Valve Sealing Test; Valve Seat Reconditioning (900) - Polaris RANGER XP 900 2018-2019 Service Manual

ENGINE / COOLING / HVAC SYSTEM

VALVE SEALING TEST

1. Clean and dry the combustion chamber area
2. Pour a small amount of clean solvent into each
w
intake port and check for leakage around the
valves. The valve seats should hold fluid with no
seepage.
3. Repeat for exhaust valves by pouring fluid into each
e
exhaust port .
3.40

VALVE SEAT RECONDITIONING (900)

q
. Valve seat reconditioning should be performed by a
technician proficient in cylinder head reconditioning
techniques. Reconditioning techniques vary, so follow
the instructions provided by the valve reconditioning
equipment manufacturer. Do not grind seats more than
necessary to provide proper seat surface, width, and
contact point on valve face.
Wear eye protection or a face shield during cylinder
head disassembly and reassembly.
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. If the valve seat is cracked the cylinder
head must be replaced.
Valve seat width and point of contact on the valve face is
very important for proper sealing. The valve must contact
the valve seat over the entire circumference of the seat,
and the seat must be the proper width all the way
around. If seat is uneven, compression leakage will
result. If seat is too wide, seat pressure is reduced,
causing carbon accumulation and possible compression
loss. If seat is too narrow, heat transfer from valve to seat
is reduced. The valve may overheat and warp, resulting
in burnt valves.
Renewing Valve Seats
1. Install pilot into valve guide.
2. Apply cutting oil to valve seat and cutter.
3. Place 46° cutter on the pilot and make a light cut.
9929399 R01 - 2018-2019 RANGER XP/ CREW 900/1000 Service Manual
CAUTION
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