Carburetor Adjustment - Ryobi 780r Operator's Manual

MAINTENANCE AND REPAIR INSTRUCTIONS

CARBURETOR ADJUSTMENT

The idle speed of the engine is adjustable
though the Air filter/muffler cover (Fig 41).
NOTE: Careless adjustments can seriously
damage your unit. An authorized
service dealer should make carburetor
adjustments.
Check Fuel Mixture
Old and/or improperly mixed fuel is usually the
reason for the unit not running properly. Drain
and refill the tank with fresh, properly mixed fuel
prior to making any adjustments. Refer to
Oil and Fuel Information, Pg. 15.
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 Pg. 24.
Adjust Idle Speed Screw
WARNING: The cutting attachment
may be spinning during idle speed
adjustment. Wear protective clothing
and observe all safety instructions to
prevent serious personal injury.
If after checking the fuel mixture 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.
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 air filter/muffler cover (Fig. 41). Turn the
idle speed screw in, clockwise, 1/8 of a turn
at a time (as needed) until the engine idles
smoothly.
NOTE: The cutting attachment should not
rotate when the engine idles.
3. If the cutting attachment rotates 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 mixture, cleaning the air filter,
and adjusting the idle speed screw should solve
most engine problems.
If not and:
• The engine will not idle,
• The engine hesitates or stalls on
acceleration,
• There is a loss of engine power,
have the carburetor adjusted by an authorized
service dealer.
WARNING: When the unit is turned
off make sure the cutting attachment
has stopped before the unit is set
down to prevent serious personal
injury.
Idle Speed Screw
Fig. 41
25