Note:
- The valves should only be adjusted when the temperature of the cylinder head is below 38°C.
- After adjustment, loosen the crankshaft pulley bolt, then retighten it to 20 Nm (2.0 kgf/m) and tighten by 90°.
1. Disconnect the breather hose, then remove the air cleaner cover.
2. Remove the cylinder head cover.
Note: When installing the cylinder head cover, refer to par. «Installation».
3. Remove the top cover.
4. Set the piston of cylinder No. 1 to TDC on the compression stroke. Label «UP» (top) on the camshaft pulley should be on top, and the TDC marks should be aligned with the top surface of the cylinder head.
5. Adjust the valves on cylinder #1:
- Inlet: 0.20mm±0.02mm
- Outlet: 0.25mm±0.02mm
6. Loosen the locknut and turn the adjusting screw until the feeler gauge moves in and out with some resistance.
Note: Do not overtighten the locknuts as the rocker arms are made of aluminum.
7. Tighten the locknut and check the gap again. Repeat the adjustment if necessary.
8. Turn the crankshaft 180" counterclock-wise (camshaft pulley rotates 90°). Label «UP» (top) must be on the outlet side. Adjust the valves on cylinder #3.
9. Rotate the crankshaft 180°counterclockwise and bring the No. 4 cylinder piston to TDC. Both TDC notches will appear again. Adjust the valves on cylinder #4.
10. Rotate the crankshaft 180°counterclockwise and bring the #2 cylinder piston to TDC. Label «UP» (top) should be on the intake side. Adjust the valves on cylinder #2.