[. . . ] 2008
SERVICE MANUAL
XT660Z
11D-F8197-E0
XT660Z (2008) SERVICE MANUAL © 2008 by Yamaha Motor Italia S. p. A. Any reproduction or unauthorized use without the written permission of Yamaha Motor Italia S. p. A. Printed in Italy
EAS00020
NOTICE
This manual was produced by the Yamaha Motor Italia S. p. A. It is not possible to include all the knowledge of a mechanic in one manual. [. . . ] Measure: · Valve stem runout Out of specification Replace the valve. NOTE: · When installing a new valve, always replace the valve guide. · If the valve is removed or replaced, always replace the valve stem seal. Press the valve through the valve guide and onto the valve seat to make a clear impression. NOTE: Where the valve seat and valve face contacted one another, the blueing will have been removed.
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VALVES AND VALVE SPRINGS
4. Lap: · Valve face · Valve seat NOTE: After replacing the cylinder head or replacing the valve and valve guide, the valve seat and valve face should be lapped.
a. CAUTION: Do not let the lapping compound enter the gap between the valve stem and the valve guide.
e. Apply a fine lapping compound to the valve face and repeat the steps above. After every lapping procedure, be sure to clean off all of the lapping compound from the valve face and valve seat. Apply Mechanic's blueing dye (Dykem) "b" onto the valve face.
b. Press the valve through the valve guide and onto the valve seat to make a clear impression. If the valve seat width is out of specification, reface and lap the valve seat.
EAS00241
c. Turn the valve until the valve face and valve seat are evenly polished, then clean off all of the lapping compound. NOTE: For the best lapping results, lightly tap the valve seat while rotating the valve back and forth between your hands.
CHECKING THE VALVE SPRINGS The following procedure applies to all of the valve springs. Measure: · Valve spring free length "a" Out of specification Replace the valve spring. Valve spring free length Intake 40. 38 mm (1. 59 in) <Limit>: 38. 36 mm (1. 51 in) Exhaust 40. 38 mm (1. 59 in) <Limit>: 38. 36 mm (1. 51 in)
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VALVES AND VALVE SPRINGS
EAS00245
INSTALLING THE VALVES
The following procedure applies to all of the valves and related components. Measure: · Compressed valve spring force "a" Out of specification Replace the valve spring. Installed length Compressed valve spring force (installed) 171. 0-197. 0 N at 35. 00 mm (17. 44-20. 09 kg at 35. 00 mm, 38. 44-44. 29 lb at 1. 38 in) 2. Lubricate: · Valve stem "1" · Valve stem seal "2" (with the recommended lubricant) Recommended lubricant Molybdenum disulfide oil
3. Measure: · Valve spring tilt "a" Out of specification Replace the valve spring. Install: · Valve "1" · Valve spring seat "2" · Valve stem seal "3" · Valve spring "4" · Valve spring retainer "5" (into the cylinder head)
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VALVES AND VALVE SPRINGS
NOTE: · Install the valve spring with the larger pitch "a" facing up. Install: · Valve cotters NOTE: Install the valve cotters by compressing the valve spring with the valve spring compressor "1" and the valve spring compressor attachment "2". [. . . ] Spark plug · Incorrect spark plug gap · Incorrect spark plug heat range · Fouled spark plug · Worn or damaged electrode · Worn or damaged insulator · Faulty spark plug cap 3. Ignition coil · Broken or shorted primary or secondary coils · Faulty spark plug lead · Cracked or broken ignition coil 4. Ignition system · Faulty ECU · Faulty crankshaft position sensor · Broken A. C. magneto rotor woodruff key
EAS28510 EAS28550
JUMPS OUT OF GEAR Shift shaft · Incorrect shift pedal position · Improperly returned stopper lever Shift forks · Worn shift fork Shift drum · Incorrect axial play · Worn shift drum groove Transmission · Worn gear dog
EAS28570
FAULTY CLUTCH Clutch slips 1. [. . . ]