How to fine-tune the size of the old Yamaha 550

2. Secondly, align the T-shaped notch of the magneto with the notch on the gear box.

3. Then unscrew the screw on the cylinder head.

At this time, you can see that the rocker arm, tail and valve of exhaust valve and intake valve are all dry.

5. Finally, the screw at the end of the valve stem can adjust the clearance of the valve.