fm type j magnito

[johnz]

hi guys, i'm new here have been searching for info. on dissasembly of a type j mag. i'm trying to get the rotor out for cleaning as there appears to be rust covering the magnets and laminations, thinking i'll get a little hotter spark! any help or advise will be appreciated, thanks john o by the way i have the cover, points and front plate off.

[KidDynamo]

As I recall, you need to extract a retainer clip that holds in the gear-end bearing before you can readily remove the rotor. One time, I tried to bang a rotor out without removing the retainer clip (I didn't know it was there), figuring that I'd just shove the rotor out from the bearing race. It didn't work, I felt foolish, and the rotor shattered.

To gain accesss to the retainer clip, I think you need to remove the coil so that means you need to remove, or at least loosen, the screws that clamp down on the coil core to hold the coil in.

These screws thread down from the top. If you're lucky, somebody put a glob of a sealant over the screws to seal them. If not, they may just loosen up anyway, however, the dis-similar metals of the aluminum housing and the steel screws can sometimes make them hard to remove.

If you break the screwheads, though, they can be a real bug to drill out so don't let that happen. Use heating and cooling or whatever but dont break the screwheads or you'll likely need a new mag housing before you're done.

Once the coil is out and the bearing retainer clip is removed, you should be able to remove the rotor, but NOT SO FAST !

Have a pen and paper ready to make a note of all the little shims and so forth that you will have on the rotor end. These can differ a little and they are easy to get confused if these notes aren't made as you go along. You'll be happy to refer back when you reassemble!

That's how I remember doing the type J mag disassembly but then it's been a while. These are great magnetos, too !! Hope this helps.

[Francis]

John,
Here is a web site (Generated and maintained by Peter Forbes) that might help you.
< http://www.oldengine.org/members/die...s/MagData2.htm >
Another thing is the ball bearing is held in place (in the housing) with a paper shim.

[johnz]

thanks much guys, i was afraid i'd have to take the coil out. i've tried to remove the coil retaining screws - they will not budge however the screw heads are still in good shape as i have used good fitting screw drivers will keep trying i have lots of time thanks again this has helped a lot john

[KidDynamo]

Yeah, those screws need a drop of paint or goop to seal them from the elements and this is often not done. I have used a jewelers tip on oxy/acetylene to rapidly heat the screw heads without getting the entire housing hot. They will expand as they heat and maybe soften crud on the threads. Let everything cool down and then try again. Repeat.....

Patience is the key. I have encountered one half of a screwhead broken off and this makes it tough to drill out.

When you replace the screws, put a little anti-sieze on the threads and then a drop of paint or permatex on top when you're sure you're through.

[Jim D]

Hi, I`m having some trouble with the clip mentioned in this thread-- I pounded out my armature without removing the clip, now I`m trying to figure out how to put the mag back together. Can anyone decribe, or have a link to a diagram that shows how the clip goes back into the magneto