The OH engine valve tappets are a simple screw in type with a lock nut . They tend to develop a pocket or crater at the point where the valve stem hits them , making it impossible to accurately set your tappet clearances . I have worked out a simple but effective method of refacing the tappets, using a ordinary bench drill and a tool sharpening stone .
Step 1 . Unscrew the locknut and mount the tappet in the chuck of the bench driill , set up the drill for its lowest speed , in my case this was 500 RPM . Make sure the base plate is exactly flat eg, 90 degrees to the drill .
Step 2 . Buy a new hand tool sharpening stone , ( very cheap to buy ) they are usually around 6 inches long by 2 inches wide . Use two G clamps to clamp the stone across the base plate .
Step 3 . Turn the drill on and gently lift the base plate and stone up to the tappet face eg. slide the base up the mounting post . Use a slow backward and forward sideways motion across the tappet face , the stone will grind a smooth flat new face onto your tappet . Some kerosene helps the process . Relocate the stone every few minutes to avoid making a wear line in the stone . |
