Oscillating idle - 8N

[timsch]

Yes, Rodger, thanks for the heads-up. I was aware of that from looking into working on the governor from some other threads. When taking it apart I had it in mind and figured the shorter one would have been the one closer to the workings of the engine, and that turned out to be the case. That's how I'll remember it.

I only caught it because of you pointing out my likely issue with the bent rod, so I owe you a great Thanks, soaked. I owe a great deal of appreciation in general to YT and all of the helpful contributors here. I'd be nowhere on this tractor without y'all's help. So, hat tip to y'all.

 

[Tall T]

I recently cleaned the carb and attempted to adjust it after reinstallation. It starts easily with minimal choke, runs pretty well, but when I pull it down to idle, it oscillates. I don't recall it doing that years back. Here's a video of it, showing the governor arm moving back and forth. What could be the cause of this, assuming it's not typical.

Does it happen if your fuel shutoff is open exactly 2 turns?

I've had that engine "loping" when almost out of fuel
or when fuel delivery was being impeded somehow.

Another test would be to shut off the tank valve and gravity feed gas to the carb.
If it runs fine then it is fuel delivery TO the carb.

 

[timsch]

Roughly, not exactly. 4 flicks of the wrist. I've checked flow to/thru the carb and it's good.

 

[HarryVanderpool]

Low float level will cause loping as well.

 

[timsch]

carb was rebuilt recently and float level was checked, verified correct.

 

[Tall T]

Roughly, not exactly. 4 flicks of the wrist. I've checked flow to/thru the carb and it's good.

That sounds like one turn. I've tested it with the fuel line disconnected and max flow doesn't happen at only one turn.
Try exactly two as my NAA manual indicates. The knob is marked so you can keep track.

 

[timsch]

I'll keep that in mind, but I also keep in mind every time I open it that it is supposed to be 2-turns out, so I'm visualizing half a turn with each flick of the wrist. Should be pretty close. If it's being starved for fuel, I'd expect issues at higher throttle more than at idle, and that's not happening.