I was asked yesterday if the Eisemann GS-4 and RT-4 could be used on old Cats and I couldn't find the info even after a search through old threads on here, I thought I had the full list of mags used on the early Cats but I can't find it, I suspect my puter ate it, it does that sometimes, photo's and files just disappear to the ethernet, I try and print off useful scans everytime someone generously uploads them but stuff get's put somewhere so safe even I can't find it.

Does anyone have the list of Cat tractor and their original / appropriate magneto they can please upload?
Thanks
Mike

Hi Mike,
YEP, things seem to be spirited off for sure.
Hope these help.
Kindly supplied by other contributors in the past and saved for such times--people need to do this more often than they do as one day some of us that have saved this useless info will not be here to help out.

Cheers,
Eddie B,

EDIT--
add this list courtesy of oldcroak magneto-will keep searching as should you on this site, it is a gold mine.
And a few more using Google

oldcroak.com/caterpillar-magneto-aplication-info-1947/

www.oldengine.org/members/diesel/magnetos/Magdata6.htm

Re-post of a link that hopefully works )

www.oldengine.org/members/diesel/magnetos/Petrolmag.htm

Thankyou Eddie, that is a good start, I thought I'd seen a list that covered all the early Cats too, obviously you don't have it, I thought it might have come from your stash.
All the best
Mike

This is a little off topic but along the same line. At least in our area the folks that understand a mag are few and far between let alone someone that can rewind the exciter coil.
Has anyone ever modified a dead mag to basically use it as the timing device for a CD ignition? I know that is not the "purist" way to make an ignition for a pony nor does it help those that still use a lariat to start the pony as the CD requires a battery. The CD ignitions were simple and with a 2 cylinder and only about 3600 RPM should provide a hot spark.
Just wonder what we can do in the future as Mag parts become harder to find and the alternative to convert to direct electric is a parts nightmare to find them.
I've been cooped up too long because of this virus thing!!

Thankyou Eddie, those extra links are what I needed though I couldn't get the last one to work. Have printed to paper the great info.
Many thanks
Mike

I have a Wico XH-184, on my 22. Old Croak went thru it recently and it works great but to adjust the points you need to use a mirror since the points are forward facing, under the cap. I have seen the Eiseman photos and the points are reached from the top which I think would be much, much easier to adjust. Old Croak mentioned several mags that can replace the Eiseman and work fine. The Bob LaVoie book shows Eiseman GV4 and CT4 covering almost all gas Cats except the Thirty PS and the Cat 60 which used a Bosch ZR4. I dont remember what is on my Big 20, but it is some other brand that must have worked for years, since it has a layer of dirt on it. Just a little more info. Grant.

I assume there are many mags that could be fitted to an old Cat, the CT-4 and CM-4 used on the 22 are easy to work on for sure.

"D4Jim" wrote:

This is a little off topic but along the same line. At least in our area the folks that understand a mag are few and far between let alone someone that can rewind the exciter coil.
Has anyone ever modified a dead mag to basically use it as the timing device for a CD ignition? I know that is not the "purist" way to make an ignition for a pony nor does it help those that still use a lariat to start the pony as the CD requires a battery. The CD ignitions were simple and with a 2 cylinder and only about 3600 RPM should provide a hot spark.
Just wonder what we can do in the future as Mag parts become harder to find and the alternative to convert to direct electric is a parts nightmare to find them.
I've been cooped up too long because of this virus thing!!

I have seen mag's modified to use a external coil and a battery for power. Essentially just using the mag as a timing device as you suggest .
I will have a look and see if I can find a photo.

"Andrew" wrote:

I have seen mag's modified to use a external coil and a battery for power. Essentially just using the mag as a timing device as you suggest .
I will have a look and see if I can find a photo.

Morning Andrew, my first antique Cat, "Gwyns" 2 Ton had that set up, you had a 12 volt car battery resting between your feet as you drove the old girl, and it ran a regular car coil to produce the sparks.

I'm no magneto expert but I wonder how hard would it be to strip the armature of it's windings leaving just a bare drive shaft to the points and rotating distributor plate, then mount some high quality rechargeable batteries into the now empty magneto housing to set one up to run a CDI type ignition? For a show tractor the battery should have more than enough life I'd assume.

I'm not very bright as you know, so I'll probably stick to the entertainment, and pain factor of trying to get the original maggy to fire the old girls up each time, I mean what fun is there in seeing a old Cat fire up on the first compression stroke!!!
All the best
Mike

That last link works now Eddie, thankyou. Eddie, will a RT-4 or GS-4 magneto work in a old Cat, I've never seen them used or talked about for some reason, it is mostly G4 Editions 2 or 3 or CM-4, CT-4, RC-2Q and RC-2H, plus the Bosch MJK I see.
Thanks
Mike