Here is a look at this little old beast.
Here's a closer view of the carburetor.
I removed the carb from the tank and sprayed it thoroughly with carb cleaner, into little holes under the diaphragm, up the two pipes.
I flushed out the gas tank. Even though I had put in a quarter tank or so of new gas, that new gas I emptied while I was cleaning stuff was milky and terrible looking. I discarded it and flushed fresh gasoline around in the tank and emptied it about a half dozen times.
After assembly I got it started easily, but now no matter what I do with the throttle lever, I cannot get it running above a putt-putting idle. If I manually tug on the throttle with needle-nose pliers down at the carburetor, it goes barely faster.
I had this speed problem before, but not this bad. The air filter is clean, and when I remove it while the engine is running, I can hear a very small, perceptible RPM increase.
The exhaust was showing lightly black, so I turned that big carburetor jet screw a quarter turn tighter then a half turn. Again, not much of a change in RPM and exhaust was still lightly black.
It does not turn the tine fast enough to till soil.