John Deere 420w

[Freddie2010]

Hi, I called to order an electronic ignition for my John deere 420w . I was told that I would also need a hot coil and graphite spark plug wires. The coil alone was another 60 dollars I don't know how much the plug wires are. Are the coil and spark plug wires absolutely nessary when I install the electronic ignition. ? thank you very much for the help. Fred

PS. I just installed a good coil from NAPA auto parts, with internal resistance when I changed it over from 6 volts positive ground to 12 volts negative ground.

 

[M-MAN]

Yes you need graphite wires. No you don't
need a hot coil. You will need to check the ohms on your coil to see whether you need a ballast resistor or not.

 

[Freddie2010]

(quoted from post at 16:20:24 12/25/23) Yes you need graphite wires. No you don't
need a hot coil. You will need to check the ohms on your coil to see whether you need a ballast resistor or not.

Ok. How do I check the ohms and what should it read? thanks

 

[M-MAN]

Your new coil labeled no external
resistor needed should be correct but you
still need to be positive the ohms match
the instructions. Just set your meter to
ohms and put the leads on the two small
coil posts. A 12v coil requiring a
resistor will read approximately 1.5 ohms
and one that doesn't should read
approximately 3 ohms. The instructions
will tell you what you need.

 

[Rusty wheel]

Just curious, why electronic ign? Are you gonna pull it?

 

[Freddie2010]

(quoted from post at 09:00:22 12/26/23) Just curious, why electronic ign? Are you gonna pull it?

No, I am not going to pull it. I let it set for about two months. When I tried to start it. It would not start until I cleaned the points. I thought if I put an electronic ignition on it, I would not have that problem.
Is it not a good Idea to put an electronic ignition on it ?

 

[buickanddeere]

A plain boring 6V napa coil is plenty .
Graphite resistor ignition wires eventually fail. The wire wound suppression wires are durable .