(quoted from post at 23:46:40 07/23/15) I got one of these fancy Pertronix ignitions for my positive ground 6 volt front mount 8N as well.. because I don't use my tractor much and I didn't like having to troubleshoot then polish up my points every season when I wanted to start up.
Installed all new wire harness at the same time, too. Started it up and it ran...for 15 seconds then died. :?
That was 4 years ago, and other projects and priorities have left it neglected.
Finally getting back to it. Just got done troubleshooting and checking out distributor and ignition circuit (which brings up a couple questions I hope can get help with, as well as my observations).
Yesterday reinstalled distributor and corrected a fault (described below) in my wiring. Though I didn't get engine to start, the ignition part seems to be working. Timing appears correct. A spark (evidenced by a timing light) is running down each wire.
Fault: I did not have proper resistance coming to the coil from the positive ground. Pertronix specifies a minimum of 1.5 ohms on the primary side (though it was not mentioned in the 1247P6 instructions I received with the electronic ignition, I learned this in discussion with their tech support-who are quite helpful). In testing my coil, I had 1.1 ohms on the primary, and 18,900 ohms* on secondary.
To bring this to >1.5 ohms, I sought out a .5 or so balance resistor. Found one on the tractor (the Resistor Assembly P/N 12250) which I had on the 'wrong' side of the ignition circuit... With the standard ignition, the ignition switch goes to the assembly, which then goes to the terminal at the top of the coil. (See diag. FO71)
http://img17.photobucket.com/albums/v51/drwhite/8N_wireing_1947-mid_1950.jpg
(I had a new one installed here with my new wiring that was .4 ohm. The original (in my parts box) is 1 ohm.) SO, that .4 ohm resistor is now in circuit between positive ground and the positive ground terminal of the coil (the exposed one at the top). The black wire that comes out of the distributor body from the Pertronix ignition now goes to direct to the ignition switch.
[b:909422b9dd]*Question: What should the values be on a good 6v front mount coil?[/b:909422b9dd] I am not sure this is a good coil. I was getting spark down the wires when cranking, but was not getting fire. Is their -enough- spark? (more testing later today).
Cleaned carb and reinstalled just before trying, and new gas, etc. Didn't check to see if plugs were getting wet/fuel actually making it all the way to the cylinders as dinner time arrived, but again, more testing to do today. Plugs were inspected/cleaned beforehand.
Main point here is to be sure you have a minimum of 1.5 ohms on the primary side of coil. I got that wrong on initial wiring and is possible it caused coil to fail when originally started it and it ran for the 15 or so seconds back when...
But a spark is still coming down wires per timing light...
Thoughts/Ideas?
Separate issue - once pushed started button, starter would not stop (had to disconnect battery). Disconnected starter button and still ran so figure the starter solenoid/relay has failed/stuck in the on (closed) position. Any good way to bench test this? When trying with just a light in the circuit, couldn't get it to close. Don't know if needs more amps pulling on it to work?
