Yamaha YZF-R1 2007 Service Manual

VALVES AND VALVE SPRINGS5-26▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼a. Apply Mechanic’s blueing dye (Dykem) “b”onto the valve face.b. Install the valve into the cylinder head.c. Press the valve through the valve guideand onto the valve seat to make a clearimpression.d. Measure the valve seat width.NOTE:Where the valve seat and valve face contactedone another, the blueing will have beenremoved.▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲4. Lap:• Valve face• Valve seatNOTE:After replacing the cylinder head or replacingthe valve and valve guide, the valve seat andvalve face should be lapped.CAUTION:ECA4C81012This model uses titanium intake valves.Titanium valves that have been used to lapthe valve seats must not be used. Alwaysreplace lapped valves with new valves.NOTE:• When replacing the cylinder head, replacethe valves without lapping the valve seatsand valve faces.• When replacing the valves or valves guides,use new valves to lap the valve seats, andthen replace them with new valves.▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼a. Apply a coarse lapping compound “a” tothe valve face.CAUTION:ECA13790Do not let the lapping compound enter thegap between the valve stem and the valveguide.b. Apply molybdenum disulfide oil onto thevalve stem.c. Install the valve into the cylinder head.d. Turn the valve until the valve face and valveseat are evenly polished, then clean off allof the lapping compound.NOTE:For the best lapping results, lightly tap thevalve seat while rotating the valve back andforth between your hands.Valve seat widthValve seat width C (intake)0.90–1.10 mm (0.0354–0.0433in)Valve seat width C (exhaust)0.90–1.10 mm (0.0354–0.0433in)Manuals by Motomatrix / www.motomatrix.co.uk / The Solution For Lost Motorcycle Coded Keysemail: info@motomatrix.co.uk