FUEL SYSTEM
CS-501SX, CS-501SXH
501sx
28
4-6 Adjusting carburetor
4-6-1 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. 40, 45 or 50 cm bar and chain must be installed, and properly tensioned.
7. For CS-501SXH, turn off the heater switch.
B. Preliminary adjustment. Adjustment by Throttle adjust screw of carburetor.
Start and run engine for 100 seconds alternating engine speed between WOT and idle every 5 seconds.
Adjust throttle adjust screw to 2,700 +/- 200 r/min. Make sure WOT engine speed in range 13,000 -
13,800 r/min. If engine does not run correctly after this adjustment, proceed to the next step 2-2.
4-6-2 Initial setting Throttle adjust screw, L mixture needle and H mixture needle
Tools Required: Small fl at head screwdriver with 2.5
mm blade, P/N 897802-33330 tachometer PET-
1000R, P/N Y089-000094 Carburetor adjustment
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 3/4
H mixture needle (C) : 3 5/8
NOTE: If needles are overtighted during seating,
damage to carburetor may occur.
2. Remove air cleaner lid and air fi lter to expose
the Throttle adjust screw and throttle plate. Turn
Throttle adjust screw (D) counterclockwise until
Throttle adjust screw tip just touches throttle plate.
Then turn Throttle adjust screw (D) 2 1/8 turns
clockwise. Reinstall air fi lter, and cleaner lid.
NOTE : The initial carburetor settings for Throttle
adjust screw, L and H mixture needles are intended
to start and run the engine before fi nal carburetor
adjustments are made through this procedure.
The actual number of turns needed for engine
operation may vary.
1
7
4
3
2
(A)
(D)
(B)
(C)
