Weak spark and hard to start

[asphelt]

1949 (?) 8N Front Distributor, 6V is hard to start when cold and impossible to start when it's warmed up.
I've read on this forum, fuel, air, spark. When I checked the spark I used a spare spark plug (.025) and no spark... but (there's always a but) I was getting a shock holding the wire. Not a "knock you in the dirt" shock, but I could feel something was happening. I reset the gap to .015 and still no spark across the gap, but in my hands.

With coil removed the resistnace is ~4 ohms. Coil installed the resistance is in the meg-ohm range?

Where's my sparky-mister when I need him?

 

[Dell (WA)]

asphelt........uh? you do know ittza 2-bolt, 15-min job to remove the weird 4-nipple front mount dizzy and adjust the points (0.015") on the kitchen table, don't you??? Just un-snapple yer capple and letter dangle. Installation is a reversal of the removal ...except... finger start the 2-bolts and install the rotor. Now gently twist the rotor so the OFF-SET drive tang fits into the camshaft OFF-SET drive slot. Tighen yer 2-bolts and re-snapple yer capple. Simple, eh?

Remember to "polish" the invisible corrosion from between the points after installation. I use a clean $1-bill and pull. Iff'n yer really cheap, tear a strip from HEAVY brown paper grocery sack and use that.

As fer resistances, from the top terminal to the springy thingy is about 1-ohm. From the top terminal to the blade is about 6000-ohms. You should also read about 6000 ohms between the coil thingy to the blade.

As fer checking yer sparkies, I recommend enny o'sparkie by bending the side electrode out fer a full 3/16-gap. Now clamp the metal hex to enny convient bracket and with tranny in NEUTRAL, ignition switch ON, crank yer starter motor while watching fer HOT blue sparkies jumpin' the 3/16" (0.1875") gap. Iff'n the sparkies are orangish-yellowish, guess what??? Probably yer points need replacing.

Iff'n replacing yer points don't fix yer weak sparkies, then time to replace yer weaksister ignition switch.

As fer the "tingle" while holding yer sparkie wire, guess what??? Sparkie wire insulation don't last forever. Recommend NEW cut-to-fit COPPER-CORE sparkie wire. .......HTH, Dell, yer self-appointed sparkie-meister

 

[asphelt]

Dell:
Thanks. I'll re-check the coil resistance.
Plug wires are new yesterday (discovered #1 was broken.)
Points were checked yesterday (.015).
Plug wires were installed to the right ports on the dizzy cap.

I also swapped the coil from a good starting '48 8N, 12V, assuming the coil would be the same since there were two resistors on the '48. Still no start.

 

[old]

With the cap off but the coil on and ignition on open and close the points by hand. You should both see and hear a spark there and if your not careful feel a spark. Sounds like your points are dirty or corroded and that will cause weak or no spark

 

[asphelt]

Thanks for the help. It now starts on the 2nd rrumpah and is hitting on all 4! I took it to the field and mowed for about an hour and everything seems fine.

Turns out, I had 2 problems.
1. The coil was bad. The first indication was the low resistance measurement, the 2nd was the varnish that had escaped and was evident at the base of the springy thing.

2. The new coil I purchased was bad. This drove me crazy. Even the new coil wouldn't consistently jump a spark on the test plug. I once again took the coil from my '47 and tried it again. (That tractor starts good) Woo-Hoo we've got good spark.

Looking at the two coils, I determined the secondary tab (on the new coil) was not long enough to reach the contact point on the cap.

After installing the distributor about 3 times, I made a tool, installed jumper wires where needed and turned the distributor with a drill. We knew we had it fixed when a spark jumped from the empty #2 distributor cap hole to my helpers finger. He immediately told me it was working.

3. Carb was flooding. After fooliing with it several hours, I discovered some PO had bent (rotated) the left float lung and it was evidently hanging, either too low (ran out of gas) or too high (gas ran out the air intake port). Per advice on other posts, I set the jet(s) at the initial setting per the FO4 and left them alone.

All is well. Thanks for your help on this post and others.

Ron

 

[Greg Baisch]

So it appears that you know a few things about the ol 8n. I have a 49 with a side-mount distributor. I have just put a 12V kit on it (resistor, coil, alternator, wiring harness, plugs and wires). I have 12.6V at the coil, but no spark.

Point and condenser are new....just replaced. And now i am officially stumped.

Resistance at the coil is 3.1 Ohms
Resistance at the new resistor from the kit is 3.4 Ohms.

Any ideas?

 

[Britcheflee]

Is there a great deal of differnce between the copper cored spark plug leads and what is a regular metal spark plug lead? Would this cause a misfire if one lead was of that different material?


Lee

 

[1951 8N]

So it appears that you know a few things about the ol 8n. I have a 49 with a side-mount distributor. I have just put a 12V kit on it (resistor, coil, alternator, wiring harness, plugs and wires). I have 12.6V at the coil, but no spark.

Point and condenser are new....just replaced. And now i am officially stumped.

Resistance at the coil is 3.1 Ohms
Resistance at the new resistor from the kit is 3.4 Ohms.

Any ideas?

You don't have a 1949 8N if it has a side mount distributor. It has to be a Mid 1950, 1951 or 1952 8N to have a side mount distributor. I hope this info helps.