Carburetor Adjustments; Models Tc-300 & Tc-400 (Walbro Carburetor) - Toro 51603 Maintenance And Repair Manual

MAINTENANCE PROCEDURES
3.
Adjust Idle First: With engine idling, rotate the
Low Speed Screw (L) for the leanest fuel mixture
that allows stable idle, and acceleration without
hesitation.
4. If necessary, idle speed can be increased by
turning the idle stop screw clockwise (Fig. 12).
2. Low
Speed Screw
(L) (Fig. 13)
Close the screw
by gently rotating
it
clockwise until a light seating
resistance is felt. Next, rotate the screw 1 1/4-1 1/2
turns counterclockwise.
3.
Idle Screw (Fig.
13)
Close
the screw by rotating
it clockwise until the screw contacts the throttle
lever After contact is made, continue turning
screw
11/2-21/2
additional turns.
Figure 12
5.
Hold the throttle trigger at the maximum speed
position and adjust the High Speed Screw (H) for
maximum engine speed.
6. Recheck the idle adjustment.
CARBURETOR ADJUSTMENT MODELS TC-
300,
TC-400 WITH WALBRO CARBURETOR
IMPORTANT: Do not close the carburetor adjusting
screws too tightly as damage to the screws and seats
may result. Also, the correct amount of line must be
fed from the trimmer spool before adjusting the
carburetor to ensure that the engine is adjusted for
operation while under load.
1. High Speed Screw (H) (Fig. 13) Close the screw
by gently rotating
it
clockwise until a light seating
resistance is felt. Next, rotate the screw one turn
counterclockwise.
Figure 13
NOTE: Although these settings are approximate,
the should be able to be started. Further
adjustments of the carburetor may be necessary
to obtain the best performance for your area.
Steps 4-6 should be followed to fine tune the
carburetor.
When making these adjustments,
turn the screws 1/8 of a turn at a time and wait for
the 'engine to respond to the change.
6