Carburetor Adjustment - Ryobi 330B, 340BV Operator's Manual

MAINTENANCE AND REPAIR INSTRUCTIONS
6. Squeeze the filter to spread the oil (Fig. 20).
7. Reinstall the filter (Fig. 17, Pg 15)
8. Reinstall the carburetor/air filter cover and screws
(Fig. 16, Pg 15). Do not over tighten.
NOTE: Operating the unit without the air filter or
carburetor/air filter cover assembled will
VOID the warranty.
Fig. 20

CARBURETOR ADJUSTMENT

The idle speed of the engine is adjustable , the air filter
cover must be removed to do so. Only make adjust-
ments while the unit is assembled as a blower.
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. 11.
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. 14.
Adjust Idle Speed Screw
WARNING: The unit will be running during
idle speed adjustments. Wear protective
clothing and observe all safety instructions
to prevent serious personal injury.
Also, Do not set unit on any surface except a
clean, hard area during these adjustments.
Debris such as gravel, sand, dust, grass, etc.
could be picked up by the air intake and
thrown out by the discharge opening,
damaging unit, property, or causing serious
injury to bystanders or operator.
16
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 with the throttle
control in fast for a minute to warm up. See
Starting/Stopping Instructions, Pg. 12.
2. Shut the unit off and remove the carburetor/air filter
cover. See steps 1 and 2 of Air Filter Maintenance
Pg. 14 .
3. Restart the unit, move the throttle control to the idle
position. If the engine stops, insert a small phillips or
flat blade screwdriver into the idle speed screw
(Fig. 21). Turn the idle speed screw in, clockwise, 1/8
of a turn at a time (as needed) until the engine idles
smoothly.
4. If the engine seems to idle fast, turn the idle speed
screw counterclockwise 1/8 of a turn at a time
(as needed), to reduce idle speed.
5. Before reinstalling the carburetor/air filter cover, turn
the idle speed screw in, clockwise, 1/8 of a turn. This
will compensate for the speed reduction when the
carburetor/air filter cover is back in place.
6. Reinstall the filter (Fig. 17, Pg. 15), carburetor/air
filter cover and screws (Fig. 16, pg. 15).
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 unit checked and adjusted by an authorized
service dealer.
Primer Bulb
Idle Speed
Screw
Choke
Control
Fig. 21