by Had Robinson
updated February 10, 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. Miniplane, unfortunately, has only the briefest instructions that are not helpful e.g. "You must run-in the engine before flying. Do not rev up for five minutes while running-in...." That is the extent of it!
Proper break-in will provide
you with a better running engine and considerably longer engine life.
Most engines are not properly broken-in. It takes time. Remember
that running at full throttle on a new engine for more than brief periods
should never be done.
The break-in 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. All pilots 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 for their engines. The reason is that it causes the engine to run hotter (leaner), even causing 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.
A new engine generates a lot more friction (heat) because the moving parts of the engine have tighter clearances. It can more easily seize than an engine with many hours. The break-in procedure allows the space between moving parts to increase slightly to the designed value. It also allows important moving surfaces to seat and seal properly.
This break-in procedure is extensive and 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.
- 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.
- 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).
- 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).
- 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).
- 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.