM--j4a11 that i have? figures i would try the simplest things first and that would be to clean the points before i remove it--I took the cap off and the rotor but could find no points in there

Hi Dan,
old croak has what you need yet again--the sheets show a flange mount but that can be swapped for a plain end and so the OEM could use the under body bolt style mount-- data for both mounting styles would be the same.

oldcroak.com/fmj-series-1942-bulletin-2856a/

Most mags that old croak have kindly loaded on their site are listed down the left hand column.
It is well worth while perusing a lot of the Advertising sheets loaded as several will tell you the OEM's and what tractors or engines they were used one engines.

oldcroak.com/f-m-special-magnetos-confused-yet/

Cheers,
Eddie B.

That Old Croak website is excellent Eddie, I'd never heard of it before, the good thing is he owns old Cats himself and talks about the different mags used on old Cats, very interesting.

In there Eisemann talk about the RT-4 back in 1939 in advertising material as being a smaller mag and suggested for engines up to 4" bores, a lot of good info .

Thanks again for leading us dummies into the light, you are going to need shoulder replacement surgery soon from carrying us all, particularly those tightwads too tight to even buy a Operators Manual for their old Cat.
All the best
Mike

"bruce wrote:

oldcroak.com/eisemann-cm4-ct4-magneto-instructions/

Thanks for the link Bruce, it's got a lot of really good info.
All the best
Mike

dpendzic, Just as a note, the mag on my brothers 15 is an American Bosch MJC4C-104. I think there are lots that will fit. Old Croak told me which ones he considered the hottest, but I dont recall right now. Any luck on your 15 yet? Grant.

Thanks GrantJ---yes there seems to be quite a few as my owners manual shows an Eisemann---right now the machine is 200 miles away, but I am reading thru the literature that Eddie posted on the Fairbanks-Morse and when I get back up there in June will clean the points and see what i get