User manual YAMAHA XT350-1998

[. . . ] Repair and maintenance work attempted by anyone without this knowledge is likely to render the vehicle unsafe and unfit for use. Yamaha is continually striving to improve all its models. Modifications and significant changes in specifications or procedures will be forwarded to all authorized Yamaha dealers and will appear in future editions of this manual where applicable. NOTE: Designs and specifications are subject to change without notice. _ EAS00004 IMPORTANT MANUAL INFORMATION Particularly important information is distinguished in this manual by the following. [. . . ] Install: decompressor lever pin 1 decompressor lever 2 NOTE: Install the decompressor lever pin 1 and decompressor lever 2 in the camshaft 3 as shown in the illustration. _ 3 4. Install: camshaft 1 NOTE: Install the camshaft on the slot a facing up. Lubricate: rocker arm shafts a 1 Recommended lubricant Engine oil 1 2 3 6. _ Install: exhaust rocker arm 1 exhaust rocker arm shaft 2 intake rocker arm intake rocker arm shaft NOTE: Use a slide hammer bolt 3 to install the rocker arm shaft. Make sure the rocker arm shaft (intake and exhaust) is completely pushed into the cylinder head. Install: camshaft retainer camshaft retainer bolts LT T. 10 Nm (1. 0 m kg, 7. 2 ft lb) R. 5 - 22 VALVES AND VALVE SPRINGS EAS00236 ENG VALVES AND VALVE SPRINGS 1 2 2 3 6 7 New M 2 3 6 M 1 2 3 6 7 New 3 6 7 7 M New M 5 4 5 M 4 Order 1 2 3 4 5 6 7 Job/Part Removing the valves and valve springs Cylinder head Rocker arms/rocker arm shafts/camshaft Valve cotter Valve spring retainer Valve spring Exhaust valve Intake valve Valve stem seal Valve spring seat Q'ty Remarks Remove the parts in the order listed. Refer to "ROCKER ARMS AND CAMSHAFT". 8 4 4 2 2 4 4 Refer to "REMOVING THE VALVES" and "INSTALLING THE VALVES". For installation, reverse the removal procedure. 5 - 23 VALVES AND VALVE SPRINGS EAS00237 ENG REMOVING THE VALVES The following procedure applies to all of the valves and related components. NOTE: Before removing the internal parts of the cylinder head (e. g. , valves, valve springs, valve seats), make sure the valves properly seal. _ 1. Check: valve sealing Leakage at the valve seat Check the valve face, valve seat, and valve seat width. Refer to "CHECKING THE VALVE SEATS". Pour a clean solvent a into the intake and exhaust ports. Apply Mechanic's blueing dye (Dykem) onto the valve face. Install the valve into the cylinder head. 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. _ LLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLL 5 - 27 VALVES AND VALVE SPRINGS 4. Lap: valve face valve seat ENG NOTE: After replacing the cylinder head or replacing the valve and valve guide, the valve seat and valve face should be lapped. _ a. Apply a coarse lapping compound a to the valve face. CAUTION: _ MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM Do not let the lapping compound enter the gap between the valve stem and the valve guide. Apply molybdenum disulfide oil onto the valve stem. Install the valve into the cylinder head. 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. _ e. [. . . ] 9-3 FUEL SYSTEM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-3 FAULTY GEAR SHIFTING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-3 SHIFTING IS DIFFICULT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-3 SHIFT PEDAL DOES NOT MOVE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-3 JUMPS OUT OF GEAR. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-3 FAULTY CLUTCH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-3 CLUTCH SLIPS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ]