Checking The Valve Guide - SELVA MARINE Blue Whale 250 EFI Service Manual

Valve margin thickness a:
Intake:
0.50–0.90 mm (0.020–0.035 in)
Exhaust:
0.90–1.30 mm (0.035–0.051 in)
3. Measure the valve stem diameter b.
Replace if out of specification.
Valve stem diameter b:
Intake:
5.477–5.492 mm
(0.2156–0.2162 in)
Exhaust:
5.464–5.479 mm
(0.2151–0.2157 in)
4. Measure the valve stem runout. Replace
if above specification.
6P23H11
Valve stem runout limit:
0.01 mm (0.0004 in)

Checking the valve guide

NOTE:
Before checking the valve guides, make sure
that the valve stem diameter is within specifi-
cation.
1. Measure the valve guide inside diameter
a.
a
Valve guide inside diameter a:
Intake and exhaust:
5.504–5.522 mm
(0.2167–0.2174 in)
2. Calculate the valve stem-to-valve guide
clearance as follows. Replace the valve
guide if out of specification.
Valve stem-to-valve guide clearance
= valve guide inside diameter – valve
stem diameter:
Intake:
0.012–0.045 mm
(0.0005–0.0018 in)
Exhaust:
0.025–0.058 mm
(0.0010–0.0023 in)
Cylinder head
1
2
3
4
S69J5770
5
6
7
8
9
5-44