Yamaha TMAX 2020 Service Manual

5-27
VALVES AND VALVE SPRINGS
a. Apply a coarse lapping compound “a” to the
valve face.
NOTICE
ECA13790
Do not let the lapping compound enter the
gap between the valve stem and the valve
guide.
b. Apply molybdenum disulfide oil onto the
valve stem.
c. Install the valve into the cylinder head.
d. Turn the valve until the valve face and valve
seat are evenly polished, then clean off all
of the lapping compound.
TIP
For the best lapping results, lightly tap the valve
seat while rotating the valve back and forth be-
tween your hands.
e. Apply a fine lapping compound to the valve
face and repeat the above steps.
f. After every lapping procedure, be sure to
clean off all of the lapping compound from
the valve face and valve seat.
g. Apply blue layout fluid “b” onto the valve
face.
h. Install the valve into the cylinder head.
i. Press the valve through the valve guide and
onto the valve seat to make a clear impres-
sion.
j. Measure the valve seat width “c” again. If
the valve seat width is out of specification,
reface and lap the valve seat.
EAS30286
CHECKING THE VALVE SPRINGS
The following procedure applies to all of the
valve springs.
1. Measure:
• Valve spring free length “a”
Out of specification  Replace the valve
spring.
G088968
G088969
Free length (intake)
36.73 mm (1.45 in)
Limit
34.89 mm (1.37 in)
Free length (exhaust)
36.73 mm (1.45 in)
Limit
34.89 mm (1.37 in)
G088967
G088970

Yamaha TMAX 2020 Specifications

General

Displacement	562cc
Bore x Stroke	70.0 mm x 73.0 mm
Compression Ratio	10.9:1
Fuel System	Fuel Injection
Ignition System	TCI
Transmission	V-Belt Automatic
Rear Suspension	Swingarm
Front Brake	Hydraulic dual disc, Ø267 mm
Rear Brake	Hydraulic single disc, Ø282 mm
Front Tyre	120/70R15M/C 56H
Rear Tyre	160/60R15M/C 67H
Overall Length	2, 200 mm
Overall Width	765 mm
Seat Height	800 mm
Wheelbase	1, 575 mm
Wet Weight	218 kg
Fuel Tank Capacity	15 litres
Engine Type	Liquid-cooled, 4-stroke, DOHC, 4-valve
Maximum Torque	55.7 Nm @ 5, 250 rpm
Front Suspension	Telescopic fork
Overall Height	1, 420mm