Black Max BM907500BT Operator's Manual page 21

SPARK PLUG MAINTENANCE
See Figure 18.
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 replacement spark
plug, see Product Specifications earlier in this manual
or the accompanying engine manual, if applicable.
 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.
 Reinstall the spark plug cap.
SPARK ARRESTOR
See Figure 19.
NOTICE:
This product is equipped with a spark arrestor that has
been evaluated by the USDA Forest Service; however,
product users must comply with Federal, State, and
local fire prevention regulations. Check with appropriate
authorities. Contact customer service or a qualified
service center to purchase a replacement spark arrestor.
 Inspect the spark arrestor for breaks or holes. Clean or
replace if necessary.
 Use a brush (not provided) to remove carbon deposits
from the spark arrestor screen as needed.
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
performance. We highly recommend that only qualified service
technicians perform this service.
MAINTENANCE
DRAINING FUEL TANK/CARBURETOR
See Figures 20 - 22.
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 on/off switch OFF.
 Turn the fuel valve to the OFF position.
 If necessary, push the fuel valve knob through the generator
housing and pull down slightly to gain access to the hose
barb.
 Remove the fuel line from the hose barb by squeezing
the ends of the retaining clip and sliding the fuel line off.
NOTE: Make sure you are removing the fuel line that runs
between the fuel valve and the carburetor, NOT the line
that runs between the fuel valve and the fuel tank.
 Install one end of a drain line (not provided) over the hose
barb, 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 hose barb.
 If previously removed, reinstall fuel valve knob in generator
housing. Push forward until knob snaps securely into
position.
DRAINING THE CARBURETOR
 Turn the on/off switch OFF.
 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.
TRANSPORTING
 Turn the on/off switch OFF. Disconnect any equipment
that is plugged into the generator.
 Verify the fuel valve is in the OFF position.
 Allow 30 minutes of "cool down" time before transporting
the machine. Make sure engine and exhaust of unit are
cool.
 For security, insert the pins to secure the handle before
transporting.
 Tilt the machine toward you until it balances on the wheels,
then roll the machine to the desired location.
 If transporting in a vehicle, drain the fuel tank, close fuel
valve and securely restrain the generator.
 Provide a plastic sheet or absorbent pad below the
generator to catch any drips of fuel or lubricant.
Page 17 — English