I rebuilt my Dad's old 1949 Wizard WF4 (new points, condensors, coils, plug wires, carb kit, etc.) and it runs fine from the "start" position to full speed. At the "idle" setting, the engine will run a little while and then quit (like it's running out of gas). I can't seem to adjust it where I can get a good, slow idle.
Tillotson AJ series carburetors are die cast zinc alloy...as long as soaked with gas/oil mixture they
seem to last okay...BUT the metal does not hold
up well against moisture...internal passages prone
to clogging and/or change in critical sizes which
MAY be your problem. Cleaning out passages may help
but you need to use correct size number drill for
each passage per manual. One of the passages is
sealed with a lead pellet and another is sealed
with a welch plug....for which you will need replacements...remove and replace correctly.
In order of severity...
1)Spray carb cleaner is adequate to clean off gummy
fuel residue and grime.
2)Disassembly and soaking in the toxic carb cleaner will help many rough looking carburetors
3) Sometimes rodding out the passages will help if
the internal passages have not corroded away to
white powder and altered critical sizes or destroyed
4)Easy way out is a better carburetor.
Carburetors often found at meets...sometimes the ones
you want and sometimes not. If you do not have experience doing total rebuild pick up a couple
cheap junkers and practice...
Each of the gravity feed AJ series carburetors looks about the same but there are various changes between model (numbers stanped on each) Some changes are external parts other changes may be internal Best not to mix parts so work on one carburetor at a time.
Once you have worked out problems with carburetor
and installed it on engine...
Preliminary settings of idle 1 turn and hi speed needles 1 1/2 turns out from lighly seated.
Final settings done with motor warmed up and running in tank or on boat (preferred)
Once set further adjustment usually not needed as
long as gas/oil ratio in fuel mixture is consistant.
Antique long stored outboard motors can and do present
interesting problems...solutions to which can seldom
be found in manual.