Inspection Of Valve; Inspection Of Valve Guide - TOHATSU MFS 4D Service Manual

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32) Inspection of Valve

1.
Check valve for dent and wear on the face. Replace if
necessary.
Measure valve stem outer diameter a. Replace if it is less
2.
than specified value.
Valve Stem Outer Diameter a : Standard value
Intake Side (IN)
Exhaust Side (EX) : 5.44 mm (0.2142 in)
Functional Limit :
Intake Side (IN)
Exhaust Side (EX) : 5.41 mm (0.2130 in)

33) Inspection of Valve Guide

Before inspecting valve guide, check that valve
stem outer diameter is within functional limit.
Measure valve guide inner diameter a. Replace cylinder
1.
block if it is over specified value.
Valve Guide Inner Diameter a : Standard value
Intake and Exhaust Sides : 5.51 mm (0.2169 in)
Functional Limit :
Intake Side (IN)
Exhaust Side (EX) : 5.57 mm (0.2193 in)
2.
Obtain clearance between valve guide and valve stem by
calculating as described below. Replace cylinder head
and/or valve if the clearance is over specified value.
Clearance between Valve Guide and Valve Stem =
Valve Guide Inner Diameter a - Valve Stem Outer Diameter b :
Intake Side (IN)
Exhaust Side (EX) : 0.045 - 0.072 mm (0.00177 - 0.00283 in)
Functional Limit
Intake Side (IN)
Exhaust Side (EX) : 0.100 mm (0.00394 in)
5-38
: 5.47 mm (0.2154 in)
: 5.45 mm (0.2146 in)
: 5.54 mm (0.2181 in)
: 0.024 - 0.044 mm (0.00079 - 0.00173 in)
: 0.070 mm (0.00276 in)
a
b
a
4st 4/5/6 2020

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