The overhauled engine is bench tested (running-in) without load for the following cycle: at a speed of 820-900 min-1 - 2 minutes; 1000 min-1 - 3; 1500 min-1 - 4; 2000 min-1 - 5 minutes.
Having installed on the stand and started the engine, check: if there is any leakage of coolant or fuel between mating parts, from pipeline connections and through gaskets; is there any oil leakage from under the oil filter sealing ring and through the gaskets; oil pressure; setting the ignition moment; idle speed; tightness of the connection of the carburetor with the inlet pipeline; there are no extraneous knocks. If extraneous knocks or malfunctions are found, stop the engine, eliminate them, and then continue testing.
If oil leaks between the engine oil sump and the cylinder block, tighten the bolts to the recommended torque. If the oil leak does not stop, check the condition of the gaskets and, if necessary, replace them.
If oil leaks through the gasket between the cover and the cylinder head, check the gasket and rubber bushings on the studs of the cylinder head cover. If necessary, replace the gasket and bushings, following the recommendations outlined in Sec. «Engine Assembly».
Since the engine has not yet run in after the repair and the friction of the working surfaces of new parts has a significant resistance to rotation, a certain period of running in is necessary. This applies in particular to those engines on which pistons, connecting rod and main bearing shells have been replaced, crankshaft journals have been ground, and cylinders have been honed.
Therefore, during the running-in of a repaired engine, it should not be brought to maximum loads. The engine run-in on the vehicle should continue at the speeds recommended for a new vehicle.