Yamaha Cornets Owner's Manual - Page 10

Maintenance ■ Once or twice a month maintenance ● Piston and valve casing maintenance The trumpet's valves are designed with very little clearance between the piston and the casing therefore, it is very important that these precision parts be handled with care. 1. Wrap the cleaning rod with gauze leaving no bare metal exposed. Cleaning rod 4. Return the piston to its corresponding valve casing. After confirming that the number stamped on the piston matches the number stamped on the valve casing, carefully insert the piston straight into the valve casing with the number stamped on the piston facing the mouthpiece. Do not rotate the piston in the valve casing. Number Gauze * Exposed metal can result in damaged valve casings or pistons. 2. Remove dirt from the inside of the valve casings. 5. Apply valve oil to the piston. Valve oil 3. Remove dirt from the pistons. 22 * Do not apply too much oil. * If air does not pass through the instrument when the piston is fully depressed, the piston may be placed in the wrong valve casing. Make sure that the numbers stamped on the piston and valve casing match. The piston is the most important part of the trumpet. Never treat the pistons roughly, drop the piston, or let the piston fall, etc. If the piston becomes damaged or dented, never return it to the valve casing. Contact the dealer from whom you purchased the instrument.