Polaris 850 PRO-RMK 155 2.6" QD 2021, Manual

Page: 273 / 747

3
9850060 R02 - 2020-2021 850 AXYS™ Long Track Snowmobile Service Manual
© Copyright Polaris Inc.
3.73
ENGINE DISASSEMBLY / INSPECTION -
TOP END
GENERAL INFORMATION - TOP END
NOTICE
The Cylinder Head, Cylinder, and Pistons may be
serviced with the engine in the chassis.
For image clarity, the images shown in the Engine
Disassembly / Inspection - Top End section are shown
with the engine removed from the chassis.
The following components will need to be removed or
disconnected if the Cylinder Head, Cylinder, and/or
Pistons will be serviced with the engine in the chassis:
• Side panels and hood
• Resonator and tuned pipe
• Oil level sensor from main harness and oil tank
• Air intake tube assembly
• Intake plenum
• Fuel injector harness from main harness
• Steering post
• Exhaust manifold
• High tension wires and spark plugs
• DET and coolant temp. sensor from main harness
• Drain coolant
• Outlet cooling hose
Refer to the applicable sections of the service manual for
removal procedures.
IMPORTANT
Use Digital Wrench to reset the oil pump enrichment
mode timer if the piston(s), cylinder(s), or crankshaft
are serviced / replaced.
CAUTION
Always allow the engine to cool before servicing the
vehicle.
CYLINDER HEAD REMOVAL
1. Remove the E-VES valve assembly. See E-VES-II
Removal page .
2. Slide the springband clamp
q
down the throttle body
coolant hose and remove the coolant hose from the
cylinder head.
3. Loosen all, then remove all cylinder head fasteners.
NOTICE
Clean the fastener threads to remove any thread
locking residue.
ENGINE / COOLING / EXHAUST