Ryobi RY34000 - Manual (Page 12)

10 — English
MAINTENANCE
SPARK PLUG REPLACEMENT
This engine uses a Champion RY4C spark plug with .025 in. elec-
trode gap. Use an exact replacement and replace annually.
CHANGING ENGINE LUBRICANT
See Figure 12.
For best performance, engine lubricant should be changed after
every 25 hours of operation.
To change the engine lubricant:

Stop the engine and disconnect the spark plug wire. Allow
the engine to cool completely before proceeding.
 Remove the screw from the top engine cover and set
aside.
 Remove the screws from the bottom of the engine cover.
Remove the bottom cover and set aside.
 Remove the oil fill cap/dipstick.
 Tip power head on its side and allow lubricant to drain from
the oil fill hole into an approved container.
NOTE: Drain the lubricant while the engine is still warm
but not hot. Warm lubricant will drain quickly and more
completely.
 Return the power head to an upright position and refill with
lubricant following the instructions in the Adding/Checking
Engine Lubricant section previously in this manual.
 Reinstall the bottom engine cover. Replace the screws and
tighten securely.
 Replace the screw in the top engine cover and tighten
securely.
NOTE: Used lubricant should be disposed of at an approved
disposal site. See your local retailer for more information.
ADJUSTING CAMSHAFT-TO-ROCKER ARM
CLEARANCE
See Figures 13 - 15.
Inspect the camshaft-to-rocker arm clearance after every
25 hours of operation. This should be done in a clean, dust-
free environment.
NOTE: This procedure requires partial disassembly of the
engine. If you are unsure if you are qualified to perform this
operation, take the unit to an authorized service center.

Stop the engine and disconnect the spark plug wire. Allow
the engine to cool completely before proceeding.
 Remove the screw from the top engine cover. Remove engine
cover and set aside.
 Using a Torx screwdriver, remove the screw from the rocker
arm cover. Remove the cover and set aside.
 Position camshaft by pulling the recoil starter grip just until
the deep hole in the camshaft gear is located at the 6 o’clock
position as shown.
 Place the feeler gauge under each rocker arm and measure
the gap. The gap should be between .006 in. (0.15 mm) and
.008 in. (0.20 mm) for both rocker arms.
NOTE: Use a standard automotive feeler gauge. The .006
in. (0.15 mm) feeler gauge should slide between the rocker
arm and valve stem with a slight amount of resistance but
without binding. The 0.008 in. (0.20 mm) feeler gage should
not slide between the rocker arms and the cam lobes — it
should be held tight.
 If the valve clearance is not between .006 in. (0.15 mm) and
.008 in. (0.20 mm), the clearance should be adjusted as
follows:
• While holding a wrench on the flats of the adjusting
nut with one hand, loosen the retaining nut with a
second wrench as shown. Take care not to loosen
the stud.
• Rotate the adjusting nut until it touches the feeler gauge.
Once the gap setting is correct, hold the wrench on
the flats of the adjusting nut and retighten the retaining
nut securely.
 Adjust the second rocker arm, if necessary.
 Replace the rocker arm cover and screw; tighten securely.
 Replace the top engine cover and screw; tighten securely.
WARNING:
Ensure all engine cover and all engine parts are completely
and properly reassembled before starting engine. Failure
to correctly reassemble engine may result in serious injury
or property damage.
STORING THE PRODUCT
 Clean all foreign material from the product. Store idle unit
indoors in a dry, well-ventilated area that is inaccessible to
children. Keep away from corrosive agents such as garden
chemicals and de-icing salts.
 Abide by all ISO and local regulations for the safe storage
and handling of gasoline.
When storing 1 month or longer:

Drain all fuel from tank into a container approved for gasoline.
Run engine until it stops.
HIGH ALTITUDE ENGINE OPERATION
Please have an authorized service center adjust this engine if
it is to be run above 2000 feet. Failure to do so may result in
poor engine performance, spark plug fouling, hard starting,
and increased emissions. Carburetor adjustment by an autho-
rized service center will improve performance and allow that
this engine meets EPA (Environmental Protection Agency) and
California ARB (Air Resources Board) emission standards. An
engine adjusted for high altitudes can not be run at 2000 feet
or lower. In doing so, the engine will overheat and cause seri-
ous engine damage. Please have an authorized service center
restore high altitude modified engines to the original factory
specification before operating below 2000 feet.