Continental Motors TSIOL-550-C Operation, Maintenance & Installation Manual page 124

Ignition
2. Slowly turn crankshaft in opposite direction of
normal rotation until the piston lightly touches the
TDC locator.
3. Observe the reading on the disc under the pointer
and move the disc exactly one half of the number
of degrees observed toward the top center mark.
This will be one half the number of degrees
remaining of 360 degrees of crankshaft rotation.
You have now located top dead center.
8-8
FIGURE 8-4. TIMING PROCEDURE STEP 2