Breaking in the Minari engine
All new engines must be broken in properly for both maximum performance and long engine life. It takes about (10) hours to do it properly. Here is their procedure (translated from the Italian) with additional notes from other sources. New engines generate a lot more heat and this is what can cause them to seize unless they are carefully broken in.
1. When you start the engine for the first time, run it at a fast idle until it reaches normal operating temperature (when the cooling fins of the engine are too hot to touch) and then for at least an additional (10) minutes.
2. Readjust the carburetor at this time (see the “Basic Carburetion” instructions on page EN 15 and page IT 8 of the user manual).
Readjustment is required whenever there is any change in the engine operating conditions such as ambient operating temperature, changes in altitude, or replacement of major engine parts like the piston, cylinder, or cylinder head.
3. During the first (20) liters of fuel use, do NOT run the engine at full throttle/maximum RPM for more than (5) minutes. If you have a CHT, keep the operating temperature well below the maximum of 200-220ºC (390-420ºF) until the engine is fully broken in. (A CHT is not mentioned or required by Minari but it is an extremely good idea to have one and to be gentle on the engine when it is new.)
4. After the first few hours of use, the belt tension must be re-adjusted. A too loose or too tight belt can damage the engine.