Valve Mechanism; Valve And Valve Guide - Mazda 121 Workshop Manual

INSPECTION / REPAIR
4..
fJ
-sreure
THICKNESS
4. l\4easure the manifold contact surface distortion in the six
directions shown in the figure.
oistorllon: 0.t5mm (0.006 in) max.
5. lf distortion exceeds specification, grind the surface or re-
olace the cvlinder head.
VALVE MECHANISM
Valve and Valve Gulde
1. Inspect each valve for the following. Replace or resurlace
the valve il necessary.
(1) Damaged or bent stem
(2) Rough or damaged face
(3) Darnaged or unevenly worn stem tip
2. Measure the valve head margin lhickness 01 each valve.
Replace the valve if necessary.
Margin thicknesa min.
B3
IN
1.1 (0.043)
EX
1.2 (O.O47)
3. Measure the length of each valve.
Length
mm {in)
diameter of each valve al the points
4. Measure the stem
Dlameter
B3
IN
5.970-5_985 i0.2350-0.2356)
EX
5.965-5.980 {0.2348-0.23541
5. Measure the inner diameter of each valve guide at the points
shown.
lnner diameter
B3
IN, EX
6.01-6.03 (0.2366-0 2374)
6. Calculate the valve stem to guide clearance-
Subtract the outer diameter of the valve stem from the in-
ner diameter of the corresponding valve guide.
Clearance
lN r 0.025-0.060mm (0.0010--1t.0024 In)
EX: 0.030-0.065mm (0.0012-0.0026 in)
Maximum: 0.20mm (0.008 In)
7. lf the clearance exceeds sp€cification, replace the valve
and/or valve guide.
B-49
B3
IN
Standard
108.24 14.261't
107 .74 14.241
EX
Standa.d
109.34 {4.304)
Minimum
108.84 (4.?85)
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