Ryobi 310r - Manual (Page 14)

3. Initial High Speed Mixture and Idle Speed Mixture
Needle Settings: Insert the screwdriver through the
hole at the back of the top handle (Fig. 32). Turn both
the high speed mixture and idle speed mixture
needles out (counterclockwise) until the limiter
caps stop.
4. Start the engine and let it run for a minute.
5. Release the throttle trigger and let the engine idle. If
the engine stops, turn the idle speed screw (Figs. 30
and 31) in (clockwise) 1/8 turn at a time (as required)
until the engine idles.
NOTE: Forcing the limiter caps with a
screwdriver will damage the needle tips
and the seat in the carburetor body.
6. Final Idle Speed Screw and Idle Speed Mixture
Needle Settings: Adjust the idle speed screw and idle
speed mixture needle for smoothest engine idle.
a. Turn the idle speed mixture needle (Figs. 30 and
31) in (clockwise) until you hear the fastest idle;
then turn the needle out (counterclockwise) 1/8
turn.
b. Squeeze the throttle trigger. If the engine falters
or hesitates as it accelerates, turn the idle speed
mixture needle (Figs. 30 and 31) out
(counterclockwise) 1/16 turn at a time until the
engine accelerates rapidly.
c. If the idle speed changes significantly because of
Steps a and b, readjust the idle speed screw
(refer to Step 2).
7. Final High Speed Mixture Needle Adjustment:
a. High speed mixture needle adjustment is not
recommended without a precision high speed
tachometer.
b. The factory presets the high speed mixture
needle at 1-1/4 turns out from the closed
position. Your unit should perform well at this
setting. If additional adjustment of the high speed
mixture needle is required, contact your local
authorized service dealer.
14
MAINTENANCE AND REPAIR INSTRUCTIONS (Continued)
Fig. 31
Fig. 29
Fig. 30
WALBRO CARBURETOR
Throttle
Lever
Idle Speed
Screw
High Speed
Mixture Needle
Idle Speed
Mixture Needle
Idle Speed
Screw
Throttle
Lever
High Speed
Mixture Needle
Idle Speed Mixture Needle
ZAMA CARBURETOR
NOTE: If the limiter caps are removed at any
time, your unit will no longer meet the
1995 California emission regulations and
you will void the warranty.