Yamaha YZ125(D) Owner's Service Manual page 72

d. Measure the fuel level with the
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.
Reed valve bending limit
"a":
0.2 mm (0.008 in)
CARBURETOR AND REED VALVE
2. Measure:
• Valve stopper height "a"
Out of specification → Adjust
stopper/Replace valve stopper.
Valve stopper height "a":
8.2–8.6 mm (0.323–
0.339 in)
INSTALLING THE REED VALVE
1. Install:
• Reed valve "1"
• Stopper (reed valve) "2"
• Screw (reed valve) "3"
Screw (reed valve):
1 Nm (0.1 m•kg, 0.7
ft•lb)
• 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"
Bolt (carburetor joint):
10 Nm (1.0 m•kg, 7.2
ft•lb)
4-10
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.
Pilot air screw:
2-1/4 turns out
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"