Polaris RZR PRO XP 2020, Service Manual

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3.60
9850068 R01 - 2020-2021 RZR PRO XP / XP 4 Service Manual
© Copyright Polaris Industries Inc.
8. Be sure to measure each guide and valve
combination individually.
NOTICE
The valve guides cannot be replaced.
COMBUSTION CHAMBER CLEANING
WARNING
Wear eye protection during combustion chamber
cleaning.
1. Clean all accumulated carbon deposits from
combustion chambers
q
and valve seat area
w
.
NOTICE
Carbon Clean Fuel Treatment (2871326) can be used
to help remove carbon deposits.
Do not use a metal scraper, a coarse wire brush or
abrasive cleaners to clean the cylinder head. Damage
may result.
2. Visually inspect cylinder head gasket surface and
combustion chamber for cracks or damage. Pay
close attention to areas around spark plug and valve
seats.
VALVE SEAT RECONDITIONING
CAUTION
The EXHAUST valves are sodium filled and should be
handled with care.
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.
WARNING
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.
ENGINE / COOLING SYSTEM