Found the trouble -mag cap

Super-H-Mike · Sep 8, 2011

On my 27 Regular that stalled the other day, I took off the Mag cap and can see the brush that points down is gone. I presume this is to pick up the spark from the coil. What do I need ? Brushes or a whole new cap ? And where to get it. E4A Magneto. Thanks ~ Mike

James Williams · Sep 8, 2011

Mike,protect that cap as far as I know there not available,Rice equ has every thing else

jimmy

Tom Fleming · Sep 8, 2011

It takes a standard E4A brush, and yes Rice Equipment has them, as well as any good magneto shop. It is a simple install. Depending upon the condition of the rest of the brushes, you might consider replacing all of them. The last ones I bought were about $3 each.

Anonymous-0 · Sep 8, 2011

Hmmm... I didn t see them in their catalog, got a part number by chance? I didn t see much E4A stuff there at all, or at Fordson, it was all F4. Also, correct me if I m wrong, but I should be able to test for spark right off of that commutator or ring that my lost brush rode on ? Every time the impulse trips I should pick up a spark off of there right

Oldiron29 · Sep 8, 2011

Mike, I get my Mag parts from John Brillman
toll free 888-274-5562 he has all wiring and electrical parts. oldiron29

rhtx55 · Sep 8, 2011

Glad it was something rather simple.

Tom Fleming · Sep 8, 2011

Mike, Oldiron gave a good source. You will have to call Gordon tomorrow. Not everything he has is in his parts list.

Super-H-Mike · Sep 8, 2011

Thanks!I will try that source in the morning. Any thoughts on my theory about checking for spark off the ring?

Nebraska Kirk · Sep 8, 2011

That carbon brush is the same as those used in the F4 cap. You could even use the brush out of the center of an H4 magneto distributor cap, or even a battery ignition distributor cap, all the carbon brushes will interchange. As far as checking for spark with the cap off, you can spin the mag over by hand and you should see the spark jump the safety gap from the ring to that pointed ground screw in the side of the magneto. You can also take a short length of copper wire and let one bare end touch the collector ring and hold the other end 1/4" away from the side of the mag to check for spark. Or even take one of the 4 carbon brushes out of the cap that go to the spark plug ports and put it in where you lost one, you can then check for spark at 3 of the 4 plug wire terminals.

Those carbon brushes have a tapered coil spring behind them to keep them in firm contact. Twist them clockwise while pulling out, they will come out easier this way and you won't stretch the spring either. Twist clockwise when installing as well.

Super-H-Mike · Sep 9, 2011

Thank you Neb. Kirk, I am gonna follow that advice ! The safety gap, is that so when the unit is off the tractor and someone spins it, it doesn t zap em ? Much apreciated ~ Mike

Super-H-Mike · Sep 9, 2011

Ok, I may have spoke to soon, and my problems are deeper. It must have been running with that brush gone for awhile, just jumping to the spring. By using the wire off contact ring and impulse set to on, cranking, I have very weak and incosistant spark. So, next file points and check magnet? I am gonna try attaching pics to this reply.

Super-H-Mike · Sep 9, 2011

More pic

Nebraska Kirk · Sep 9, 2011

(quoted from post at 09:27:46 09/09/11) Thank you Neb. Kirk, I am gonna follow that advice ! The safety gap, is that so when the unit is off the tractor and someone spins it, it doesn t zap em ? Much apreciated ~ Mike

The safety gap is to protect the magneto coil, not you! If you are spinning the magneto without a way for the electricity to get back via a ground, either through spark plugs or the safety gap, then that high voltage electricity has the potential to short out through the coil windings and then the coil is fried.

Tom Fleming · Sep 9, 2011

I agree with Kirk about using F4 brushes, they will work fine. I have an E4A that I just cleaned up and put new points in. I had it in the vice, and put wires in that I have in a harness to check mags. All 4 wires have a plug at the end of them and they are are grounded to the mag. I can get a good blue spark spinning the mag by hand in this setup. I would get the brush in the cap and re-assembled to do my testing if I were you. There is not a good way to get clean, consistent continuity using the wire as shown in your pictures. The wire works, but it needs to be going to a clean bare metal surface. It is even better going to the mag frame. IMHO.

Super-H-Mike · Sep 10, 2011

Thanks Tom. Actually this wire set up works pretty good, I filed and gapped my points and now I get a sharp blue spark at every turn of the crank. I ordered all new brushes from Fordson House, and I believe I will back to running after they are in. Then I will take carb apart and clean it again, and put in brass float.

Found the trouble -mag cap

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