14
Measuring Valve Guide/Valve Stem
Clearance
1. Using a micrometer and small bore gauge, take
diameter readings on the valve stems and inside the
guides.
2. The stem clearance inside the guide must be within
0.0016-0.0020" for the intake and 0.0020-0.0030"
for the exhaust.
NOTE: Be sure to take readings at more than one
place along the length of each stem and guide.
Lapping Valves
NOTE: Ensure that all carbon has been removed
from the valves.
1. Using a valve lapper, produce a contact pattern on
each valve face by applying a uniform coat of valve
lapping compound to the valve seat and by rotating
and tapping the valve head.
2. Acceptable width of valve seat contact width (mea-
surement A) must be at least 0.03".
GEN-0023
GEN-0024
NOTE: Do not grind the valves. If a valve is dam-
aged, it must be replaced.
3. Lubricate each valve stem with lightweight oil; then
apply a small amount of valve lapping compound to
the entire seating face of each valve.
4. Attach the suction cup of a valve lapping tool to the
head of the valve.
5. Rotate the valve until the valve and seat are evenly
polished.
6. Clean all compound residue from the valve and seat.
Valve Springs
1. When the valve springs are weak, the valve and
valve seat fail to form a good seal, thus allowing gas
to leak past the valve seat causing a loss of power.
Whether or not a valve spring is weak can be deter-
mined by its free length.
GM128D
2. Minimum valve spring free length must not exceed
1.04".
NOTE: With the crankshaft at top dead center on
the compression stroke, install the valve springs and
spring retainers; then compress the valve springs and
install the valve keepers.
CAM LOBE WEAR
Worn cam lobes result in reduced power output. The limit
of cam lobe wear is specified for both intake and exhaust
lobes in terms of cam height to be measured with a
micrometer. Replace the camshaft if not within 1.048-
1.052".
GEN0028B
IO088
Summary of Contents for 2018 ZR 200
Page 1: ......
Page 66: ...65 Wiring Diagram 0752 220 ...
Page 67: ...66 NOTES ...
Page 68: ...67 NOTES ...
Page 69: ...68 NOTES ...
Page 70: ......