ENGINE
8-6
EAM30601
ROAD CONDITION AND EXAMPLES OF CARBURETOR SETTING
TIP
Optimum pilot air screw setting can be obtained by adding the ex-factory number of the same screw
back-out turns to any required value provided in the chart. For example, if the ex-factory number is “1”,
add “1” to the value chosen in the chart.
EAM30602
EXAMPLES OF CARBURETOR SETTING DEPENDING ON SYMPTOM
General condition
Sandy condition
Under 10
C
(50
F)
(Winter)
15–25
C
(59–77
F)
(Spring,
Autumn)
Over 25
C
(77
F)
(Summer)
Under 10
C
(50
F)
(Winter)
15–25
C
(59–77
F)
(Spring,
Autumn)
Over 25
C
(77
F)
(Summer)
Main jet
#178
#178
#178
#182
#180
#178
Jet needle
N3CW-3
N3EW-2
N3EJ-2
N3CW-3
N3CW-3
N3CW-3
N3EW-3
N3CW-3
N3EW-2
N3CW-4
N3EW-3
N3EW-3
Pilot jet
#50
#50
#50
#52
#52
#52
Pilot air screw
-1/4
0
0
0
0
+1/4
Power jet
#50
#50
#50
#50
#50
#50
Symptom
Setting
Checking
•
At full throttle
Stall at high speeds
*Hard breathing
Shearing noise
Whitish spark plug
Lean mixture
Increase main jet calibration no.
(Gradually)
•
Discoloration of spark plug
If tan color, it is in good condition.
•
If cannot be corrected:
Clogged float valve seat
Clogged fuel hose
Clogged fuel cock
•
At full throttle
Speed pick-up stops
Slow speed pick-up
Slow response
Sooty spark plug
Rich mixture
Decrease main jet calibration no.
(Gradually)
*In case of racing slight enrichment of
mixture reduces engine trouble.
•
Discoloration of spark plug
If tan color, it is in good condition.
•
If cannot be corrected:
Clogged air filter
Fuel overflow from carburetor
Содержание YZ250 2021
Страница 5: ...EAM20162 YAMAHA MOTOR CORPORATION U S A YZ MOTORCYCLE LIMITED WARRANTY ...
Страница 6: ......
Страница 8: ......
Страница 10: ...MOTORCYCLE CARE AND STORAGE 1 16 CARE 1 16 STORAGE 1 17 ...
Страница 42: ...TIGHTENING TORQUES 2 13 ...
Страница 70: ...CHASSIS 3 26 ...
Страница 106: ...CHAIN DRIVE 4 34 ...
Страница 112: ...CLUTCH 5 5 ...
Страница 113: ...1 2 3 4 5 6 7 8 9 10 ELECTRICAL SYSTEM WIRING DIAGRAM 6 1 COLOR CODE 6 1 ...
Страница 128: ...TROUBLESHOOTING 7 13 ...
Страница 146: ...CHASSIS 8 17 ...