Yamaha YZF-R1 2007 Service Manual

VALVES AND VALVE SPRINGS5-27e. Apply a fine lapping compound to the valveface and repeat the above steps.f. After every lapping procedure, be sure toclean off all of the lapping compound fromthe valve face and valve seat.g. Apply Mechanic’s blueing dye (Dykem) “b”onto the valve face.h. Install the valve into the cylinder head.i. Press the valve through the valve guideand onto the valve seat to make a clearimpression.j. Measure the valve seat width “c” again. Ifthe valve seat width is out of specification,reface and lap the valve seat.▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲EAS24310CHECKING THE VALVE SPRINGSThe following procedure applies to all of thevalve springs.1. Measure:• Valve spring free length “a”Out of specification → Replace the valvespring.2. Measure:• Compressed valve spring force “a”Out of specification → Replace the valvespring.Valve spring free lengthFree length (intake)39.79 mm (1.57 in)Limit37.80 mm (1.49 in)Free length (exhaust)38.42 mm (1.51 in)Limit36.50 mm (1.44 in)Installed compression springforce (intake)171–197 N (38.44–44.29 lbf)(17.44–20.09 kgf) at 35.50 mm(1.398 in)Installed compression springforce (exhaust)202–232 N (45.41–52.15 lbf)(20.60–23.66 kgf) at 33.00 mm(1.299 in)b. Installed lengthManuals by Motomatrix / www.motomatrix.co.uk / The Solution For Lost Motorcycle Coded Keysemail: info@motomatrix.co.uk