STRUCTURE AND OPERATION Valve Mechanism 1 Exhaust valve 2 Inlet valve 3 Camshaft 4 Tappet 5 Push rod 6 Rocker shaft 7 Rocker shaft spring 8 Rocker 9 Rocker shaft bracket 10 Valve cap 11 Valve cotter 12 Upper retainer 13 Outer valve spring 14 Inner valve spring 15 Valve stem seal 16 Valve guide The valve stem seals 15 are fitted onto the valves 1 , 2 to control the amount of lubricant flowing onto the sliding surfaces of the valves 1 , 2 and valve guides 16 . The valve springs 13 , 14 are unevenly pitched to prevent abnormal vibration at high speeds. To prevent the inner and outer springs from meshing with each other, the springs are wound in opposite directions.
To facilitate removal and reinstallation of the camshaft from the rear end of the crankcase, the diameter of each bushing is smaller toward the front of the engine. Connecting Rods 01926 1 Connecting rod bushing 2 Connecting rod 3 Connecting rod bearing 4 Connecting rod cap 5 Connecting rod bolt A : Alignment mark B : Weight mark stamp (A, B, C, D, E, F, G, H, I, V, W, X, Y, Z) 13622 11-4