Current technology provides the means of manufacturing engine parts with unimaginable precision however they still far short of achieving the near perfect fit that a proper break-in will provide. Break-in, is the allowance of the machined parts in the engine engine to conform to each other. This conforming or mating specifically of the ring and cylinder surfaces is the ultimate goal of a proper break-in. Mating these two specific parts will produce a very tight seal in each cylinder. A tight seal is very important because of the intense pressure diesel engines operate under. Mating helps prevent the escape of unburned fuel and pressurized gasses into the crankcase, while further preventing crankcase oil from entering the cylinder above the top compression ring. The blow by also causes a loss of pressure and results in lack of power.

Friction causes heat and until the break in occurs extra heat and most of the wear and tear will happen during this period. Break in your engine before using it! Don’t forget oil will become contaminated faster because of combustion blow by fumes and metal that is ground away during the mating process. The oil should be changed at at the first 25 hours.

This is an important time for an engine. You should not subject the engine to significant loading for the first 25 hours or more however some load IS desirable since the heat and friction is also needed for the break in to occur. Excessive heat will burn oil and cause it to harden leaving an enamel like residue on the cylinder wall, commonly known as oil glazing and prevents the mating from occurring so small gaps between rings and cylinder surfaces will never seal. The same applies to use synthetic oil during the breakin period. It will also prevent break in from happening. Only use synthetic oil after the break in period.

A moderate loading is the key to a proper break in. 1/2 the rated power may be ideal. While some manuals suggest decreasing the RPM it is not easy to do on generator motors since they have a fixed run or stop position that locks into place on the throttle. If you can, secure it for this process for a break in period so are running it at half the RPM you will benefit from it in the long run. Obviously you can not use the generator until the normal speed is restored.