Yamaha YZ125X1, Owner'S Service Manual

Page: 65 / 160

4-10
CARBURETOR AND REED VALVE
fuel level gauge.
Keep the carburetor and fuel level
gauge vertically when measuring the
fuel level.
e. If the fuel level is not within speci-
fication, inspect the valve seat
and needle valve.
f. If either is worn, replace them
both.
g. If both are fine, adjust the fuel lev-
el by bending the float tab "b" on
the float.
h. Recheck the fuel level.
CHECKING THE FLOAT
1. Inspect:
• Float "1"
Damage
→
Replace.
CHECKING THE REED VALVE
1. Measure:
• Reed valve bending "a"
Out of specification
→
Replace.
2. Measure:
• Valve stopper height "a"
Out of specification
→
Adjust stop-
per/Replace valve stopper.
INSTALLING THE REED VALVE
1. Install:
• Reed valve "1"
• Stopper (reed valve) "2"
• Screw (reed valve) "3"
• Install the reed valve with the reed
valve bending as shown.
• Note the cut "a" in the lower corner
of the reed and stopper plate.
Tighten each screw gradually to
avoid warping.
2. Install:
• Reed valve assembly "1"
• Reed valve spacer "2"
3. Install:
• Carburetor joint "1"
• Bolt (carburetor joint) "2"
ASSEMBLING THE CARBURETOR
1. Install:
• Throttle stop screw "1"
• Locknut "2"
• Pilot air screw "3"
Note the following installation
points:
a. Screw in the pilot air screw until it
is lightly seated.
b. Back out it by the specified num-
ber of turns.
2. Install:
• Starter plunger "1"
3. Install:
• Main jet holder "1"
• Main jet "2"
• Pilot jet "3"
• Valve seat "4"
• Screw (valve seat) "5"
4. Install:
• Needle valve "1"
• Float "2"
• Float pin "3"
• Screw (float pin) "4"
• Needle jet cover "5"
Reed valve bending limit:
0.2 mm (0.008 in)
Valve stopper height:
8.2–8.6 mm (0.323–
0.339 in)
Screw (reed valve):
1 Nm (0.1 m•kg, 0.7
ft•lb)
Bolt (carburetor joint):
10 Nm (1.0 m•kg, 7.2
ft•lb)
Pilot air screw:
2-1/4 turns out