magneto timing

[marvin gillson]

I am having trouble timing my 1939 JD A. Where is the timing mark on the case? There is a dimple on the cast iron frame behind the flywheel. Is this the timing mark? Thanks MG

 

[Arthur]

I might be wrong, but if its only a 2 cylinder, and its not firing right, i would think you would you would just swap the wires on the mag...Good luck

 

[James Howell]

Last Saturday I installed a magneto on 'Uncle Earl' my 1939 B.

The installation instructions that I used are located at the link below.

I removed the left spark plug and laid it against the frame to check the spark in relation to the LH Impulse.

It did not 'fire' on the LH Impulse so I removed the magneto and rotated the impulse counter clockwise 180 degrees and reinstalled.

It did 'fire' on the LH Impulse after making the adjustment.

The 'quick fix' is to just swap the spark plug wires.

Hope this helps.
Installing the Magneto on the Tractor