STATIC TIMING OF MGA or MGB
WITH PETRONIX IGNITOR INSTALLED
(THIS IS FOR NEGATIVE GROUND SYSTEM)
Follow the instructions on installation of the Petronix Ignitor.
You can put the number one cylinder to TDC putting on the hand brake and put the car in neutral. Remove the number one cylinder spark plug and rotate the engine using wrench or hand crank until the number one cylinder shows compression.(I used a compression gage but I have removed the #1 spark plug and put my thumb over the hole and turned the crank until I feel compression then keep turning clockwise until the timing mark on the crank pulley lines up with the timing marks on the timing cover)
The timing mark on the crank pulley should be next to or close to the TDC timing pointer on the timing chain cover.
Now rotate the crank pulley clockwise until the timing mark is at (10 deg for MGB 7 deg for MGA) before top dead center.
Connect a test light(or if you want to use a volt meter set on 20 volt scale) one side to the negative terminal (-) of the coil and the other side to ground point
Loosen the clamp on the distributor so it can be rotated easily.
Switch on the ignition and rotate the distributor CLOCKWISE until the test light illuminates. Then rotate the distributor COUNTER CLOCKWISE until the test lamp goes out. Now rotate the distributor CLOCKWISE slowly until the test lamp just barely comes on.
That's it static timing is set for 10 or 7 deg before TDC on cylinder #1
Turn the ignition off. Tighten the nut down on the distributor clamp.
You can check your work by rotating the crank clockwise two full revolutions while watching the test lamp (with ignition on).
You should see the lamp light just as the crank pulley mark reaches the 10 or 7 deg before TDC mark is below the pointer.
If not, just set the crank at 10 or 7 deg before TDC, loosen the clamp
and repeat CCW 'til OFF and CW 'til ON.
BE CAREFUL NOT TO LEAVE THE IGNITION ON TO LONG EXCEPT DURING THE TEST.