Page 204 - Manual_Polaris_RZR_ProXP-20-21
P. 204

ENGINE / COOLING SYSTEM


                8. Be sure to measure each guide and valve           VALVE SEAT RECONDITIONING
                   combination individually.
                                                                                           CAUTION
                                     NOTICE
                                                                       The EXHAUST valves are sodium filled and should be
                        The valve guides cannot be replaced.                          handled with care.


                                                                     Valve seat reconditioning should be performed by a
                                                                     technician proficient in cylinder head reconditioning
                COMBUSTION CHAMBER CLEANING                          techniques. Reconditioning techniques vary, so follow
                                                                     the instructions provided by the valve reconditioning
                                      WARNING                        equipment manufacturer. Do not grind seats more than
                   Wear eye protection during combustion chamber     necessary to provide proper seat surface, width, and
                                     cleaning.                       contact point on valve face.

                                                                                           WARNING
                1. Clean all accumulated carbon deposits from
                   combustion chambers q and valve seat area w.         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
                                     NOTICE                          loss. If seat is too narrow, heat transfer from valve to seat
                                                                     is reduced. The valve may overheat and warp, resulting
                 Carbon Clean Fuel Treatment (2871326) can be used
                           to help remove carbon deposits.           in burnt valves.
                   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.







                                                                     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.






                3.60                                                       9930583 R01 - 2020-2021 RZR PRO XP / XP 4 Service Manual
                                                                                                © Copyright Polaris Industries Inc.
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