Exhaust popping, losing power when hot

[SPYDERLK]

Did you ever change out for a new distributor cap?

 

[jimjumper]

I currently have 3. The original, a new one, and one that came with the new distributor, points, rotor and condenser assembled set that I currently have installed. I also have the same supply of points, rotors, condensers, and coils. Only have 2 resistors though...

 

[EdGooding]

I've narrowed it down to a specific at least. I am getting a weak spark when it starts and then as it runs the spark gets weaker as the battery dies. I replaced the generator and VR already with a new generator and cutout but it doesn't appear that I am getting any output to the battery/coil. So, when I increase the RPM's or put it under load the cylinders start missing and it eventually dies. If I remove and charge the battery seperately it will run off the battery at full power for about 30 minutes and then slowly start missing again. I have 6V at the battery (not running) and the same voltage when it is running so I am assuming that the new generator/cutout isn't working and the coil, slowly, doesn't get enough voltage to keep it running. At best I get an orange spark on the spark checker that fades when applying more throttle. it also runs longer and better if I jumper the ballast resistor so I'll have the shop check the new generator/cutout. This has really gotten to be a long process...

When the 8N came out, Ford replaced the cutout relay with a voltage regulator. You may want to consider taking it back to factory spec.

 

[rScotty]

I've narrowed it down to a specific at least. I am getting a weak spark when it starts and then as it runs the spark gets weaker as the battery dies. I replaced the generator and VR already with a new generator and cutout but it doesn't appear that I am getting any output to the battery/coil. So, when I increase the RPM's or put it under load the cylinders start missing and it eventually dies. If I remove and charge the battery seperately it will run off the battery at full power for about 30 minutes and then slowly start missing again. I have 6V at the battery (not running) and the same voltage when it is running so I am assuming that the new generator/cutout isn't working and the coil, slowly, doesn't get enough voltage to keep it running. At best I get an orange spark on the spark checker that fades when applying more throttle. it also runs longer and better if I jumper the ballast resistor so I'll have the shop check the new generator/cutout. This has really gotten to be a long process...

Those symptoms - failing spark as it heats up - would normally lead to a bad condensor and/or coil - but you said you changed those. So I am out of ideas.

 

[SPYDERLK]

Did you ever change out for a new distributor cap?

I currently have 3. The original, a new one, and one that came with the new distributor, points, rotor and condenser assembled set that I currently have installed. I also have the same supply of points, rotors, condensers, and coils. Only have 2 resistors though...

How frustrating. There are a lot of stories on 8N spark problems, but no notable solution Ive been able to dig up. I wonder If the igniton switches go flakey. ... There must be some key common issue that eludes. Good luck.

 

[careyo63]

Almost sounds like I would start from scratch and Replace all the Ing. System. With new parts and rewire it. Big plus when I seen my 2000 On CL. was already converted to 12V.. I can honestly say of all the equipment,toys, etc. I never had A 6V. Electrical system. And seems odd that low voltage is a possible problem. Interesting!

 

[jimjumper]

If I am looking at these diagrams correctly, the only difference in the physical wiring between it having a cutout and it having a VR, is that 1 wire comes off the generator to the cutout and 1 wire to the mounting block vice 3 wires from the generator to the VR and 1 wire to the mounting block. So, when the tractor is running, there should be 7+ volts across that single wire regardless VR or cutout? Because I currently have no voltage there.

 

[jimjumper]

Ok, I'm back at it! I was correct, the generator was fried and not producing anything. Of course, that means the replacement which took a week was damaged in shipment so another week to send a replacement to the replacement.
Put the battery on a charger but it only shows maybe a half charge after 6 hours. Battery tester showed good but under load got a "low" reading. I am assuming the battery is bad? Wouldn't surprise me with the number of times I've taken it to totally dead working working on this beast with the generator not working.
Installed the generator and cutout and started it. Ammeter showed 2-3 amps when I increased the power from idle and that increased to 8-9 at full rpm's so I assume the generator is working. And I am finally getting decent spark across the spark checker but the generator does seem to run a little warm, as in, too hot to keep my hand on it more 10-15 sec. Would that be caused by a bad battery? Since the generator is now powering the coil, points, and plugs?
Seems to run fine until I put a load on it. I have a brush mower hooked up and if I let out the clutch too quickly it will stumble and die. The same if I go to drive it, as soon as the governor starts to increase it stumbles and usually dies. I have immediately (within seconds) checked the fuel and get good flow but I experimented with the carb plug and if I am at full power and remove the plug I don't even get a drop of fuel and then of course it shuts down when it gets air thru the plug hole. I have the idle jet at 3/4 turn and 5 turns out on the main jet. If it dies from being put under load, it usually takes 1-2 minutes before it will start again. Not enough fuel to the carb maybe? I have managed to drive it a little bit by by very! slowly letting out the clutch and getting it rolling without it dying but any little hill or throttle variation and its starts to stumble. Governor maybe?
So basically I'm back to where I was when I finally got it to start. Most of the diagnostics at this point is replacing parts and I have enough of the electrical parts to do another tractor. Haven't replaced much of the fuel parts although it does have a new carb and , as I've discovered, getting working parts is hit or miss.
Any ideas? Or should I replace the battery next and possibly try another carb? Maybe a new fuel line and shut-off valve as well? Although, when I take the fuel line off the carb I get plenty of fuel.
I'm about stumped!

 

[CalG]

just get a new battery and see. It's a small sum considering all the troubles you have.
6V doesn't give a lot of overhead for when things get weak.

Points and condenser still are suspect.

CLEAN POINTS, .015" gap! good plugs, and a known good condenser.

I know, that last one is tough.

I just went through this with a magneto ignition. But now all is good!

 

[EdGooding]

I have immediately (within seconds) checked the fuel and get good flow but I experimented with the carb plug and if I am at full power and remove the plug I don't even get a drop of fuel and then of course it shuts down when it gets air thru the plug hole

What is your definition of "good flow?" When you say "plug" are you talking about the bolt in the bottom of the fuel bowl in your carb?