Ryobi RY905500E Operator's Manual page 21

SPARK PLUG MAINTENANCE
See Figure 19.
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.
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.
SPARK ARRESTOR
See Figure 20.
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 au-
thorities. Contact customer service or a qualified service
center to purchase a replacement spark arrestor.
 Inspect the spark arrestor screen for breaks or holes.
Replace if necessary.
 Use a brush (not provided) to remove carbon deposits
from the spark arrestor screen as needed.
MAINTENANCE
DRAINING FUEL TANK/CARBURETOR
See Figures 21 - 23.
To help prevent gum deposits in the fuel system, drain the
fuel from the tank and carburetor before storing.
DRAINING THE FUEL TANK
 Place the engine switch/fuel valve/choke lever in 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 (not provided) over the
petcock, and place the other end in a fuel container large
enough to catch the fuel being drained from the tank.
 Place the engine switch/fuel valve/choke lever in the RUN
position.
 When the fuel has drained from the tank, place the engine
switch/fuel valve/choke lever in OFF position and reinstall
fuel line securely onto the petcock.
DRAINING THE CARBURETOR
 Place the engine switch/fuel valve/choke lever in 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.
REPLACING FUEL FILTER
See Figure 24.
Occasionally the fuel filter may become clogged and need
to be replaced. To purchase a replacement fuel filter, contact
customer service or a qualified service center.
NOTE: Fuel tank must be empty before replacing fuel filter.
Run unit until tank is empty, if needed, or inspect filter prior
to fill-up.
 Place the engine switch/fuel valve/choke lever in the OFF
position.
 Remove the fuel line from both sides of the filter by
squeezing the ends of the retaining clip with pliers.
 Slide the fuel line off.
 Replace with new fuel filter.
 Reinstall fuel lines to new fuel filter.
Page 17 — English