7-4
ENGINE
ROAD CONDITION AND EXAMPLES OF CARBURETOR SETTING
A. For USA and CDN
B. For EUROPE
C. For AUS, NZ and ZA
SPECIFICATIONS OF JET NEEDLE (For USA and CDN)
SPECIFICATIONS OF JET NEEDLE (For EUROPE, AUS, NZ, and ZA)
EXAMPLES OF CARBURETOR SETTING DEPENDING ON SYMPTOM
General condition
Sandy condition
Under 10°C
(50°F)
15–25°C (59–
77°F)
Over 30°C
(86°F)
Under 10°C
(50°F)
15–25°C (59–
77°F)
Over 30°C
(86°F
(Winter)
(Spring, Au-
tumn)
(Summer)
(Winter)
(Spring, Au-
tumn)
(Summer)
Main jet
A
#420
#410
#410
#440
#430
#430
B, C
#440
#430
#420
#460
#450
#440
Jet needle
A
6BFY43-74-3
6BFY42-74-3
6BFY42-74-3
6BFY43-74-4
6BFY42-74-4
6BFY43-74-3
B, C
6BFY44-74-3
6BFY43-74-3
6BFY44-74-2
6BFY43-74-4
6BFY44-74-3
6BFY43-74-3
Pilot jet
A
#42.5
#40
#40
#42.5
#40
#40
B
#47.5
#45
#42.5
#47.5
#45
#42.5
C
#42.5
#40
#40
#45
#42.5
#40
Pilot air screw
2-1/4
2-1/4
2-1/4
2-1/4
2-1/4
2-1/4
Diameter of straight portion
ø2.72 mm
(0.1071 in)
ø2.73 mm
(0.1075 in)
ø2.74 mm
(0.1079 in)
ø2.75 mm
(0.1083 in)
ø2.76 mm
(0.1087 in)
Rich
1 richer
6BFY44-72-3
6BFY44-73-3
6BFY44-74-3
6BFY44-75-3
6BFY44-76-3
6BFY42-72-4
6BFY42-73-4
6BFY42-74-4
6BFY42-75-4
6BFY42-76-4
0.5 richer
6BFY43-72-3
6BFY43-73-3
6BFY43-74-3
6BFY43-75-3
6BFY43-76-3
STD
6BFY42-72-3
6BFY42-73-3
6BFY42-74-3
6BFY42-75-3
6BFY42-76-3
0.5 leaner
6BFY43-72-2
6BFY43-73-2
6BFY43-74-2
6BFY43-75-2
6BFY43-76-2
1 leaner
6BFY44-72-1
6BFY44-73-1
6BFY44-74-1
6BFY44-75-1
6BFY44-76-1
Lean
6BFY42-72-2
6BFY42-73-2
6BFY42-74-2
6BFY42-75-2
6BFY42-76-2
Diameter of straight portion
ø2.72 mm
(0.1071 in)
ø2.73 mm
(0.1075 in)
ø2.74 mm
(0.1079 in)
ø2.75 mm
(0.1083 in)
ø2.76 mm
(0.1087 in)
Rich
1 richer
6BFY43-72-4
6BFY43-73-4
6BFY43-74-4
6BFY43-75-4
6BFY43-76-4
0.5 richer
6BFY44-72-3
6BFY44-73-3
6BFY44-74-3
6BFY44-75-3
6BFY44-76-3
6BFY42-72-4
6BFY42-73-4
6BFY42-74-4
6BFY42-75-4
6BFY42-76-4
STD
6BFY43-72-3
6BFY43-73-3
6BFY43-74-3
6BFY43-75-3
6BFY43-76-3
0.5 leaner
6BFY44-72-2
6BFY44-73-2
6BFY44-74-2
6BFY44-75-2
6BFY44-76-2
6BFY42-72-3
6BFY42-73-3
6BFY42-74-3
6BFY42-75-3
6BFY42-76-3
Lean
1 leaner
6BFY43-72-2
6BFY43-73-2
6BFY43-74-2
6BFY43-75-2
6BFY43-76-2
Symptom
Setting
Checking
At full throttle
Stall at high speeds
*Hard breathing
Shearing noise
Whitish spark plug
↓
Lean mixture
Increase main jet calibration no. (Gradual-
ly)
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
Summary of Contents for YZ125X1
Page 2: ...1C3 9 33_cover 07 6 14 9 59 AM Page 2...
Page 3: ...YZ125 X X1 1C3 28199 33 E0 2008 OWNER S SERVICE MANUAL...
Page 4: ......
Page 87: ...4 32 WATER PUMP...
Page 131: ...5 30 STEERING 9 Bearing race 2 Refer to removal section Order Part name Q ty Remarks...
Page 159: ......