2010 YAMAHA WR 450F starter

2-8
MAINTENANCE SPECIFICATIONS
Carburetor: USA, CDN, AUS,
NZ, ZAEUROPE
I. D. mark 5TJE E0 5TJL L0 ----
Main jet (M.J) #162 #160 ----
Main air jet (M.A.J) ø2.0←----
Jet needle (J.N) NFNT NNHU ----
Cutaway (C.A) 1.5←----
Pilot jet (P.J) #45 #48 ----
Pilot air jet (P.A.J) #70←----
Pilot outlet (P.O) ø0.9←----
Bypass (B.P) ø1.0←----
Valve seat size (V.S) ø3.8←----
Starter jet (G.S) #65←----
Leak jet (Acc.P) #60←----
Float height (F.H) 8 mm (0.31 in)←----
Engine idle speed 1,750–1,950 r/min←----
Intake vacuum 34.8–40.1 kPa
(261–301 mmHg,
10.28–11.85 inHg)←----
Hot starter lever free play 3–6 mm (0.12–0.24
in)←----
Lubrication system:
Oil filter type Paper type ----
Oil pump type Trochoid type ----
Tip clearance 0.12 mm or less (0.0047 in or less) 0.20 mm (0.008
in)
Side clearance 0.09–0.17 mm (0.0035–0.0067 in) 0.24 mm (0.009
in)
Housing and rotor clearance 0.03–0.10 mm (0.0012–0.0039 in) 0.17 mm
(0.0067 in)
Bypass valve setting pressure 40–80 kPa (0.4–0.8 kg/cm
2, 5.69–11.38
psi)----
Cooling:
Radiator core size
Width 120.2 mm (4.73 in) ----
Height (Left/Right) 260 mm (10.24 in)/240 mm (9.45 in) ----
Thickness 22 mm (0.87 in) ----
Radiator cap opening pressure 110 kPa (1.1 kg/cm
2, 15.6 psi) ----
Radiator capacity (total) 0.57 L (0.50 Imp qt, 0.60 US qt) ----
Water pump
Type Single-suction centrifugal pump ----Item Standard Limit

2-11
MAINTENANCE SPECIFICATIONS
Charging system:
System type AC magneto ----
Model (stator)/manufacturer 5TJ 50/YAMAHA ----
Normal output 14 V/120 W at 5,000 r/min ----
Charging coil resistance (color) 0.288–0.432 Ω at 20 °C (68 °F) (White–Ground) ----
Lighting coil resistance (color) 0.224–0.336 Ω at 20 °C (68 °F) (Yellow–Ground) ----
Rectifier/regulator:
Regulator type Semiconductor short circuit ----
Model/manufacturer SH770AA/SHINDENGEN ----
Regulated voltage (AC) 12.5–13.5 V ----
Regulated voltage (DC) 14.0–15.0 V ----
Rectifier capacity (AC) 12 A ----
Rectifier capacity (DC) 8 A ----
Electric starting system:
Type Constant mesh ----
Starter motor:
Model/manufacturer 5UM20/YAMAHA ----
Operation voltage 12 V ----
Output 0.48 kW ----
Armature coil resistance 0.0117–0.0143 Ω at 20 °C (68 °F) ----
Brush overall length 7 mm (0.28 in) 3.5 mm (0.14
in)
Brush quantity 2 pcs. ----
Spring force 3.92–5.88 N (400–600 g, 14.1–21.2 oz) ----
Commutator diameter 17.6 mm (0.69 in) 16.6 mm (0.65
in)
Mica undercut (depth) 1.5 mm (0.06 in) ----
Starter relay:
Model/manufacturerRC19-042/MITSUBA ----
Amperage rating 180 A ----
Coil winding resistance 4.2–4.6 Ω at 20 °C (68 °F) ----
Starting circuit cut-off relay:
Model/manufacturer ACM33221 M38/MATSUSHITA ----
Coil winding resistance 75.69–92.51 Ω at 20 °C (68 °F) ----
Fuse (amperage×quantity):
Main fuse 10 A × 1 ----
Reserve fuse 10 A × 1 ----Item Standard Limit

2-12
TIGHTENING TORQUES
TIGHTENING TORQUES
ENGINE
△- marked portion shall be checked for torque tightening after break-in or before each race.
*1: Tighten the cylinder head bolts to 30 Nm (3.0 m•kg, 22 ft•lb) in the proper tightening sequence, remove and retighten
the cylinder head bolts to 20 Nm (2.0 m•kg, 14 ft•lb) in the proper tightening sequence, and then tighten the cylinder head
bolts further to reach the specified angle 180° in the proper tightening sequence.
Part to be tightened Thread size Q'tyTightening torque
Nm m•kg ft•lb
Spark plug M10S × 1.0 1 13 1.3 9.4
Camshaft cap M6 × 1.0 10 10 1.0 7.2
Cylinder head blind plug screw M12 × 1.0 1 28 2.8 20
Cylinder head (stud bolt) M8 × 1.25 1 15 1.5 11
Cylinder head (bolt) M10 × 1.25 4 Refer to TIP.*1
Cylinder head (bolt) M6 × 1.0 2 10 1.0 7.2
Cylinder head cover M6 × 1.0 2 10 1.0 7.2
Cylinder M6 × 1.0 1 10 1.0 7.2
Timing chain tensioner M6 × 1.0 2 10 1.0 7.2
Timing chain tensioner cap bolt M6 × 1.0 1 7 0.7 5.1
Timing chain guide (intake side) M6 × 1.0 2 10 1.0 7.2
Exhaust pipe (nut) M8 × 1.25 1 20 2.0 14
Exhaust pipe (bolt) M8 × 1.25 1 20 2.0 14
△Silencer M8 × 1.25 2 30 3.0 22
Silencer clamp M8 × 1.25 1 16 1.6 11
Exhaust pipe protector M6 × 1.0 3 10 1.0 7.2
Spark arrester M5 × 0.8 4 7 0.7 5.1
Silencer cap M5 × 0.8 6 5 0.5 3.6
Air induction pipe M6 × 1.0 2 10 1.0 7.2
Air cut-off valve assembly and bracket M6 × 1.0 2 10 1.0 7.2
Bracket (air cut-off valve) and frame M6 × 1.0 2 7 0.7 5.1
Carburetor joint M6 × 1.0 3 10 1.0 7.2
Carburetor joint clamp M4 × 0.7 1 3 0.3 2.2
△Air filter case M6 × 1.0 2 8 0.8 5.8
Air filter joint clamp M6 × 1.0 1 3 0.3 2.2
Air filter joint and air filter case M5 × 0.8 1 4 0.4 2.9
Throttle cable adjust bolt and locknut M6 × 0.75 1 4 0.4 2.9
Throttle cable (pull) M6 × 1.0 1 4 0.4 2.9
Throttle cable (return) M12 × 1.0 1 11 1.1 8.0
Throttle cable cover M5 × 0.8 2 4 0.4 2.9
Hot starter plunger M12 × 1.0 1 2 0.2 1.4
Hot starter cable adjust bolt and locknut M6 × 0.75 1 4 0.4 2.9
Air filter element M6 × 1.0 1 2 0.2 1.4
Radiator stay M6 × 1.0 6 7 0.7 5.1
Radiator M6 × 1.0 4 10 1.0 7.2
Radiator hose clamp M6 × 1.0 8 2 0.2 1.4

2-13
TIGHTENING TORQUES
Radiator pipe 1, 2 M10 × 1.0 2 10 1.0 7.2
Impeller M8 × 1.25 1 14 1.4 10
Water pump housing cover M6 × 1.0 3 10 1.0 7.2
Coolant drain bolt M6 × 1.0 1 10 1.0 7.2
Oil pump cover M4 × 0.7 1 2 0.2 1.4
Oil pump M6 × 1.0 2 10 1.0 7.2
Oil pump drive gear shaft M6 × 1.0 1 10 1.0 7.2
Engine oil drain bolt (oil filter) M6 × 1.0 1 10 1.0 7.2
Oil filter cover M6 × 1.0 2 10 1.0 7.2
Oil check bolt (cylinder head) M6 × 1.0 1 10 1.0 7.2
△Oil hose clamp — 2 2 0.2 1.4
Crankshaft end accessing screw M27 × 1.5 1 10 1.0 7.2
Timing mark accessing screw M14 × 1.5 1 6 0.6 4.3
Clutch cover M6 × 1.0 7 10 1.0 7.2
Crankcase cover (right) M6 × 1.0 8 10 1.0 7.2
Crankcase cover (right) M6 × 1.0 2 12 1.2 8.7
Crankcase cover (left) M6 × 1.0 8 10 1.0 7.2
Idle gear cover (starter motor) M6 × 1.0 2 10 1.0 7.2
Crankcase M6 × 1.0 12 12 1.2 8.7
Clutch cable holder M6 × 1.0 1 10 1.0 7.2
Oil drain bolt (crankcase right) M6 × 1.25 1 20 2.0 14
Oil drain bolt (crankcase left) M6 × 1.0 1 20 2.0 14
Oil check bolt (crankcase) M6 × 1.0 1 10 1.0 7.2
Oil strainer M6 × 1.0 1 10 1.0 7.2
Crankcase bearing stopper M6 × 1.0 4 14 1.4 10
Crankcase bearing stopper M6 × 1.0 8 10 1.0 7.2
Drive axle oil seal stopper M6 × 1.0 2 10 1.0 7.2
Ratchet wheel guide M6 × 1.0 2 12 1.2 8.7
Kickstarter crank M8 × 1.25 1 33 3.3 24
Screw (kickstarter crank) M6 × 1.0 1 7 0.7 5.1
Starter clutch M6 × 1.0 6 16 1.6 11
Primary drive gear M20 × 1.0 1 110 11.0 80
Clutch boss M20 × 1.0 1 75 7.5 54
Clutch cable adjust bolt and locknut M8 × 1.0 1 4 0.4 2.9
Clutch spring M6 × 1.0 6 10 1.0 7.2
Balancer M10 × 1.0 1 45 4.5 32
Balancer driven gear M14 × 1.0 1 50 5.0 36
Balancer weight plate M6 × 1.0 3 10 1.0 7.2
Drive sprocket M20 × 1.0 1 75 7.5 54
Drive chain sprocket cover M6 × 1.0 2 7 0.7 5.1
Shift pedal M6 × 1.0 1 12 1.2 8.7
Shift guide M6 × 1.0 2 10 1.0 7.2
Stopper lever M6 × 1.0 1 10 1.0 7.2
Segment M8 × 1.25 1 30 3.0 22Part to be tightened Thread size Q'tyTightening torque
Nm m•kg ft•lb

2-14
TIGHTENING TORQUES
CHASSIS
△- marked portion shall be checked for torque tightening after break-in or before each race.
Part to be tightened Thread size Q'tyTightening torque
Nm m•kg ft•lb
△Upper bracket and outer tube M8 × 1.25 4 21 2.1 15
△Lower bracket and outer tube M8 × 1.25 4 21 2.1 15
△Upper bracket and steering stem M24 × 1.0 1 145 14.5 105
△Handlebar holder (upper) M8 × 1.25 4 28 2.8 20
△Handlebar holder (lower) M12 × 1.25 2 34 3.4 24
△Steering ring nut M28 × 1.0 1 Refer to TIP.
Front fork and cap bolt M51 × 1.5 2 30 3.0 22
Front fork and base valve M30 × 1.0 2 55 5.5 40
Cap bolt and damper rod (front fork) M12 × 1.25 2 29 2.9 21
Bleed screw (front fork) and cap bolt M5 × 0.8 2 1 0.1 0.7
△Front fork and protector M6 × 1.0 6 7 0.7 5.1
△Front fork protector and brake hose holder M6 × 1.0 2 7 0.7 5.1
Throttle cable cap M5 × 0.8 2 4 0.4 2.9
Clutch lever holder mounting M5 × 0.8 2 4 0.4 2.9
Clutch lever mounting M6 × 1.0 1 4 0.4 2.9
Hot starter lever holder mounting M5 × 0.8 2 4 0.4 2.9
Hot starter lever mounting M5 × 0.8 1 2 0.2 1.4
△Front brake master cylinder and bracket M6 × 1.0 2 9 0.9 6.5
Front brake master cylinder cap M4 × 0.7 2 2 0.2 1.4
Brake lever mounting (bolt) M6 × 1.0 1 6 0.6 4.3
Brake lever mounting (nut) M6 × 1.0 1 6 0.6 4.3
Brake lever position locknut M6 × 1.0 1 5 0.5 3.6
△Hose guide (front brake hose) and hose guide bracket M5 × 0.8 1 4 0.4 2.9
△Hose guide (front brake hose) and under bracket M6 ×1.0 1 4 0.4 2.9
△Front brake hose union bolt (master cylinder) M10 × 1.25 1 30 3.0 22
△Front brake hose union bolt (caliper) M10 × 1.25 1 30 3.0 22
△Front brake caliper and front fork M8 × 1.25 2 23 2.3 17
△Front brake caliper and brake hose holder M6 × 1.0 1 10 1.0 7.2
△Brake caliper (front and rear) and pad pin plug M10 × 1.0 2 3 0.3 2.2
△Brake caliper (front and rear) and pad pin M10 × 1.0 2 18 1.8 13
△Brake caliper (front and rear) and bleed screw M8 × 1.25 2 6 0.6 4.3
△Front wheel axle and nut M16 × 1.5 1 90 9.0 65
△Front wheel axle holder M8 × 1.25 4 21 2.1 15
△Front brake disc and wheel hub M6 × 1.0 6 12 1.2 8.7
△Rear brake disc and wheel hub M6 × 1.0 6 14 1.4 10
△Brake pedal mounting M8 × 1.25 1 26 2.6 19
△Rear brake master cylinder and frame M6 × 1.0 2 10 1.0 7.2
Rear brake master cylinder cap M4 × 0.7 2 2 0.2 1.4
△Rear brake hose union bolt (caliper) M10 × 1.25 1 30 3.0 22
△Rear brake hose union bolt (master cylinder) M10 × 1.25 1 30 3.0 22
△Rear wheel axle and nut M20 × 1.5 1 125 12.5 90

2-16
TIGHTENING TORQUES
1. First, tighten the steering ring nut approximately 38 Nm (3.8 m•kg, 27 ft•lb) by using the steering nut wrench, then loosen
the steering ring nut one turn.
2. Retighten the steering ring nut 7 Nm (0.7 m•kg, 5.1 ft•lb).
ELECTRICAL
Tighten the rotor nut to 65 Nm (6.5 m•kg, 47 ft•lb), loosen and retighten the rotor nut to 65 Nm (6.5 m •kg, 47 ft•lb).
△Headlight mounting (left and right) M6 × 1.0 2 7 0.7 5.1
Taillight mounting — 3 1 0.1 0.7
Taillight lead clamp and rear fender — 3 0.5 0.05 0.36
△Catch tank (upper) M6 × 1.0 1 16 1.6 11
△Catch tank (lower) M6 × 1.0 1 7 0.7 5.1
△Footrest bracket and frame M10 × 1.25 4 55 5.5 40
Sidestand mounting M10 × 1.25 1 25 2.5 18
Front reflector (For CDN) M6 × 1.0 2 4 0.4 2.9
Rear reflector (For CDN) M5 × 0.8 3 2 0.2 1.4Part to be tightened Thread size Q'tyTightening torque
Nm m•kg ft•lb
Part to be tightened Thread size Q'tyTightening torque
Nm m•kg ft•lb
Stator M5 × 0.8 2 7 0.7 5.1
Holder (AC magneto lead) M5× 0.8 2 10 1.0 7.2
Rotor M12 × 1.25 1 Refer to TIP.
Neutral switch M5 × 0.8 2 4 0.4 2.9
Starter motor M6 × 1.0 2 10 1.0 7.2
Starter relay terminal M6 × 1.0 2 4 0.4 2.9
Pickup coil M6 × 1.0 2 10 1.0 7.2

2-21
CABLE ROUTING DIAGRAM
CABLE ROUTING DIAGRAM
1. Fuel tank breather hose
2. Clamp
3. Diode
4. Hot starter cable
5. Throttle position sensor lead
6. Wire harness
7. Hump (frame)
8. Negative battery lead
9. Starter motor lead10. Neutral switch lead
11. AC magneto lead
12. Brake hose
13. Rectifier/regulator lead
14. Carburetor breather hose
15. Carburetor overflow hose
16. Catch tank breather hose
17. Hot starter cable protector
18. Rubber cap

2-22
CABLE ROUTING DIAGRAM
A. Insert the end of the fuel tank
breather hose into the hole in
the steering stem.
B. Fasten the throttle cable, hot
starter cable and rectifier/regula-
tor lead onto the frame. Locate
the clamp under the throttle ca-
ble on the right side of the frame,
and face its ends, as well as the
tie ends, downward.
C. Fasten the diode (at the mark-
ing), throttle cable and hot start-
er cable onto the frame. Locate
the clamp end facing toward the
lower right of the frame and with
the tie end facing downward.
D. Fasten the wire harness, throttle
position sensor lead and clutch
cable onto the frame. Pass the
clamp through the hole in the
stay (air cut-off valve). Locate
the clamp end facing toward the
lower side of the frame and cut
off the tie end.
E. Pass the carburetor breather
hoses, carburetor overflow hose
and catch tank breather hose
between the connecting rod and
cross tube (frame).
F. Pass the neutral switch lead on
the inside of the engine bracket.
G. Fasten the neutral switch lead
and AC magneto lead onto the
frame. Locate the clamp end
facing toward the outside of the
frame and tie end facing toward
the rear of the frame.
H. Fasten the AC magneto lead
and neutral switch lead onto the
frame. Locate the clamp end
facing toward the rear of the
frame and cut off the tie end.
I. Pass the neutral switch lead and
AC magneto lead on the inside
of the wire harness.
J. Fasten the AC magneto lead
and neutral switch lead onto the
frame.
K. Pass the wire harness through
the cable guide.
L. Locate the couplers in the frame
recess.
M. Pass the carburetor breather
hoses, carburetor overflow hose
and catch tank breather hose so
that the hoses do not contact the
rear shock absorber.
N. Secure the coupler by pushing it
into the hole in the headlight
unit.
O. Fasten the throttle position sen-
sor lead and the hot starter ca-
ble.P. Locate the clamp between the
hot starter cable protector and
rubber cap.