PIAGGIO 633929(IT) Service Station Manual page 135

MP3 125
Engine
CAUTION
TO AVOID SCORING THE FAYING SURFACE,
DO NOT KEEP ROTATING THE VALVE WHEN
NO LAPPING COMPOUND IS LEFT. CAREFUL-
LY WASH THE CYLINDER HEAD AND THE
VALVES WITH A SUITABLE PRODUCT FOR
THE TYPE OF LAPPING COMPOUND BEING
USED.
N.B.
DO NOT CHANGE THE POSITIONS THE
VALVES ARE FITTED IN
Characteristic
Valve check standard length
Outlet: 94.4 mm
Valve check standard length
Inlet: 94.6 mm
Valve check Maximum admissible clearance
Outlet: 0.072 mm
Valve check Maximum admissible clearance
Inlet: 0.062 mm
Valve check standard clearance
Outlet: 0.025 ÷ 0.052 mm
Valve check standard clearance
Inlet: 0.013 ÷ 0.040 mm
Valve check Minimum admissible diameter
Outlet: 4.95 mm
Valve check Minimum admissible diameter
Inlet: 4.96 mm
Valve check Standard diameter:
Inlet: 4.972 ÷ 4.987 mm
Valve check Standard diameter:
Outlet: 4.96 ÷ 4.975 mm
ENG - 41