john deere d wico magneto

[Mike Privett]

Can anyone help me on how to time a wico x magneto on a 1928 john deere D

[Dempster]

I'll paste in my version of it I supply with mags when they go back. The JD manual that D would be DIR-108 still available from JD publications 1-800-522-7448. http://techpubs.deere.com/

Magneto Timing D early unstyled 24-30 :

Timing mag for D #30400-109943:
1. Have the mag secure to engine mounting and need 1/32" clearance between mag drive and float coupling.
2. Loosen the 2 clamps on mag engine drive flange allowing mag to turn freely.
3. Remove LH spark plug # 1 cylinder flywheel side. Turn engine forward in direction it runs to compression stroke on LH cylinder (flywheel side) with mark on flywheel "L.H. Ret. Spk." in line with the arrow or mark on cover at 3 o’clock position.
4. Remove breaker cover and dist. cap on mag.
5. Set spark lever clear back (fully retarded spark).
6. Turn magneto same direction as flywheel runs until brass segment on distributor disc is in upper right hand corner and breaker points are just beginning to open.
7. Tighten 2 bolts on mag drive flange.
8. Spark plug wire from forward mag terminal goes to LH spark plug and rear one to RH spark plug.
9. Then check the impulse trip by turning flywheel back 1/2 turn and if mag has manual impulse trip you will have to set it to trip. Then rotate engine slowly forward and impulse should trip or click as mark on flywheel lines up with mark on cover at 3 o’clock position and LH spark plug should fire. If not loosen drive flange bolts and if trip is early turn magneto opposite direction engine runs. If late turn mag same direction as engine runs and recheck until you get mark to line up.
If that doesn't get you in time then you could have mag impulse problems or need to time the camshaft properly. Good luck.