720 diesel help

[Cowman74]

We are working on our 720 diesel. We had the pony motor off 10+ yrs ago and when we replaced it we didn't hook up the wires to the starter and the mag. We have been parking it on a hill for years because the pony motor didn't run right. I want to get it going again cause that is a pain in the butt now that we don't use it all the time. So here is my question:
Where do the wires go off of the starting button? There seem to be 2 coming off of there. Do they both go to the starter? if so where? or does one go to the mag? if not which wire goes to the mag? Also is this tractor positive or negative ground? I know all other 2 cylinders are. Any help would be great.

 

[Jake Winn]

i would highly suggest a 720 tech manual or if not that, a Two Cylinder electrical service manual. Either can be found on eBay pretty easy. It makes it a lot easier to get it right.

 

[730d se]

Go to www.jdparts.com
Sign in or register if never been on.

Go down the left side to "Start Search Here" for manuals. Type in "720". Click on "720 diesel". It will bring up the whole parts manual that has the wiring diagram in it.

 

[F-I-T]

>>...There seem to be 2 coming off of there. Do they both go to the starter?>>>

See diagram. One line to the pony distributor supplies pure, un-modified battery voltage to the pony ifnition system while cranking when voltage typically drops, and the other runs the distributor supply voltage throughh a droppong resistor to save the coils during normal running time.

>>>...or does one go to the mag?>>>

It's a distributor, get things right before you find you've burned the coils out.

>>>...Also is this tractor positive or negative ground?>>>

Yes, as original, it would have been positive ground.

720D GES wiring

 

[Anonymous-0]

Thanks you I did find this in the parts book last night while playing online. Thansk you for your help.

 

[730d se]

The starter switch is a two way switch in a sense.
When starting (depressing the switch), it sends full battery power to the starter solenoid and coils as it bypasses the resistor going to coils. When the pony engine starts (releasing the starter switch), it adds the resistor back in the circuit to the coils so they only get about 1/2 of the battery power which is all they need.
The correct switch and the correct resistor must be in the circuit or it will get expensive in a hurry as your coils will not last long.
Please feel free to ask any of us if it is not clear.
Wired properly, good quality coils will last a long time.