Valve Seat Reconditioning; Combustion Chamber - Polaris SPORTSMAN 400 2003 Service Manual

Valve Guide I.D.:
.2362-.2367I (6.0-6.012 mm)
6. Measure valve guide inside diameter at the top
middle and end of the guide using a small hole
gauge and a micrometer.
directions, front to back and side to side.
7. Subtract valve stem measurement to obtain stem
to guide clearance. NOTE: Be sure to measure
each guide and valve combination individually.
8. Replace valve and/or guide if clearance is
excessive. Compare to specifications.
NOTE: If valve guides are replaced, valve seats must
be reconditioned. Refer to Valve Seat Reconditioning
for procedure.

COMBUSTION CHAMBER

Clean all accumulated carbon deposits from
combustion chamber and valve seat area with a soft
wire brush.
VALVE SEAT
RECONDITIONING
Valve Seat Inspection
Inspect valve seat in cylinder head for pitting, burnt
spots, roughness, and uneven surface. If any of the
above conditions exist, the valve seat must be
reconditioned. See Valve Seat Reconditioning, Page
3.25. If the valve seat is cracked the cylinder head
must be replaced.
Cylinder Head Reconditioning
NOTE: Servicing the valve guides and valve seats
requires special tools and a thorough knowledge of
reconditioning techniques. Follow the instructions
provided in the cylinder head service tool kit.
CAUTION: Wear eye protection when performing
cylinder head service. Valve guide replacement will
Measure in two
require heating of the cylinder head. Wear gloves to
prevent burns.
Valve Guide Removal/Installation
1. Remove all carbon deposits from the combustion
2. Place new valve guides in a freezer for at least 15
3. Heat cylinder head in an oven or use a hot plate to
VALVE SEAT
RECONDITIONING, CONT.
Follow the manufacturers instructions provided with
the
Reconditioning Kit (PN 2200634). Abrasive stone
seat reconditioning equipment can also be used.
Keep all valves in order with their respective seat.
chamber, valve seat and valve guide area before
attempting to remove valve guides. CAUTION:
Carbon deposits are extremely abrasive and may
damage the valve guide bore when guides are
removed.
minutes while heating cylinder head.
bring cylinder head temperature to 212° F (100°
C). CAUTION: Do not use a torch to heat
cylinder head or warpage may result from uneven
heating. Head temperature can be checked with
a pyrometer or a welding temperature stick.
valve seat cutters
ENGINE
in the Valve Seat
3.23