This is the carb adjustment procedure from the Tecumseh Technicians handbook. It slightly differs from the above post way to adjust, But I agree it must be done with the engine cold for the final tweak. What I didn't quite understand was do you adjust the high speed screw while running wide open to get the most rpm or do you just adjust it for a smooth transition from idle to high speed? in the above post? The other thing is when you are adjusting the low speed you also might have to keep backing off the idle stop screw as you adjust the low speed screw if the idle keeps going higher it will start to engage the clutch. I am going to record my screw settings and try adjusting it both ways and see which is better.
DIAPHRAGM - SINGLE AND DUAL ADJUSTMENT
Turn the mixture adjustment screw(s) clockwise finger
tight, then one (1) turn counterclockwise. This setting
will allow the engine to be started so that the carburetor
can be fine tuned. Do not adjust the carburetor when
the engine is cold.
Start the engine and let it warm-up for approximately
5 minutes. If the engine falters or stops after the choke
lever is moved to the "OFF" position, turn the adjusting
screw 1/4 turn counterclockwise and restart the engine.
NOTE: On dual adjust, the first adjustment must be
made with the main mixture screw.
With the engine running, turn the mixture adjustment
screw clockwise until the engine starts to falter,
remember this location. Next turn the screw
counterclockwise until the engine starts to sputter or
drop in R.P.M., remember this location. Now turn the
screw clockwise until it is halfway between these two
locations. This will be the optimum carburetor setting.
With dual adjust carburetor, repeat the above steps
for the second (idle) mixture adjusting screw.
