Homelite UT10012 Operator's Manual page 30

CLEANING THE ENGINE
See Figures 67 - 68.
Clean the cylinder fins and flywheel fins with compressed air
or a brush periodically. Dangerous overheating of the engine
may occur due to impurities on the cylinder.
WARNING
Never run the saw without all the parts, including the
drivecase cover and starter housing, securely in place.
Because parts can fracture and pose a danger of thrown
objects, leave repairs of the flywheel and clutch to factory
trained authorized service center personnel.
NOTE: If you notice a power loss with the gas-powered
tool, the exhaust port and muffler may be blocked with
carbon deposits. These deposits may need to be removed
to restore performance. We highly recommend that only
qualified service technicians perform this service.
CHECKING THE FUEL FILTER
See Figure 69.
Check the fuel filter periodically. Replace it if contaminated
or damaged.
REPLACING THE SPARK PLUG
See Figure 70.
This engine uses a Champion RCJ-6Y with .025 in. electrode
gap. Use an exact replacement and replace every 50 hours
or more frequently, if necessary.
n Loosen the spark plug by turning it counterclockwise with
a wrench.
n Remove the spark plug.
n Hand thread the new spark plug, turning it clockwise.
Tighten securely with wrench.
NOTE: Be careful not to cross-thread the spark plug.
Cross-threading will seriously damage the cylinder.
MAINTENANCE
CLEAN FLYWHEEL
30
FINS
FUEL FILTER
CLEAN
CYLINDER FINS
Fig. 67
Fig. 68
Fig. 69
LOOSEN
TIGHTEN
Fig. 70