Motorcycle valve lapping
Valve lapping is a process in which a small amount of abrasive paste is applied to the valve and valve seat in a motorcycle engine to smooth and reshape the surface.
Valve lapping paste is a type of abrasive paste used in the process of lapping valves in a motorcycle engine. The paste is used to smooth and polish valve surfaces, which helps improve the seal between the valve and valve seat. This improves overall engine performance by reducing air and fuel leaks and increasing engine power and efficiency.
Different types of valve lapping pastes are available, each with a different grit, which are suitable for different stages of lapping. Grit refers to the size of the abrasive particles in the paste:
- Coarse-grained, this type of paste is usually used for initial lapping of valves. It has a high concentration of abrasive particles that can quickly remove any rough or uneven surfaces on valves.
- Medium-grained used for further lapping of valves after initial lapping with coarse-grained paste. It has a lower concentration of abrasive particles than coarse-grained paste, which is less aggressive and can be used to achieve a finer finish.
- Fine-grained for final lapping of valves. It has the lowest concentration of abrasive particles that can be used to achieve a highly polished finish on valves.
It is important to follow the manufacturer's instructions when using valve lapping paste and use the correct grit for the lapping stage. It is also recommended to use a lapping tool to apply the paste evenly, and to use a micrometer to measure valve heights and make sure they are within the proper tolerance.
How to lapped motorcycle valves with valve lapping paste
Lapping paste is used to grind and smooth metal surfaces, such as the faces of motorcycle valves. To use lapping paste, follow these steps:
- Clean the valve face: Remove any dirt, oil or residue from the valve face to ensure proper adhesion of the lapping paste.
- Apply the paste: Apply a small amount of lapping paste to the valve face and spread it evenly.
- Lapping the valve: Hold the valve with a tool and rotate it against the valve seat, applying light pressure. This will help grind off any rough or uneven surfaces. Continue this process until you have a smooth and uniform surface of the valve and seat.
- Clean the valve: Remove the lapping paste and clean the valve and seat with a clean cloth and solvent. Make sure all the paste is removed, as any residue can cause problems when the engine is running.
- Repeat the process: If necessary, repeat the process for each valve.
Note: This process requires patience and caution. Avoid applying too much pressure or grinding the valve too aggressively, as this can damage the valve or seat.