Page 121 - Manual Oficina XP 1000 14-16

ENGINE / COOLING SYSTEM

VALVE SEAT RECONDITIONING (1000) 4. Inspect the cut area of the seat:
Valve seat reconditioning should be performed by a * If the contact area is less than 75% of the
technician proficient in cylinder head reconditioning circumference of the seat, rotate the pilot 180° and
techniques. Reconditioning techniques vary, so follow make another light cut.
the instructions provided by the valve reconditioning * If the cutter now contacts the uncut portion of the
equipment manufacturer. Do not grind seats more than seat, check the pilot. Look for burrs, nicks, or runout.
necessary to provide proper seat surface, width, and If the pilot is bent it must be replaced.
contact point on valve face.
* If the contact area of the cutter is in the same place,
the valve guide is distorted from improper
WARNING installation.
Wear eye protection or a face shield during cylinder * If the contact area of the initial cut is greater than 3
head disassembly and reassembly. 75%, continue to cut the seat until all pits are
removed and a new seat surface is evident.
Valve Seat Inspection NOTE
Inspect valve seat in cylinder head for pitting, burnt Remove only the amount of material necessary to
spots, roughness, and uneven surface. If any of the repair the seat surface.
above conditions exist, the valve seat must be
reconditioned. If the valve seat is cracked the cylinder
head must be replaced. 5. To check contact area of the seat on the valve face,
apply a thin coating of Prussian Blue™ paste to the
Valve seat width and point of contact on the valve face is
very important for proper sealing. The valve must contact valve seat. If using an interference angle (46°) apply
the valve seat over the entire circumference of the seat, black permanent marker to the entire valve face q.
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.

6. Insert valve into guide and tap valve lightly into place
a few times.

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.

9926816 R06 - 2014-2016 RZR XP 1000 / XP4 1000 Service Manual 3.43
© Copyright Polaris Industries Inc.