Hi: My name is michael and I am going insane due to working on this pony motor. insanity equals doing the same thing over and expecting different results. That being said my main problem with this 720 is I have no spark. Haven't had any spark and don't see a future of having any spark and this has to change.
Things I have done:
Changed coils, spark plugs, checked spark wires for continuity, checked capacitors and set points. All this over and over and...
I have been looking for the firing order and this morning I found it due to this forum, what i have not found is specifics for resistance on things. But as I have been reading through all the JD720 posts it has occurred to me that maybe my ohm meter is not working properly.
So is the first set of points and coil that attaches there to in the rotation of the cam lobe the coil that plugs into the first pistons as viewed from the gas tank? If so then the other coil is for the back plugs, right? If this is so then that I can correct but that does not help me with the spark.
K, I checked the capacitors and one will not hold a charge while the other one bleeds off very slowly. I always thought that a capacitor was supposed to dump its voltage. Anywhoo, I went and talked to an ag-west mechanic and he told me that the capacitors were actually a shock absorber for the voltage spike...K, that i can deal with but I still have no spark....?
I checked the spark and found that the voltage coming out was at 14V. I know this because I hooked up my Vmeter/ohm to one on the highvoltage setting at 500 and the numbers were 1428 and 13xx. The fact is the voltage stayed above 12xx. Also hooked up a light, Umm?, I don't know what it is called but it is one of those little lights that is in the middle of spark wires and attaches to the plug and the spark wire. The color of the light showed red, so I know the spark is going to ground. So I closed the point gaps and the spark gaps and achieved a little brighter red spark.
Also tried, courtesy of ag-west mechanic, energizing a coil and taking the point/capacitor feed wire and grounding to achieve a spark at the plug. Was not successful in this endeavor, what I mean is I did not get a spark at the plug.
K, I know the points are not grounding out or the coils along with the capacitors. The resistor carries continuity with a volt drop of .02 volts.
As you can see I have checked, rechecked and over checked the system and most likely am correct in the assumption that the multimeter has went gunny sack.
Any help? Or do I just get a big hammer and pound everything into submission?
Oh and another thing I have the chance to work on a lot of old tractors for this guy, and I mean Molines, Olivers, Masseys, Intersmashabels, Dutez and one water pump which is a W9 gas to diesel. The W9 is the next victim which will be most likely a total tear down, but I cannot progress until I get this 720 running along with 3 other tractors in which I am waiting for parts. Oh and there is a fine running 4020 that is for sale as soon as it gets painted.
Sorry to dump so much on any one who reads this but like i said this 720 has tested my limits and I just might have stepped over :arrow:
Any help will be very appreciated thank you!!!!!!
ps: Is this tractor a positive ground?
Things I have done:
Changed coils, spark plugs, checked spark wires for continuity, checked capacitors and set points. All this over and over and...
I have been looking for the firing order and this morning I found it due to this forum, what i have not found is specifics for resistance on things. But as I have been reading through all the JD720 posts it has occurred to me that maybe my ohm meter is not working properly.
So is the first set of points and coil that attaches there to in the rotation of the cam lobe the coil that plugs into the first pistons as viewed from the gas tank? If so then the other coil is for the back plugs, right? If this is so then that I can correct but that does not help me with the spark.
K, I checked the capacitors and one will not hold a charge while the other one bleeds off very slowly. I always thought that a capacitor was supposed to dump its voltage. Anywhoo, I went and talked to an ag-west mechanic and he told me that the capacitors were actually a shock absorber for the voltage spike...K, that i can deal with but I still have no spark....?
I checked the spark and found that the voltage coming out was at 14V. I know this because I hooked up my Vmeter/ohm to one on the highvoltage setting at 500 and the numbers were 1428 and 13xx. The fact is the voltage stayed above 12xx. Also hooked up a light, Umm?, I don't know what it is called but it is one of those little lights that is in the middle of spark wires and attaches to the plug and the spark wire. The color of the light showed red, so I know the spark is going to ground. So I closed the point gaps and the spark gaps and achieved a little brighter red spark.
Also tried, courtesy of ag-west mechanic, energizing a coil and taking the point/capacitor feed wire and grounding to achieve a spark at the plug. Was not successful in this endeavor, what I mean is I did not get a spark at the plug.
K, I know the points are not grounding out or the coils along with the capacitors. The resistor carries continuity with a volt drop of .02 volts.
As you can see I have checked, rechecked and over checked the system and most likely am correct in the assumption that the multimeter has went gunny sack.
Any help? Or do I just get a big hammer and pound everything into submission?
Oh and another thing I have the chance to work on a lot of old tractors for this guy, and I mean Molines, Olivers, Masseys, Intersmashabels, Dutez and one water pump which is a W9 gas to diesel. The W9 is the next victim which will be most likely a total tear down, but I cannot progress until I get this 720 running along with 3 other tractors in which I am waiting for parts. Oh and there is a fine running 4020 that is for sale as soon as it gets painted.
Sorry to dump so much on any one who reads this but like i said this 720 has tested my limits and I just might have stepped over :arrow:
Any help will be very appreciated thank you!!!!!!
ps: Is this tractor a positive ground?