Engine Overhaul; Carburateur - Yamaha QT50 Service Manual

CHAPTER 3.
ENGINE OVERHAUL
3-1 . REMOVAL ............................................ 3-1
A. Preparation for Removal ............. 3-1
B. Exhaust .......................................... 3- 1
C. Carburetor ..................................... 3-1
D. Removal. ........................................ 3-3
3-2 . DISASSEMBLY ................................... 3-3
A.
Reed Valve Assembly .................. 3-3
B. Main Stand .................................... 3-4
C. Kick Crank (Kick Starter) ............. 3-4
D. Drive Shaft (Rear Arm Comp.) ... 3-4
E. Magneto ........................................ 3-4
F. Cylinder Head and Cylinder ........ 3-5
G. Piston Pin and Piston ................... 3-6
H. Crankcase Cover. Right.. ............. 3-6
I. Clutch Assembly and Primary
Drive Gear ..................................... 3-6
J .
Kick Shaft Assembly, Drive Gear
and Kick Pinion Gear ................... 3-7
K. Transmission ................................. 3-8
L. Crankcase ...................................... 3-9
M. Crankshaft ..................................... 3-9
3-3. INSPECTION AND REPA IR ............ 3-10
A. Cylinder Head ............................. 3-10
B. Cylinder ........................................ 3- 10
C. Piston Pin and Bearing .............. 3 - 11
D. Piston ........................................... 3-12
E. Piston Rings ................................ 3-12
F. Autolube Pump ............................ 3-13
G. Clutch ........................................... 3-14
H. Kick Starter ................................. 3- 15
I. Transmission ............................... 3- 15
J .
Crankshaft ................................... 3- 16
K. Bearing and Oil Seals ................ 3- 17
L. Crankcase .................................... 3- 17
CHAPITRE 3.
REVISION GEN ERALE
D U MOTEUR
3- 1. DEPOSE ................................................ .3- 1
A. Preparation pour la Depose ........... .3- 1
B. Echappement .................................. .3- I
C. Carburateur .................................... .3- I
D. Dcpose ............................................. .3-3
3-2. DEMONTAGE ........ ................ ............ .3-3
A. Ensemble Clapets Flexibles ............ 3-3
B. Bequille Centrale ............................. .3-4
C.
Pedale de Kick (K ick Starter) ......... 3-4
D. Arhre de Transmissio n
(Bras Arriere Co mp.) ...................... 3-4
E. Magneto ........................................... 3-4
F. Culasse et Cylindre .......................... 3-5
G. Axe de Piston et Piston ................... 3-6
H. Couvcrcle de Carter Droit .............. 3-6
I.
Ensemble Em bray age et Pignon de
Transmission Primaire .................... 3-6
IJ
J. Ensemble Axe de Kick. Pignon de
Transmission et Pignon de Kick ..... 3-7
K. T ransmission .................................... 3-8
L. Carter ............................................... 3-9
M. Vilebrequin ....................................... 3-9
3-3. JNSPECTION ET REPARATION .. 3-
JO
A. Culasse ........................................... 3- 10
B. Cylindre .......................................... 3- 10
C. Axe
de Piston et Roulement.. ........ 3- 11
D. Piston .............................................. 3- 12
E. Segments ........................................ 3- 12
F. Pompe Autolube ............................ 3- 13
G. Em bray age ..................................... 3-
J
4
H. Kick Starter .................................... 3- 15
I. Transmission .................................. 3- 15
J. Vilebrequin ..................................... 3- 16
K. Roulement et Bagues
d'Etancheite ................................... 3- 17
L. Carter ............................................. 3- 17