Hangar 9 Taylorcraft 20cc ARF Assembly Manual page 22

Step 2
On the upper line of the ignition measure 3/4-inch in
from the right (as viewed looking at the firewall). Make
a mark with a pencil. Measure 5/8-inch across on the
lower line and make a mark in the same manner.
Step 3
Use a 3/16-inch drill bit to make a hole at each mark.
Drill the holes so that they are located outside the
outline of the ignition unit placement.
22
Step 4
Use a ruler to measure 1-inch below the lower hole
drilled in Step 3 and mark the location with a pencil.
Step 5
Use a 1/4-inch drill bit to drill two holes next to each
other. Clean out the extra wood between the holes
with a hobby knife or file, forming a slot measuring
1/4 x 1/2-inches.
Step 6
Check that the battery lead from the ignition unit is
able to pass through the slot into the fuselage.
Step 7
Use an 11/64-inch drill bit to enlarge the holes for the
nylon pushrod tube housing.
Hangar 9 Taylorcraft 20cc Assembly Manual