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

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9850060 R02 - 2020-2021 850 AXYS™ Long Track Snowmobile Service Manual
© Copyright Polaris Inc.
• Stage 1: Low-Port: Upper / Lower Valves Closed
Stage 1 valve position is set within seconds of engine
start-up and is active from idle to approximately 6,000
RPM.
• Stage 2: Mid-Port: Upper Valves Closed / Lower
Valves Retracted
Stage 2 valve position is set at approximately 6,000 to
7,200 RPM. At this stage, the upper valves are
establishing the effective exhaust port height for each
cylinder.
• Stage 3: High-Port: (Upper / Lower Valves Fully
Retracted
Stage 3 valve position is set at approximately 7,200
RPM. At this stage, the lower valves engage the steps
in the upper valves and retract the upper valves out of
the exhaust ports.
NOTICE
Exhaust valve stage positions given at approximate
engine RPMs. Actual E-VES position is determined by
current engine RPM, throttle position, barometric
pressure, and diagnostic conditions.
ENGINE / COOLING / EXHAUST