Black Max BM5020 Operator's Manual page 34

CLEANING THE ENGINE
See Figures 65 - 66.
Clean the cylinder fins and flywheel fins with com-
pressed air or a brush periodically. Dangerous over-
heating of the engine may occur due to impurities
on the cylinder.
WARNING:
Never run the saw without all the parts, including
the clutch cover and starter housing, securely in
place. Operating the saw without all parts securely
in place can result in death or serious personal
injury.
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 techni-
cians perform this service.
CHECKING THE FUEL FILTER
See Figure 67.
Check the fuel filter periodically. If contaminated or
damaged, have fuel filter replaced by an authorized
service center.
REPLACING THE SPARK PLUG
See Figure 68.
This engine uses a Champion RCJ6Y or a RYOBI
AC00160A spark plug with .025 in. electrode gap.
Use an exact replacement and replace every 25
hours or more frequently, if necessary.
NOTICE:
Allow engine to cool before removing spark plug.
Removing spark plug from a hot engine can cause
serious damage to the chain saw.
 Loosen the spark plug by turning it counterclock-
wise with the combination wrench provided or
other appropriate socket wrench.
 Remove the spark plug.
 Hand thread the new spark plug, turning it clock-
wise. Tighten securely with wrench.
MAINTENANCE
CYLINDER
CLEAN
FLYWHEEL FINS
Page 34 — English
CLEAN
FINS
FUEL FILTER
Fig. 65
Fig. 66
Fig. 67
Fig. 68