Echo CS-5100 - Manual (Page 13)

SERVICE INFORMATION
CS-4400
CS-5100 13
CS-5100
2-3 Adjusting carburettor
1. Start engine and warm it up well for 2 - 3 minutes
with cycle of 5 seconds at WOT (Wide Open Throttle)
and 10 seconds at idling.
2. Using 1.5 mm wide blade screw driver, adjust L
mixture needle to obtain maximum idle speed.
3. Set idle speed to 3,500 r/min by turning idle adjust
screw (in the range of 3,300 to 3,700 r/min allowable).
4. Turn L mixture needle anticlockwise to reduce
engine idle speed 1000 r/min to set idle speed in
the range of 2,300 to 2,700 r/min.
NOTE : Engine speed must be allowed to stabilize
a minimum of 20 seconds after each adjustment of
L mixture needle to assure accurate tachometer
readings.
5. Turn H mixture needle anticlockwise at WOT until
engine speed drops less than 12,000 r/min.
6. Adjust WOT engine speed in the range of 12,500
to 13,500 r/min by turning H mixture needle
clockwise.
NOTE : During H mixture needle adjustment, do not
run engine at high speed without load longer than
5 seconds.
7. If the engine speed at WOT is above 13,500 r/min,
adjust H mixture needle anticlockwise and set
maximum engine speed at less than 13,500 r/min.
8. After adjusting carburettor, Press the caps on L
and H mixture needles as shown.
9. Start engine again and make it sure engine runs
at idle speed in the range of 2,300 to 2,800 r/min
and at WOT engine speed in the range of 12,500 to
13,500 r/min. Also make it sure chain would not turn
at engine idle speed and suitable acceleration.
NOTE : Initial carburettor setting (Idle adjust screw,
L and H mixture needles) shown here is to start the
engine after restoration or carburettor change. Idle
adjust screw, L and H needles turn for designated
engine revolution through procedures indicated here
may vary. As long as idle and WOT engine speed is
set in given range, variance would be ignorable.