Ryobi RY13016 - Manual (Page 15)

11 — English
MAINTENANCE
FUEL CAP, TANK, AND LINES
WARNING:
Check for fuel leaks. A leaking fuel cap, tank, or lines are a
fire hazard and must be replaced immediately. If you find
any leaks, correct the problem before using the product.
Failure to do so could result in a fire that could cause seri-
ous personal injury.
The fuel cap contains a non-serviceable filter and a check
valve. A clogged fuel filter will cause poor engine performance.
If performance improves when the fuel cap is loosened,
check valve may be faulty or filter clogged. Replace fuel cap
if required.
SPARK PLUG REPLACEMENT
See Figure 19.
This engine uses a Champion RY4C spark plug with 0.025 in.
electrode gap. Use an exact replacement and replace annually.

Remove the screw on back of the engine housing. This will
allow the engine housing to uncover as shown.
 Remove the spark plug wire.
 Loosen the spark plug by turning it counterclockwise with
a socket wrench.
 Remove the spark plug.
 Hand thread the new spark plug, turning it clockwise.
 Tighten with a socket wrench and torque to 170 in. lb.
minimum, 190 in. lb. maximum. Do not overtighten.
 Secure the engine housing back into place and return the
screw. Ensure that the housing is stable.
NOTICE:
Be careful not to cross thread the spark plug. Cross thread-
ing will seriously damage the product.
CHANGING ENGINE LUBRICANT
See Figure 20.
WARNING:
Do not change engine lubricant while it is hot. Accidental
contact with hot engine lubricant could result in serious
burns.
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 oil fill cap/dipstick.
 Tip the unit backward so the handles rest on the ground
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 unit to an upright position and refill with lubricant
following the instructions in the Adding/Checking Engine
Lubricant section previously in this manual.
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 21 - 23.
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.
 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 could result in serious injury
or property damage.