This is a 1949 front-distributor 8N model. It is not a show tractor -- it is a durable and trusted tool.
Original options:
- Sherman Hi/Lo transmission
- Allied hydraulic trip-bucket loader driven by front-shaft pump
Recent maintenance:
- 2016. Converted professionally to 12V and electronic ignition. I think they used the kit available at YT with the cylinder-shaped coil
- 2017. Replaced main hydraulic cylinder, washers, overpressure valve, and some seals.
- 2019 summer. Replaced external hydraulic lines and added two-gang hydraulic controller. one for original bucket, the second for a hydraulic 3-point toplink
Late this fall, it started running rough under load, and would not get up to RPM even with open throttle. So, I started going though everything methodically.
0. Replaced sparkplugs with NEW (Autolite 437s) and changed engine oil with generic 10W30.
1. Complete carb rebuild (original body, new seals and pins and all)
2. Drained fuel tank twice and blew out fuel line. Cleaned and replaced filter in sediment bowl.
3. Replaced starter solenoid with NEW. (It shorted out after 70 years when I was testing the new carb)
4. Replaced governor with NEW. (the original one was probably fine actually)
5. Replaced manifold and gaskets with NEW. I sometimes saw exhaust around the manifold in cold weather, so was wondering about a vacuum leak. (but the spray test never made any change)
6. Replaced crappy straight-tube muffler with a new compact car muffler.
Now I can hear the engine noises better.
7. Added a digital proofometer that picks up from plug#4 so I can watch engine RPMs more accurately.
Wow, it starts great and can run from 500rpm to almost 3000rpm amazingly well. Great power delivery. (I don't run it over 2400rpm except if I need a quick kick to get out of a hole. Muffler starts to glow pretty quick lick a hotrod up there.)
OK, sounds fantastic!
but then.... I get bogged down in a deep icy snow drift, and it goes back to this rough-running low-power behavior. Idles a little rough, and wont go over 800 or 1000rpm according to the plug #4 tach. Almost no throttle response.
Driving along a clear road, it seems to run fine. Hit a big bump or put the engine under heavy load, and it seems to get caught like this.
Sometimes I can kill it and restart, or I can try to rev up-and-down a little, and it will come back to running normally.
Some interesting tidbits:
When it's running funny, I can short each of the spark plug wires with a wrench, and I get spark to the engine block.
BUT! When I short plug #4, the engine dies immediately. I wonder if it's just not firing on a couple cylinders, then comes back somehow. But, I have at least some voltage to each plug stem.
Do these ideas seem sane? Any other ideas?
1. Maybe moisture or gunk in the distributor, enough to reduce spark voltage?
2. Maybe a weak or loose connection on the ignition coil?
3. Maybe stuck valves?
Original options:
- Sherman Hi/Lo transmission
- Allied hydraulic trip-bucket loader driven by front-shaft pump
Recent maintenance:
- 2016. Converted professionally to 12V and electronic ignition. I think they used the kit available at YT with the cylinder-shaped coil
- 2017. Replaced main hydraulic cylinder, washers, overpressure valve, and some seals.
- 2019 summer. Replaced external hydraulic lines and added two-gang hydraulic controller. one for original bucket, the second for a hydraulic 3-point toplink
Late this fall, it started running rough under load, and would not get up to RPM even with open throttle. So, I started going though everything methodically.
0. Replaced sparkplugs with NEW (Autolite 437s) and changed engine oil with generic 10W30.
1. Complete carb rebuild (original body, new seals and pins and all)
2. Drained fuel tank twice and blew out fuel line. Cleaned and replaced filter in sediment bowl.
3. Replaced starter solenoid with NEW. (It shorted out after 70 years when I was testing the new carb)
4. Replaced governor with NEW. (the original one was probably fine actually)
5. Replaced manifold and gaskets with NEW. I sometimes saw exhaust around the manifold in cold weather, so was wondering about a vacuum leak. (but the spray test never made any change)
6. Replaced crappy straight-tube muffler with a new compact car muffler.
Now I can hear the engine noises better.
7. Added a digital proofometer that picks up from plug#4 so I can watch engine RPMs more accurately.
Wow, it starts great and can run from 500rpm to almost 3000rpm amazingly well. Great power delivery. (I don't run it over 2400rpm except if I need a quick kick to get out of a hole. Muffler starts to glow pretty quick lick a hotrod up there.)
OK, sounds fantastic!
but then.... I get bogged down in a deep icy snow drift, and it goes back to this rough-running low-power behavior. Idles a little rough, and wont go over 800 or 1000rpm according to the plug #4 tach. Almost no throttle response.
Driving along a clear road, it seems to run fine. Hit a big bump or put the engine under heavy load, and it seems to get caught like this.
Sometimes I can kill it and restart, or I can try to rev up-and-down a little, and it will come back to running normally.
Some interesting tidbits:
When it's running funny, I can short each of the spark plug wires with a wrench, and I get spark to the engine block.
BUT! When I short plug #4, the engine dies immediately. I wonder if it's just not firing on a couple cylinders, then comes back somehow. But, I have at least some voltage to each plug stem.
Do these ideas seem sane? Any other ideas?
1. Maybe moisture or gunk in the distributor, enough to reduce spark voltage?
2. Maybe a weak or loose connection on the ignition coil?
3. Maybe stuck valves?