Frontier ST0521E, Operator'S Manual

Page: 23 / 44

MAINTENANCE
23
MTF-0410107C
TO ADJUST THE CARBURETOR
The carburetor is not adjustable. Engine performance
should not be affected at altitudes up to 7,000 feet. For
operation at higher elevations, contact your nearest autho-
rized service center.
IMPORTANT: Never tamper with the engine governor,
which is factory set for proper engine speed. Over-speed-
ing the engine above the factory high speed setting can be
dangerous. If the engine-governed high speed needs an
adjustment, contact an authorized service center. They
have the proper equipment and experience to make any
necessary adjustments.
TO ADJUST OR REPLACE THE SPARK PLUG
Check the spark plug every twenty-five ( 25 ) hours. Re-
place the spark plug if the electrodes are pitted or burned
or if the porcelain is cracked.
The spark plug is housed in the engine compartment under
the top cover and cannot be seen under normal condi-
tions.
WARNING:
STOP the engine. Wait for it to cool
before removal of spark plug.
CAUTION: DO NOT clean the plug with abrasives.
1. Remove the fuel cap (see Figure 24).
2. Remove the screws from the shroud. Remove the
shroud. Install the fuel cap.
3. Disconnect the spark plug wire (see Figure 25).
4. Clean the area around the spark plug base to prevent dirt
from entering the engine when the spark plug is re-
moved.
5. Remove the spark plug .
6. Check the spark plug . If the spark plug is cracked,
fouled or dirty, it must be replaced .
7. Set the gap between the electrodes of the new spark
plug at 0.030 inch (Figure 26).
8. Install the spark plug in the cylinder head and firmly tight-
en. Recommended torque is 18 to 20 foot pounds. Attach
the spark plug wire.
9. Remove the fuel cap and install the shroud (see
Figure 24).
10. Install the fuel cap.
Figure 24
Fuel Cap
Shroud
Figure 25
Spark Plug
Wire
Spark
Plug
Figure 26
.030” (0.76 mm) Gap