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9924871 R03 - 2014 Polaris Sportsman® 570 EFI Service Manual
© Copyright 2013 Polaris Sales Inc.
Combustion Chamber Cleaning
WARNING
Wear eye protection during combustion chamber
cleaning.
1. Clean all accumulated carbon deposits from
combustion chambers and valve seat area (1).
NOTE: 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 the areas around spark plug and
valve seats.
Valve Seat Reconditioning
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 the seat is uneven, compression leakage will
result. If the seat is too wide, seat pressure is reduced,
causing carbon accumulation and possible compression
loss. If the seat is too narrow, heat transfer from valve to
seat is reduced. The valve may overheat and warp,
resulting in burnt valves.
ENGINE
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