Kymco XCITING 500 - Service Manual > Service information

SCHEMATIC DRAWING

SERVICE INFORMATION

GENERAL INSTRUCTIONS

• The cylinder and piston can be serviced with the engine installed in the frame.
• When installing the cylinder, use a new cylinder gasket and make sure that the dowel pins are correctly installed.
• After disassembly, clean the removed parts and dry them with compressed air before inspection.

SPECIFICATIONS

Unit: mm (in)

TROUBLESHOOTING

• When hard starting or poor performance at low speed occurs, check the crankcase breather for white smoke. If white smoke is found, it means that the piston rings are worn, stuck or broken.

Compression too low or uneven compression

• Worn or damaged cylinder and piston rings
• Worn, stuck or broken piston rings

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 cylinder, piston and piston rings
• Incorrectly installed piston

CYLINDER/PISTON REMOVAL

Remove the cylinder head.

Take the block pin out.

Remove the water hose from the cylinder.

Remove the two cylinder bolts.

Remove the cylinder and gasket.

Remove the dowel pins

Remove the piston pin clip.

Place a clean shop towel in the crankcase to keep the piston pin clip from falling into the crankcase.

Press the piston pin out of the piston and remove the piston.

Spread each piston ring and remove it by lifting up at a point opposite the gap

Do not damage the piston ring by spreading the ends too far.

Clean carbon deposits from the piston ring grooves.

INSPECTION

Piston ring

Inspect the piston rings for movement by rotating the rings. The rings should be able to move in their grooves without catching.

Push the ring until the outer surface of the piston ring is nearly flush with the piston and measure the ring-to-groove clearance.

Service Limits:
  Top: 0.08 mm (0.003 in)
  2nd: 0.065 mm (0.0026 in)

Insert each piston ring into the bottom of the cylinder squarely.

Use the piston head to push each piston ring into the cylinder.

Measure the piston ring end gap.

Service Limit:
  Top: 0.5 mm (0.02 in)
  2nd: 0.65 mm (0.026 in)
  Oil ring: 1 mm (0.04 in)

Piston/Piston pin

Measure the piston O.D. at the point 10 mm from the bottom and 90º to the piston pin hole.

Service Limit: 91.9 mm (3.676 in)

Calculate the cylinder-to-piston clearance (cylinder I.D.)

Measure the piston pin hole. Take the maximum reading to determine the I.D..

Service Limit: 22.04 mm (0.8826 in)

Measure the piston pin O.D. at piston and connecting rod sliding areas.

Service Limit: 21.96 mm (0.8784 in)

Measure the piston-to-piston pin clearance.

Service Limit: 0.002 mm (0.0001 in)

Cylinder

Check the cylinder for warpage with a straight edge and feeler gauge in the directions shown.

Service Limit: 0.05 mm (0.002 in)

Check the cylinder wall for wear or damage.

Measure and record the cylinder I.D. at three levels in an X and Y axis. Take the maximum reading to determine the cylinder wear.

Service Limit: 92.1 mm (3.684 in)

Calculate the piston-to-cylinder clearance.

Take a maximum reading to determine the clearance.

Service Limit: 0.1 mm (0.004 in)

Calculate the taper and out-of-round at three levels in an X and Y axis. Take the maximum reading to determine them.

Service Limit:
  Taper: 0.1 mm (0.004 in)
  Out-of-round: 0. 1 mm (0.004 in)

Measure the connecting rod small end I.D..

Service Limit: 22.06 mm (0.8824 in)

Calculate the connecting rod-to-piston pin clearance.

Service Limit: 0.06 mm (0.002 in)

See also: