Yamaha YQ50 Service Manual page 20

Model
Automatic centrifugal clutch:
Clutch shoe thickness
<Wear limit>
Clutch shoe spring free length
Clutch housing inside diameter
<Wear limit>
Clutch-in revolution
Clutch-stall revolution
V-belt:
Width
<Wear limit>
Transmission:
Main axle runout limit
Drive axle runout limit
Kick starter:
Type
Kick clip tension
Carburetor:
I.D mark
Main jet (M.J)
Main air jet (M.A.J)
Jet needle (J.N)
Needle jet (N.J)
Cutaway (C.A)
Pilot jet (P.J)
Bypass 1 (B.P.1)
Air screw (A.S)
Valve seat size (V.S)
Starter jet (G.S.1)
Engine idle speed
Reed valve:
Valve stopper height
Reed valve clearance
Lubrication system:
Stroke
Bore
MAINTENANCE SPECIFICATIONS
2.0 mm
<1.0 mm>
29.9 mm
107.0 mm
107.4 mm
3.950 ~ 4.450 r.p.m.
6.900 ~ 7.700 r.p.m.
16.5 mm
<15.7 mm>
0.08 mm
0.08 mm
Ratchet type
0.15 ~ 0.25 kg
DELLORTO PHBN 12 HS
#86 (F)(B)(P)(I)(E)
#85 (CHE)
#74 (NL)
ø1.5
A21 - 2/5 (F)(B)(P)(I)(E)
A12 - 3/5 (D)(CHE)
A20 - 3/5 (NL)
210 GA (F)(B)(P)(I)(E)(D)
209 GA (CHE)
208 GA (NL)
3.0
4.0 (CHE)
#36
#34 (CHE)
0.8
1 3/8 ± 1/8 (F)(B)(P)(I)(E)
1 3/4 ± 1/8 (D)
1 5/8 ± 1/8 (NL)
2 ± 1/8 (CHE)
1.2
#45
1600 ~ 2000 rpm
6.0 ~ 6.4 mm
Less than 0.2 mm
Autolube pump
2.62 mm (F)(B)(P)(I)(E)
2.5 mm (D)(NL)(CHE)
0.5 mm
2-5
SPEC
YQ50