Black Max BM10680S Operator's Manual page 20

SPARK PLUG MAINTENANCE
See Figure 17.
The spark plug must be properly gapped and free of deposits
in order to ensure proper engine operation. To check:
 Remove the spark plug cap.
 Clean any dirt from around base of spark plug.
 Remove spark plug using wrench (not included).
 Inspect spark plug for damage, and clean with a wire
brush before reinstalling. If insulator is cracked or
chipped, spark plug should be replaced. For replace-
ment spark plug, see Product Specifications earlier in
this manual or the accompanying engine manual, if ap-
plicable.
 Measure plug gap. The correct gap is 0.028−0.031 in.
(0.7-0.8 mm). To widen gap, if necessary, carefully bend
the ground (top) electrode. To lessen gap, gently tap
ground electrode on a hard surface.
 Seat spark plug in position; thread in by hand to prevent
cross-threading.
 Tighten with wrench to compress washer. If spark plug
is new, use 1/2 turn to compress washer appropriate
amount. If reusing old spark plug, use 1/8 to 1/4 turn for
proper washer compression.
NOTE: An improperly tightened spark plug will become
very hot and could damage the engine.
CLEANING THE EXHAUST PORT AND
MUFFLER
Depending on the type of fuel used, the type and amount of
lubricant used, and/or your operating conditions, the exhaust
port and muffler may become blocked with carbon deposits.
If you notice a power loss with your gas-powered products,
you may need to remove these deposits to restore perfor-
mance. We highly recommend that only qualified service
technicians perform this service.
MAINTENANCE
SPARK ARRESTOR
See Figure 18.
 Inspect the spark arrestor for breaks or holes. Re-
place if necessary. To purchase a replacement spark
arrestor contact Blackmax customer service at
1-800-726-5760.
 Use a brush to remove carbon deposits from the spark
arrestor screen as needed.
DRAINING FUEL TANK/CARBURETOR
See Figures 19 - 20.
To help prevent gum deposits in the fuel system, drain the
fuel from the tank and carburetor before storing.
DRAINING THE FUEL TANK
 Turn the engine switch OFF ( O ).
 Turn the fuel valve to the OFF position.
 Remove the fuel line from the petcock by squeezing the
ends of the retaining clip and sliding the fuel line off.
 Install one end of a drain line over the petcock, and
place the other end in a fuel container large enough to
catch the fuel being drained from the tank.
 Turn the fuel valve to the ON position.
 When the fuel has drained from the tank, close the fuel
valve and reinstall fuel line securely on petcock.
DRAINING THE CARBURETOR
 Turn the engine switch OFF ( O ).
 Turn the fuel valve to the OFF position.
 Position a suitable container under the carburetor drain
screw to catch fuel; loosen the screw.
 Allow fuel to drain completely into container.
 Retighten drain screw.
NOTE: Consult hazardous waste management guidelines
in your area for the proper way to dispose of used fuel.
Page 16 — English