Ryobi 510r - Manual (Page 16)

MAINTENANCE AND REPAIR INSTRUCTIONS
16
Remove Screws
Fig. 27
Engine Cover
2. Remove the two (2) screws on top of the engine
cover with a phillips screwdriver (Fig. 28).
3. Remove the screw on back of the engine cover
(Fig. 29).
Fig. 28
Muffler Cover
Engine Cover
Muffler
ROCKER ARM CLEARANCE
This procedure requires disassembly of the engine. If
you feel unsure or unqualified to perform this, take the
unit to an authorized service center.
NOTE: Inspect the valve to rocker arm clearance with a
feeler gauge after the first 10 hours of operation
and then every 25 hours of operation thereafter.
• The engine must be cold when checking or adjusting
the valve clearance.
• This task should be performed inside, in a clean, dust
free area.
1. Remove the muffler cover by pressing down on the
corner with a flat blade screwdriver (Fig. 27). Slide
the notches on the sides of the muffler cover over
the tabs on the engine cover and remove.
Top View Of
The Engine
CARBURETOR ADJUSTMENT
The idle speed of the engine is adjustable. Reach the
idle adjustment screw though a hole in the top of the
engine cover (Fig 26).
NOTE: Careless adjustments can seriously damage your
unit. An authorized service dealer should make
carburetor adjustments.
Check Fuel
Old fuel is usually the main reason for the unit not
running properly. Drain and refill the tank with clean,
fresh unleaded fuel prior to doing any adjustments. Refer
to Oil and Fuel Information.
Clean Air Filter
The condition of the air filter is important to the
operation of the unit. A dirty air filter will restrict air flow
and change the air/fuel mixture. This is often mistaken
for an out of adjustment carburetor. Check the condition
of the air filter before adjusting the idle speed screw.
Refer to Air Filter Maintenance.
Adjust Idle Speed Screw
WARNING: This unit needs to run during idle
speed adjustment. Wear protective clothing
and observe all safety instructions to prevent
serious personal injury.
If after checking the fuel and cleaning the air
filter the engine still will not idle, adjust the idle speed
screw as follows:
1. Start the engine and let it run at a high idle for a
minute to warm up.
NOTE: Ensure the tines are not in contact with the
ground when adjusting the idle.
2. Release the throttle trigger and let the engine idle. If
the engine stops, insert a small phillips or flat blade
screwdriver into the hole in the engine cover
(Fig. 26). Turn the idle speed screw in, clockwise, 1/8
of a turn at a time (as needed) until the engine idles
smoothly.
NOTE: The tines should not rotate when the engine idles.
3. If the tines rotate when the engine idles, turn the idle
speed screw counterclockwise 1/8 of a turn at a
time (as needed), to reduce idle speed.
Checking the fuel, cleaning the air filter, and adjusting
the idle speed screw should solve most engine
problems.
If this does not solve the problem and all of the following
are true:
• The engine will not idle
• The engine hesitates or stalls on acceleration
• There is a loss of engine power
Have the unit checked and adjusted by an authorized
service dealer.
Idle Adjustment Screw
Fig. 26