dead early 8n

[Phil G]

Need some help! Got dads old early from dist 8n. No spark. I have done this..new points gapped as per man. rotor cap.condensor..I guess. No spark new 6V battery. I did not replace coil...supplier was out and ordered it. Is it more than likely the coil? Also what about the regulator.. replace it? Also there is a fairly heavy wire behind the dash that is I believe red and has a factory round connector...any ideas on this wire.. big thing...NO spark...Thanks Capt Philly in Northern Michiagn

 

[oldtanker]

First thing is stop throwing parts at it. Check to see if you have power through the switch with a test light or meter. Then check voltage to the coil and then to the points.

Rick

 

[oldtanker]

First thing is stop throwing parts at it. Check to see if you have power through the switch with a test light or meter. Then check voltage to the coil and then to the points.

Rick

 

[dont_know_a_thing]

I don't know... but the first thing I'd do is trace that "fairly heavy wire behind the dash that is I believe red" down and see where the other end is it.....

 

[Bruce (VA)]

There are two schools of thought when it comes to getting a non-running tractor to start. One way is to just start replacing every part you can get to until it starts or you run out of money. The other way is to take a step-by-step approach to solving the problem, working from most likely to least likely. The trick to fixing these tractors (or trouble shooting any piece of equipment) is to be systematic about it. You need to isolate the problem step by step and work from most likely to least likely. You have solved half the problem by determining it is a spark problem. That doesn’t mean you need to replace all of the electrical parts on the tractor!

Get you meter out. The ignition circuit goes from the battery to the solenoid then to the terminal block then to the switch then to the coil. Trace the circuit. When you get to the top of the coil, you should have 6v (points open; about 3v if closed)

Assuming that the bushings & advance weights are ok, & that you have correct voltage to the coil, the most common electrical failure (no spark, weak spark) points on the frontmount are:

1. The insulator under the brass concave head screw.

2. The insulator at the end of the points where the copper strip attaches.

3. The copper strip is broken or grounded to the plate.

4. The condenser wire grounding.

5. The pigtail/tab not making contact.

6. Incorrect positioning of the spring clip on the plate causing the pigtail to ground.

7. Incorrect seating of the coil on the distributor due to a loose bail or no gasket; the coil must not move at all.

8. Water/moisture inside the cap due to gasket failure or the absence of a gasket.

9. Dirty/corroded/incorrectly gapped points

10. Burned rotor, cracked/carbon tracked cap.

Unless the coil is cracked or shows a dead short, chances are it's fine; square coils rarely fail cold. Pull the distributor & do a continuity check.

First, make sure your meter/light works (don't ask....)

Next, dress the points by running a piece of card stock or brown paper bag through them. New points sometimes have an anti-corrosive dielectric coating on them & old points can corrode or pick up grease from a dirty feeler gauge or excessive cam lubricant. Then, check the gap at .015 on all 4 lobes.

Now, follow these steps:

1. Coil off, cap off, points open. One probe on the brass screw & the other on both sides of the open points. On the side closest to the cam, you should have continuity. Not on the other side! If you do, you will also have continuity everywhere because the points are grounded.

2. Coil off, cap off, points open. One probe on the brass screw & the other anywhere on the body of the distributor. You should have no continuity! Now, rotate the tang on the distributor....as the points open & close, you have continuity (closed) and lose it when they open.

3. Coil on, cap off, points open. One probe on the lead on the top of the coil, the other on the cam side of the open points. You should have continuity!

4. Coil on, cap off, points open. One probe on the lead on the top of the coil, the other anywhere on the body of the distributor. You should have no continuity!


At this point, I just put the distributor, coil & cap all back on the tractor as a unit (it’s easier to do this from the left side). The reason I do this is because it is real easy to get the cap or coil mis-aligned trying to put it back together one piece at a time & the result is something gets broken or you get a ‘no spark’ problem.

Post back w/ results & any other questions.
50 Tips

 

[Phil G]

Thanks guyz for the tips... you gave me aplace to start and the throwing parts at it thing before checkin...well I know better than that...I thought..Phil..gonna see where the juice ends first...hey just for grins this ole girl has really funky lookin wiring as in reall breakin down and freyed would a new harness be a good bet at some point...Thanks

 

[Bruce (VA)]

At some point? How about now. Check out tip # 42.
50 Tips