muenster8n
New User
All, as with several recent posts, I'm new to tractors in general. I recently took a 1950 8N on trade with a fairly nice brush hog. The tractor ran, but was very hard to start. I ran through a fairly typical "tune up" procedure as follows (questions at the bottom of the post).
- Pulled spark plugs (they were old). Caked with carbon, replaced with Autolite 437's gapped to .015
- I replaced the wires as the insulation was cracked
- Replaced the points, cap & rotor. Gapped points to .025
- Replaced battery (the old one would not hold a charge, tested bad)
I have not yet removed & cleaned the carb. I have not yet adjusted the carb (trying to diagnose one thing at a time). Now when I attempt to start the tractor, it appears that I get intermittent and/or no spark. I pulled one of the wires and attempt to get an arc across a ground while trying to start it and no spark. I got out my trusty multimeter and traced the various wires back to the battery source. On the lower side (distributor side) of the coil, I get an intermittent 6v. The system was converted to 12v battery source some years ago, but has a 6v coil. I replaced the coil with a 6v coil and re-measured. I get the same result: intermittent 6v. From the battery forward, I get 12v all the way to the main resistor. On the back side of the main resistor, I get an intermittent (sometimes non-existent) 12v. This appears to be the original resistor. So...
Question 1: Can the main resistor cause a no start by providing low or intermittent voltage to the coil? I'm not sure how sensitive the ignition + timing system is to voltage drops.
Question 2: The original exhaust was a vertical style with a rather large hole in it. I ordered a replacement that is a horizontal unit. Are they interchangeable?
As an aside, the tractor appears to be running very rich, but I'm trying to get it to a known state where it runs consistently before I start adjusting the fuel system.
Thanks!
- Pulled spark plugs (they were old). Caked with carbon, replaced with Autolite 437's gapped to .015
- I replaced the wires as the insulation was cracked
- Replaced the points, cap & rotor. Gapped points to .025
- Replaced battery (the old one would not hold a charge, tested bad)
I have not yet removed & cleaned the carb. I have not yet adjusted the carb (trying to diagnose one thing at a time). Now when I attempt to start the tractor, it appears that I get intermittent and/or no spark. I pulled one of the wires and attempt to get an arc across a ground while trying to start it and no spark. I got out my trusty multimeter and traced the various wires back to the battery source. On the lower side (distributor side) of the coil, I get an intermittent 6v. The system was converted to 12v battery source some years ago, but has a 6v coil. I replaced the coil with a 6v coil and re-measured. I get the same result: intermittent 6v. From the battery forward, I get 12v all the way to the main resistor. On the back side of the main resistor, I get an intermittent (sometimes non-existent) 12v. This appears to be the original resistor. So...
Question 1: Can the main resistor cause a no start by providing low or intermittent voltage to the coil? I'm not sure how sensitive the ignition + timing system is to voltage drops.
Question 2: The original exhaust was a vertical style with a rather large hole in it. I ordered a replacement that is a horizontal unit. Are they interchangeable?
As an aside, the tractor appears to be running very rich, but I'm trying to get it to a known state where it runs consistently before I start adjusting the fuel system.
Thanks!