Gen II
User Manual
4-5 – Propeller Balance
Chapter 4
Revision 2.2, Apr 2020
Place the protractor over the spinner with the Rotation indicator pointing in the direction
of rotation (forward looking aft) and the 360-degree points aligned with the position of
the reflective tape.
Read the numbers in the circles, and then interpolate values of the unmarked incremental
lines to locate the desired angle.
Case Bolt Adapter Set
An eight-piece case bolt adapter set with nut sizes 1/4 to 7/16 NF and NC threads is included in
the propeller balancing kit. The stud portion uses 1/4 x 28 threads. To use the bolts/nuts during a
typical propeller balance, select the adapter from the set to match the case bolts of a typical
opposed engine. Attach the adapter nut end to the exposed case bolt threads then slide the right-
angle mount over the stud end and secure with the supplied nut. Two sets of the adapters are
required for dual-engine balancing.
Tackle Box
A multi-compartment, high-impact plastic, tackle box is included with the propeller balancing
kit. The box has ample storage space for vibration sensors, vibration sensor mounts, and the case
bolt adapter set. It may also serve as storage for AN washers used as balance weights.
Right-Angle Sensor Mount
The right-angle sensor mount shown in the left portion of the illustration below is made of
anodized aluminum and designed to be mounted directly on the engine case bolt or to the case
bolt adapter, shown in the right portion of the illustration below. The mount has a 1/4 x 28-
threaded hole for the vibration sensor and a ¼-inch unthreaded hole for the case bolt adapter
stud.
