XY Powersports XY500UTV, Service Manual

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6. ENGINE REMOVAL; INSPECTION & INSTALLATION
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Valve Spring
● Valve Spring keeps valve and valve seat tight.
Weakened spring results in reduced engine power
output and chattering noise from valve mechanism.
● Measure the spring free length.
Spring free length out of range: → Replace
Service Limit: 38.8mm
Tool : Vernier Caliper.
● Measure the force to compress the spring to the
specified length.
Valve spring tension out of range: → Replace
Service Limit: (IN/EX)
182N-210N/31.5mm
Tool: Spring Scale.
● Measure valve spring incline.
Spring incline out of range: → Replace
Valve Spring Incline Limit: 2.5º/1.7mm
Assembly of Cylinder Head
● Install each valve spring seat;
● Apply moly oil to valve stem seal and fit into
position.
Material: Moly oil
●
Insert the valves, with stems coated with moly oil all
around.
Note: Do not reuse the valve stem seal.
Note: When inserting the valve, be careful
not to damage the lip of the stem seal.
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