JD 70 Diesel Pony Motor Question

Farmeroza

New User
Howdy folks. Love these forums have gotten lots of info out from archives. But this one I cant find. I just got a JD 70 Diesel with the pony cranking engine. I replaced the coils and wires as I found them, but I don't know if they had been messed with before. I am trying to find how to tell what the cylinder numbers are. I know the firing order is 1-2-3-4, but which cylinder is no 1,2 3, and 4. Also the coils were connected sort of crosswise with the left coil connected to the right condenser / points and vice-versa, is this correct? ALso since both cables fire at the same time on one side, does it matter which cable goes to which piston on that one side? Thanks again yall!
 
As you're facing the coils, the lead on the left coil with the closed connecter goes to the left condenser/points terminal and the lead with the crow foot terminal goes to the post on the left side of the coil box. The right coil's leads are the same...closed connecter lead to right points/condenser terminal and crow foot terminal lead to post on the left side of coil box (coupled with crow foot terminal from left coil). Set points at 0.20 opening. The two plug wires from each coil go to the plugs on the same side as the coil. Short wire to front plug, long wire to rear plug. To check if you have spark on each side, remove the plug wire from the front plug and hook it to a spare plug that is grounded to the engine. Should see a bright blue spark when the ignition is on and the pony engine is cranked. Do the same procedure for both sides. Both plugs must be grounded for the coil to work. Make sure you have the correct plug wires for the coils you have. JD coils/wires are different than the cheaper foreign coils/wires.
 
Thanks blksmok! They didn't look right to me crossed like they were. Do you by chance know how the cylinders are numbered as you face the coils?
 
Without looking in the service manual...I consider #1 and #3 cylinder are on the right side and #2 and #4 on the left side. Since the coils fire two plugs at once it doesn't matter unless you got the left coil hooked to the right spark plugs or the right coil hooked to the left spark plugs.
 

Welcome to YTmag.
A single coil fires two plugs simultaneously.
Autolite 317 non resistor plugs are recommended.
The ignition wires and coils have to match. There is a "spike post" ignition wire and coil set. And a "spring clip" coil and ignition wire set. Mix them up and spark will be poor to nil.
Don't forget and leave the ignition switch powering the starting engine coils , without the starting engine operating. The coils will smell like burning money.
 
Thanks for the help. Darn it @$$@@##@@! The kit I bought, I think had what you mentioned. The cables had metal cones on the end and the coils had metal spike in the middle. I figured I'd cut the cones and insert it onto the spike. I guess it ain't gonna work is what your sayin.
 

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