Wico A series magneto

[JerryCPP(WA)]

I'm working on a Novo AG engine with an A series Wico magneto. The mag works, but is very stiff. A magneto repair shop says I need to remove the armature and check the shaft and bearings. I've never torn into one of these, and am not sure which end to start on. Remove the staked nut on the impulse and remove it? Take the screw out of the eccentric on the points? Any suggestions would be most appreciated.

 

[Steve@Advance]

This should help.

I'm sure there is more out there for the picking.
Wico A

 

[Dean]

I once had an AC WC with FM magneto that became difficult to crank start after the impulse stopped working.

Upon inspection, I found that heat had caused tar in the winding to flow onto the armature making it difficult to turn. The shaft would turn the armature and the impulse would wind up but the spring was not strong to spin the armature upon release. Result: Engine runs and starts OK with starter but difficult to start with hand crank. There was also no clicking of the impulse upon cranking or shut down.

The tractor had been sitting in the barn for years in a position where sunlight passed through a window and shined onto the magneto.

A couple of hours cleaning out the tar with gasoline, etc., solved the problem.

Dean

 

[JOCCO]

General thought is wico A was not the best mag in town.

 

[jeffcat]

Yes wico mags are supported with one "bearing" only. They work but....my Gravely has a Fairbanks. That end cap repro can cost ya $73.oo. Old gunked grease can be a joy.

 

[teddy52food]

Lots of parts in that impulse. Don't get them mixed up.