Correctly installing and maintaining your motor bolts is important to prevent cross-threading, damaged threads and corrosion.

If a motor plug bolt does not start smoothly or you feel resistance while tightening, stop immediately. Do not force the bolt, as this can damage the bolt or the threaded hole in your motor plug.

For instructional video see: Correct Motor Bolt Application, Care and Repair

Bolt Thread Maintenance

Regular maintenance can help prevent corrosion and keep your motor bolts operating smoothly.

Remove and lubricate the bolts regularly

Remove the motor bolts regularly and apply a suitable lubricant to the threads.

This helps reduce corrosion, particularly when the motor is regularly exposed to salt water.

Keep the threaded holes clean

Sand and debris can become trapped inside the threaded holes and prevent the bolts from engaging correctly.

To clean the threads:

1. Use a damp cotton bud/earbud.
2. Carefully clean inside the threaded hole.
3. Remove any sand, salt or other debris.
4. Allow the area to dry before reinstalling the bolt.

Tip: Regularly removing and cleaning the bolts is much easier than trying to repair damaged threads later.

Cleaning Up Damaged or Dirty Threads

If your motor bolts are not going in smoothly or appear to be entering the threaded hole at an angle, the threads may need to be cleaned or repaired.

Do not force the bolt into the hole.

A suitable tool for cleaning up the threaded holes is an:

Sutton Tools M4 x 0.7 Intermediate Hand Tap – Bunnings Australia

Using the tap

A Sutton Tools M4 x 0.7 Intermediate Hand Tap can be used to carefully clean and restore the existing M4 x 0.7 threads.

If you are not confident using a tap or the threads are significantly damaged, we recommend contacting Foil Drive Support before attempting the repair.

Important: The tap is intended to clean up the existing threads. Do not force it or attempt to create a new thread.

Common Questions

How tight should the motor bolts be?

The motor bolts only need to be finger tight. Do not overtighten them.

What should I do if a bolt is difficult to tighten?

Stop immediately.

Remove the bolt and check that it is straight and that both the bolt and threaded hole are clean and free from debris.

Never force a bolt that is not turning smoothly.

Why won't my motor bolt go in straight?

Sand, debris, corrosion or damaged threads can prevent the bolt from entering correctly.

Remove the bolt, clean the threaded hole and inspect the bolt threads before trying again.

Can I use a power driver to install the bolts?

We recommend installing the bolts carefully by hand. The bolts only need to be finger tight, and using excessive torque can damage the threads.

How often should I remove and lubricate the bolts?

Regularly remove, clean and lubricate the bolts, particularly if your system is frequently used in salt water.

What size tap do I need to clean the threaded holes?

The motor threaded holes use an M4 x 0.7 thread. The recommended tool is an M4 x 0.7 Intermediate Hand Tap.