JD420 ignition circuit

[kinghd]

Hi, new to TBN. Just bought an 88 JD 420 for $600. It won't start, no spark. checked everything down to the ignition control module. I'm getting full battery voltage on the negative post on the coil with no fluctuation. I know it's supposed to go down to 1 - 1.5 volts. My question is, how far do you need to rotate the flywheel to get that reading? Never worked on one of these before. Thanks

 

[Kish318420]

At least one full rotation, make sure you have removed spark plugs from cylinder and grounded them to the engine to complete the circuit. Also make sure gas is off!! Is this the P220G or the B43 Onan? If the B43 that will be a points ignition versus an electronic ignition which the P220G has.

 

[Rebeldad1]

Hi, new to TBN. Just bought an 88 JD 420 for $600. It won't start, no spark. checked everything down to the ignition control module. I'm getting full battery voltage on the negative post on the coil with no fluctuation. I know it's supposed to go down to 1 - 1.5 volts. My question is, how far do you need to rotate the flywheel to get that reading? Never worked on one of these before. Thanks

Maybe this will help
https://www.tractorbynet.com/forums/john-deere-lawn-garden/411226-jd-420-cranks-wont-start.html

 

[kinghd]

Ok, did more than one revolution and everything else but no change. Guess it's time to [ull the engine. Oh well, needed verification. Thanks.

 

[kinghd]

Thanks Rebeldad1. It turns over just fine, just no spark.

 

[Richard001]

At least one full rotation, make sure you have removed spark plugs from cylinder and grounded them to the engine to complete the circuit. Also make sure gas is off!! Is this the P220G or the B43 Onan? If the B43 that will be a points ignition versus an electronic ignition which the P220G has.

kinghd - you never answered Kish's question about which engine you have.

 

[kinghd]

It's an Onan P220G. Sorry, I didn't see this post.

 

[Kish318420]

I've posted the info on testing the P 218G/P220G Electronic Ignition Module for the 316/318/420

 

[kinghd]

Sorry guys, my laptop went down and had to get a new one. Kish, I appreciate the thumbnails. I have the whole 440 page shop manual and I checked everything down to the module on the flywheel. When I turn the engine the voltage on the negative side of the coils stays at 12 volts so I'm assuming it or the ring is bad. I'm going to pull the engine and find out. I only paid $600 for the tractor and it ran when I got it. Guess I'm going to learn a lot with this one.