Table 7-2. Engine Conditioning - CONT
Step 16. Engine Backfire
Place turbosupercharger in OFF
Test - continued
position. Carburetor air filters
should be by passed.
Set engine at specified rpm setting.
Move carburetor mixture control to
AUTO-LEAN. Move ignition switch
from BOTH to RIGHT and then to
LEFT for a sufficient length of time
in each position to permit engine
operation to stabilize. When moving
ignition switch from BOTH TO RIGHT
or LEFT, a high rmp drop will nor-
If the engine does not backfire from
either switch position, it is considered
satisfactory in this test. If it backfires,
one or more phases of engine
operation are not correct.
Step 17. Ignition
Set engine speed at specified rpm
Momentarily move Ignition switch
to OFF and determine that engine
completely ceases firing. Return
switch to BOTH as rapidly as possible
to eliminate possibility of backfiring.
Air Crew or
Check master switch same way.
Step 18. Spark Plug
Make cold cylinder check. Replace
only defective plugs and repeat
steps 6 through 16.