APRILIA M192M Workshop Manual page 131

Engines M192M / M191M / M245M / M234M / M282M / M281M
Standard clearance
Intake: 0.013 ÷ 0.040 mm
Exhaust: 0.025 ÷ 0.052 mm
Max. allowed clearance
Intake: 0.062 mm
Exhaust: 0.072 mm
•
Check the surface mating the shim joint terminal for
wear.
Valve standard length (L – l)
L (Engines M192M / M245M / M281M / M234M / M282M)
(125 - 200 cc)=Intake: 94.6 mm
L (Engine M191M) (150 cc)=Intake: 80.6 mm
l (Engines M192M / M245M / M281M / M234M / M282M)
(125 - 200 cc)=Exhaust: 94.4 mm
l (Engine M191M) (150 cc)=Exhaust: 79.6 mm
•
If after the above checks all the values are within the
specified limits, use the same valves. To ensure per-
fect sealing, grind valves with fine emery cloth. When
grinding, position the head with the valve axes in hori-
zontal position to prevent emery cloth residues from
entering the valve guide stem coupling (see figure).
WARNING
To avoid scoring the mating surface, do not
overturn valve when the emery cloth is fin-
ished. Thoroughly wash head and valves with a
product suitable to the emery cloth used.
NOTE Do not confuse valve-assembling position.
ENGINE
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