8n spark

8n with side mount distributor. It has an aftermarket starter button and on/off switch. I have been using this tractor for 7 years without issue. It is still 6 volt. Been fighting this since last fall. It quit running, determined there was no spark. Chasing it down testing everything, found the coil wire grommet to the distributor was broken. Fixed that, ran fine. Also replaced the copper strip and insulator, condenser, points (gapped to .025), cap, rotor, and plugs. Went to start it this spring, wouldn"t start, no spark. Tested evrything out, found nothing. Recharged battery, it started and ran for 10 minutes then died and wouldnt start again. Retraced my steps, made sure nothing (copper strip, etc.) was grounding out. Pulled a plug to check again for spark, turned engine over and it started. Shut off engine, reinstall plug, wont start. Pull plug again (what the heck, right??) and no start, no spark. Tested switch, it was fine but replaced it anyway, tested coil, it was fine but replaced it anyway. Replaced plug wires. Have rechecked all connections at least twice. Cleaned up plugs and points, tractor started and quit within 10 seconds. Cleaned plugs and points again, no start. SO, to sum it all up,...new points, plugs, condenser, cap, rotor, plug wires, coil, switch, copper strip and insulators. I am stumped. Any suggestions are appreciated.

well.. you got it to start and run 10m.. so you know it WILL run.. and is at least itmed close enough to start.

jump power right from battery to coil.

see if ya got spark.

while a start and run for a short time is usually making me think fuel... however. you report no spark.. so we need to correct that first.

post back after the hot wire test.

if nothing on hotwire. insuert a test lamp in line and turn key on. lamp should blink as you crank.

lamp on 100% time = a short past the coil.

lamp never on = an open circuit somewhere.

I have power to the disty (is that what you were looking for per your test?). Here is more info. I have 6.2 volts at the coil, both + and - sides with switch on. I have 6.2 volts at coil wire going to disty with switch on. I have 6.2 volts at wire going to points with switch on, 0 with switch off. With switch on, I have 6.2 volts at dist body with points closed, 0 with points open. I read on a message to take main coil wire and hold it to ground while opening and closing points I should get a spark at coil wire. What I got was spark at one of the screws that hold the cover down underneath the points. I also get good spark when I short the screwdriver from the points to the distributor shaft (wasnt on purpose, but good spark none the less).

(quoted from post at 20:18:21 05/13/13) I have power to the disty (is that what you were looking for per your test?). Here is more info. I have 6.2 volts at the coil, both + and - sides with switch on. I have 6.2 volts at coil wire going to disty with switch on. I have 6.2 volts at wire going to points with switch on, 0 with switch off. With switch on, I have 6.2 volts at dist body with points closed, 0 with points open. I read on a message to take main coil wire and hold it to ground while opening and closing points I should get a spark at coil wire. What I got was spark at one of the screws that hold the cover down underneath the points. I also get good spark when I short the screwdriver from the points to the distributor shaft (wasnt on purpose, but good spark none the less).

Click to expand...

screws attach breaker plate to distributor body. It sounds like corrosion has gotten in & isolated the plate from ground. I have seen this before. Clean up plate to body interface & put star washers under those 2 screws...possibly just the washers will do the trick for you.

ditto what jmor said. it may be the points are not grounding when closed because breaker plate is partially inuslated by corrosion / not properly grounded

Tried just cleaning up where the screws attached and underneath the star washers, no luck. Took out the breaker plate and took some emery to it, as well as the lip that it sits on and .........vroom vroom! Thanks for the help!

You are more than welcome! I chased that one before, out in near 100F Texas sun, so happy to save you that!