Carburettor Adjustment Procedure; General Adjusting Rules; Presetting Idle Adjust Screw, L Mixture Needle And H Mixture Needle - Echo CS-500ES Service Data

CS-500ES

2 CARBURETTOR ADJUSTMENT PROCEDURE

2-1 General adjusting rules

A. Before adjustment, check the following items.
1. The correct spark plug must be clean and properly gapped.
2. The air fi lter element must be clean and properly installed.
3. The muffl er exhaust port must be clear of carbon.
4. The fuel lines, tank vent and fuel fi lter are in good condition and clear of debris.
5. The fuel is fresh ( > 89 octane : RON ) and properly mixed at 50 : 1 with "ISO L-EGD" or "JASO FC/
FD" 2-stroke oil.
6. The recommended bar and chain must be installed, and properly tensioned.
NOTE : In order to achieve proper carburettor adjustment, a 38, 45 or 50 cm bar and chain combination
should be installed on the unit, otherwise serious engine damage will occur due to overspeeding.
B. Preliminary adjustment. Adjustment by Idle adjust screw of carburettor.
Start and run engine for 100 seconds alternating engine speed between WOT and idle every 5 seconds.
Adjust idle adjust screw to 3,200 +/- 200 r/min. Make sure WOT engine speed in range 11,800 - 12,500
r/min. If engine does not run correctly after this adjustment, proceed to the next step 2-2.

2-2 Presetting Idle adjust screw, L mixture needle and H mixture needle

(D)
SERVICE INFORMATION
(C)
(B)
(A)
Tools Required: Small screwdriver with 2.5 mm
blade, P/N G310-000050 electronic tachometer,
P/N Y089-000090 D-Shaped tool (A).
1. Turn L and H mixture needles clockwise until
lightly seated, and then turn out both mixture nee-
dles following turns:
L mixture needle (B) : 1 1/2,
H mixture needle (C) : 3 1/8
NOTE: If needles are overtighted during seating,
damage to carburettor may occur.
2. Remove air cleaner lid and air fi lter to expose
the Idle adjust screw and throttle plate. Turn Idle
adjust screw (D) anticlockwise until Idle adjust
screw tip just touches throttle plate. Then turn Idle
adjust screw (D) 2 turns clockwise. Reinstall air fi l-
ter, and cleaner lid.
NOTE : The initial carburettor settings for Idle
adjust screw, L and H mixture needles are intended
to start and run the engine before fi nal carburettor
adjustments are made through this procedure.
The actual number of turns needed for engine
operation may vary.
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