How do you calibrate a nortron 7300 wheel balancer?

- Mount a well-balanced 14" wheel

- Set the sensor positions directly in line with each side

- Set the rim diameter control to 14"

- Note that there are five trimpots accessable through the front panel. One in the center and two beneath each display.

- Execute repeated balance cycles until the tire is balanced as well as possible.

- Add a 4.0 ounce wheel weight to the front side at the position indicated on the display from the last cycle and execute a balance cycle.

- Adjust the trimpots beneath the display and repeat balance spin until the display reads 3.9 ounces and the indicated position is 180 degrees opposite the weight which should be at 6 o'clock.

- Remove the 4.0 ounce weight, spin for zero, repeat for the backside.

- Remove the 4.0 ounce weight and rebalance the tire for zero adjusting the center trimpot when the position fluxuates more than 45 degrees to 0.0 ounces on each side.

- Repeat 4.0 ounce weight/position adjustment above.

- If difficulty arises in getting a zero readout consider changing the drive belt.