A couple of years ago, I bought an old Jetstar 3 that was customized by Parsons with a 510 backhoe. It was in rough shape when I bought it.. and still is.
The tractor had been sitting outside for a couple of years before I bought it. To make it drivable I had a lot to do.
Finally, I got to the electrical. I had to swap the coil and resistor (inside of the distributor) After messing with the firing order, it started up and I drove it 10 miles home. It ran ok for a while. Then, last year I went out to start it... It had no spark. So I tested the coil. It seemed to be just a bit out of range so I replaced both the coil and resistor again.. No luck.. Still had no spark.. I let it sit through the summer.. and fall... Now, I have to move this to my new place so I can start restoring it.. So, Last week, I tested and found fluctuating 12v while jiggling the ignition and 0v going to my coil while cranking. The engine cranks as normal. So, I replaced my Keyed ignition and push button starter with new from amazon. Everything bolted in place the same way. I cranked the engine... Still had no spark. I tested the voltage at a solid 12.5volts whith the key on engine off. I tested power to the coil wire @ 4volts while cranking.. An improvement, but not enough to power the coil. I am using my power probe 3. The voltage is very erratic between 2-4 volts while cranking.
I tested on all 3 sides of the switch and push button. All read the same drop. I can trace the drop all the way back to the + battery terminal/ post While cranking.
I tested the starter with my low dollar ampmeter and it seems to readout 145 on the A~1000 setting or 14.5 on the A~200 setting. I have heard that anyhting over 250amps would be cause for concern (by pulling too much voltage? and not leaving enough for the coil/dist.? ) anyways.. I replaced the battery terminals and soldered them in. I checked the battery with my high dollar tester and even replaced the battery with another just to rule that problem out...
The starter may still be a problem. I have not tested any further. The starter solenoid seems to be the power distribution point. There are no fuses in the system.
Checked to insure that the wire going to the coil is connected to the ignition post on the switch.
Checked all connections. There is not too much corrosion. I cleaned the Battery terminals and posts.
I'm prepared to replace all of the wiring. As well as put in an electronic ignition.
Something tells me to keep looking into the starter. Maybe it is grounding or having another resistance issue that is creating and pushing back into the battery?
Although it cranks the engine just fine, I did over crank the starter last year. That may have stressed the starter a bit. but it ran just fine after that.
I'll pull the starter and take it in to the parts house and have them test it.
Also think it could be a defective switch, although, I tested voltage drop all the way back to the +terminal/ post. If it was a defective switch, wouldn't one side be read 12v and the other drop?
Its pouring down rain right now. So, I thought that I would write this with the hope to get some other ideas, before I go back out and work on it..
Thanks for reading this.
The tractor had been sitting outside for a couple of years before I bought it. To make it drivable I had a lot to do.
Finally, I got to the electrical. I had to swap the coil and resistor (inside of the distributor) After messing with the firing order, it started up and I drove it 10 miles home. It ran ok for a while. Then, last year I went out to start it... It had no spark. So I tested the coil. It seemed to be just a bit out of range so I replaced both the coil and resistor again.. No luck.. Still had no spark.. I let it sit through the summer.. and fall... Now, I have to move this to my new place so I can start restoring it.. So, Last week, I tested and found fluctuating 12v while jiggling the ignition and 0v going to my coil while cranking. The engine cranks as normal. So, I replaced my Keyed ignition and push button starter with new from amazon. Everything bolted in place the same way. I cranked the engine... Still had no spark. I tested the voltage at a solid 12.5volts whith the key on engine off. I tested power to the coil wire @ 4volts while cranking.. An improvement, but not enough to power the coil. I am using my power probe 3. The voltage is very erratic between 2-4 volts while cranking.
I tested on all 3 sides of the switch and push button. All read the same drop. I can trace the drop all the way back to the + battery terminal/ post While cranking.
I tested the starter with my low dollar ampmeter and it seems to readout 145 on the A~1000 setting or 14.5 on the A~200 setting. I have heard that anyhting over 250amps would be cause for concern (by pulling too much voltage? and not leaving enough for the coil/dist.? ) anyways.. I replaced the battery terminals and soldered them in. I checked the battery with my high dollar tester and even replaced the battery with another just to rule that problem out...
The starter may still be a problem. I have not tested any further. The starter solenoid seems to be the power distribution point. There are no fuses in the system.
Checked to insure that the wire going to the coil is connected to the ignition post on the switch.
Checked all connections. There is not too much corrosion. I cleaned the Battery terminals and posts.
I'm prepared to replace all of the wiring. As well as put in an electronic ignition.
Something tells me to keep looking into the starter. Maybe it is grounding or having another resistance issue that is creating and pushing back into the battery?
Although it cranks the engine just fine, I did over crank the starter last year. That may have stressed the starter a bit. but it ran just fine after that.
I'll pull the starter and take it in to the parts house and have them test it.
Also think it could be a defective switch, although, I tested voltage drop all the way back to the +terminal/ post. If it was a defective switch, wouldn't one side be read 12v and the other drop?
Its pouring down rain right now. So, I thought that I would write this with the hope to get some other ideas, before I go back out and work on it..
Thanks for reading this.