3
9850067 R01 - 2020-2021 GENERAL / GENERAL XP Service Manual
© Copyright Polaris Inc.
3.5
No engine will have a perfect seal with 0 percent loss. A
leakdown reading of less than 10 percent loss indicates
the engine is in good condition. When performing the test
monitor where the leakage is occurring. At 20 percent,
suspect an internal issue, and an overhaul is likely.
Common leak areas:
• Cylinder Head Gasket
• Piston / Piston Rings / Cylinder Wall
• Intake Valve(s)
• Exhaust Valve(s)
• Valve Seat(s)
Pay close attention during testing air that can be heard or
felt is the best indication of where the leak is originating.
Symptom Cause
Air can be heard / felt
through the intake or
exhaust
Suspect a valve sealing
issue
Air can be heard / felt
through the oil fillcap or
dipstick area
Air is escaping past piston
and / or rings. Inspect ring
lands, rings, piston and
cylinder
Bubbles seen / heard in
the cooling system
This indicates that the
cooling system is
pressurizing, suspect a
cylinder head or head
gasket issue
ENGINE / COOLING SYSTEM