Small Engines (Lawn Mowers, etc.): Tecumseh Timing for old engine HS40-55388C, engine woes, continuity tester

Question
Thanks for the great site and your dedication to helping others out with their engine woes!
I am trying to get a Tecumseh 4hp engine running smoothly on a 1972 Rupp Roadster2 minibike.  This engine was not run much in the last 30 years so I have changed the oil twice to flush out some sludge clumps.  The old oil did not appear to contain much of any metal flecks and the engine does have good compression.  I purchased a new service carb for it and have adjusted the screws as recommended in other answers here but am still getting some white smoke.  The points were replaced and set to .020".
How do I set the timing for this engine?  I do not know the BTDC spec for this engine so I have used a continuity tester by turning the stator clockwise to find the points closed position and then turning it counter-clockwise to get the break-open position and have tightened the stator there.  Is this correct or is there another method for timing that I can try?  It just doesn't seem correct due to the engine not being able to hold a steady idle.
Best regards

Answer
 Hello Darryl:

 The Unsteady idle can be caused by 2 things. 1- the Idle Governor Spring could be broken. 2- The low speed Fuel Mixture Screw is not Adjusted properly.  The The Flywheel Key times the Engine. The Coil is set to .20 from the Flywheel. The Smoke may be where the Crankcase Vent isnt Working properly.  Hope This Helps.

 Good Luck

 Respectfully

 John