Things You'll Need
Instructions
Watch the swing of the pendulum and listen to its sound. The movement of the pendulum should be even and regular, and its sound a steady "tick-tock."
Move the pendulum bob downward if the cuckoo clock runs too fast. The pendulum bob is the weight at the bottom of the pendulum. On cuckoos, they are often shaped like leaves.
Check the time on the German cuckoo clock again after it has been running for a little while. If it still noticeably fast, adjust the pendulum bob downward once again. Keep adjusting until the clock appears to be keeping accurate time.
Move the pendulum bob upward if the cuckoo clock is too slow. This has the effect of "shortening" the pendulum and making it run faster.
Check the German cuckoo clock's time again in a little while. If it is still too slow, shorten the pendulum again by raising the pendulum bob.