Engine Break-In

by Had Robinson
updated August 1, 2020

If your paramotor has a specific break-in procedure, follow it carefully.  If not, the general steps below should be adequate to protect your engine and give it a long life.

Why break-in an engine?  The new moving parts fit together tightly and, as a result, create much more friction (and heat) until they wear a little bit.  Not giving these parts the right amount of time to wear and adjust to each other will cause excessive heating and will permanently damage them.  A proper break-in will provide a better running engine and longer life.  Sadly, most engines are not properly broken-in.  It takes time.  Remember that running at full throttle on a new engine for more than a minute should never be done.

The procedure can be done with the paramotor on your back.  If you are a new pilot, it is the perfect time to become more familiar with the feel and sound of your paramotor.  While doing the break-in fiddle with items around you like the buckles, the choke, etc.

The more the throttle is second nature, the safer pilot you will be.

It takes dozens of hours in the air to get comfortable with the throttle so you are not thinking about it.  We all have enough distractions as it is.

Do not increase the amount of oil in the fuel during the break-in period unless your engine manual specifically advises you to do so.  Polini, Minari, and Miniplane note that increasing the oil in the gasoline should not be done.  The reason is that it causes the engine to run hotter and may even cause it to seize.  DO WHAT THE ENGINE MANUFACTURER SAYS.  Do NOT listen or pay any attention to the BLOGS or anyone who thinks he knows more than the people who engineered and manufactured the engine.  (The source for adding more oil during break-in largely comes from outboard motor manuals.  These engines are water-cooled and cannot overheat.)

This break-in procedure can be used with any paramotor.  The procedure listed below takes about an hour (except for cool-down time) and is done on the ground.  After this is done, you may fly.

Put the engine on your back and take a walk.  Not only will you break the engine in but you will get used to it being on your back.  If you have a CHT installed, keep the temperature well below the specified maximum, usually 170ºC.  Here is a PDF of the steps below.  Print it out so you can refer to it while breaking in your engine.  The procedure below is from the Simonini manual and covers other engines, as well.

  1. Start the engine and let it idle until it is up to normal running temperature (cooling fins too hot to touch).  Idle it for another (10) minutes.  DO NOT EXCEED THESE TINES BECAUSE IT WILL FOUL THE SPARK PLUG.

  2. Vary the RPM to 4,500 RPM and back to idle at 1 minute intervals for 20 minutes.  Stop the engine and let it cool completely (about 30 or minutes).

  3. Start the engine.  Vary the RPM from idle to 4,500 RPM at 1 minute intervals for another 20 minutes.  Stop the engine and let it cool completely (about 30 or minutes).
     
  4. Start the engine and let it warm up for 10 minutes at a fast idle.  Vary the RPM from idle to full throttle (briefly) at 1 minute intervals for 20 minutes.  Stop the engine and let it cool off completely (about 30 or minutes).
     
  5. Check the head nuts for the correct torque.  This is very important.  THEY WILL LOOSEN!

At this point, you can fly.  Vary the throttle often during the break-in period.

DO NOT FLY AT FULL THROTTLE FOR MORE THAN A MINUTE UNTIL YOU HAVE RUN 10 LITERS OF GASOLINE THROUGH THE ENGINE!

IMPORTANT: Polini and Minari note that break-in is complete after two tanks (20 liters) of fuel has been consumed.  Be really easy on the throttle until (20) liters of fuel have been consumed.

All engines should have the head bolts/nuts checked after the first few hours of use as they ALL loosen up.  For the proper torque value, check the respective specification page for your engine.  The Top 80 value is 9 Nm.

Turkey Vulture