KYMCO ADG5, Manual

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4. Engine XCITING 400i/XCITING S 400
Compression too high
• Excessive carbon build-up in combustion chamber
Abnormal noise
• Incorrect valve clearance adjustment
• Sticking valve or broken valve spring
• Damaged or worn camshaft
• Worn cam chain tensioner
• Worn camshaft and rocker arm
White smoke from exhaust muffler
• Worn valve stem or valve guide
• Damaged valve stem oil seal
Cylinder and Piston
• The cylinder and piston cannot be serviced with the engine installed in the frame.
• After disassembly, clean the removed parts and dry them with compressed air before
inspection.
• If replacing the piston or cylinder, they must be changed as a pair.
TROUBLESHOOTING
Compression too low or uneven compression
• Worn, stuck or broken piston rings
• Worn or damaged cylinder and piston
Compression too high
• Excessive carbon build-up in combustion chamber or on piston head.
Excessive smoke from exhaust muffler
• Worn or damaged piston rings
• Worn or damaged cylinder and piston
Abnormal noisy piston
• Worn cylinder, piston and piston rings
• Worn piston pin hole and piston pin
4‐3