John Deere B - Wico Model C

[Ted Neis]

I have a John Deere B 1942, Hand start with a WICO Model C Mag. The problem is with the rotor. It has a Copper Spring inside and a flat spot for the spring. The shaft on the Mag has a much larger flat side. I can force the rotor on the shaft but then it is loose and will turn on the shaft. What am I doing wrong? According to any information I can get it is supposed to be the correct rotor but if it is loose I can't see how it can hold a timing setting.
Ted Neis

 

[Duane Larson]

Ted,
If the copper spring inside the rotor button has the proper tension, and the flat spot on the magnetic rotor is not damaged, the rotor should center and not be easy to rotate when placed on the shaft. The bend in the copper spring gets flattened out with use and looses its tension, allowing the rotor to rotate when placed on the magnetic rotor shaft - and that is most likely the problem with your rotor.