Sensor magnet installation

Note, however you mount the magnets, you must make sure that they CANNOT COME OUT during engine running. If a magnet were to fly out during engine run up, the magnet could hit you or bystanders and cause injury.

The instructions that come with the kit suggest several possibilities to mount the sensor magnets in the spinner, so naturally I rejected those in favor of my way. No one in this hobby would do that!! Besides, I had plastic spinners which I worried as to how to PERMENTALTY attach the magnets.


I am using Super Tigre .45’s, so I removed the bearing cover and prop mount and drilled a pilot hole, that clear the internal webs. Note, if you are concerned about a balance issue, you could mount and second magnet on the other side. At such close proximity to the centerline of the engine, I did not feel this would be a problem.

The required hole is 3/16” and DO NOT REAM IT OUT. You need to keep the hole a tight fit.

Here is the magnet that is inserted into the predrilled hole. Make SURE the previously identified pole of the magnet is facing outward. At this point, I took a punch and slightly staked or crushed the outside of the hole to tighten the fit for the magnet. This was to make sure that the magnet could not slide out.

The magnet was inserted into the hole from the inside with 30 minute epoxy or Liquid Steel Epoxy and pushed into place flush with the outside with a small pair of pliers. DO NOT CRUSH the spinner back plate. Add a small additional dab of epoxy on the inside of the back plate and let dry. You must test fit the back plate after drying to make sure it does not rub the crankcase nose when it is reinstalled. After the glue dries for at least 24 hours, push on the magnet firmly to make sure it is tight.


Here is the outside of the back plate with very light staking of the hole, with the sensor magnet mounted flush. Make sure it cannot slip out.