Liangzi Power UTV1000-3, Maintenance Manual

Page: 63 / 184

3.ENGINE
3- 35
Valve Stem Seal
Always install NEW seals whenever valves are
removed.
Valve
Inspect valve surface, check for abnormal stem
wear and bending. If out of specification, replace
by a new one.
VALVE OUT OF ROUND
(INTAKE AND EXHAUST VALVES)
NEW 0.005mm(.0002 in)
SERVICE LIMIT 0.06 mm(.0024in)
Valve Stem
Measure valve stem in three places using a
micrometer .
Replace valve if valve stem is out of specification
or has other damages such as wear or friction
surface.
A. Valve stem diameter
VALVE STEM DIAMETER
EXHAUST VALVE
NEW 4.956mm to4.970 mm
(.1951 in to.1957in)
SERVICE LIMIT 4.930mm(.1941 in)
INTAKE VALVE
NEW 4.966mm to4.980 mm
(.1955in to.1961 in)
SERVICE LIMIT 4.930mm(.1941 in)
Valve Face and Seat
1. Valve seat
2. Exhaust valve contaminated area
3. Valve face (contact surface to valve seat)
Check valve face and seat for burning or pittings
and replace valve or cylinder head if there are
signs of damage.
Ensure to seat valves properly. Apply some lapping
compound to valve face and work valve on 1ts seat
with a lapping tool (see VALVE GUIDES in this
subsection).
Measure valve face contact width.
NOTE: The location of contact area should be in
center of valve seat.
Measure valve seat width using a caliper .
VALVE SEAT CONTACT WIDTH
EXHAUST VALVE
NEW 1.25mm to1.55mm
(.049in to.061 in)
SERVICE LIMIT 2.00 mm(.079 in)
INTAKE VALVE
NEW 1.05mm to1.35mm
(.041 in to.053in)
SERVICE LIMIT 1.80mm(.071 in)