From the life of a journeyman mechanic - high oil consumption
10/24/2017
Once again, excessive oil consumption was under discussion. This time it concerned a scooter with a four-stroke engine. As it was a new vehicle known to the workshop, which was still undergoing regular service work, the oil loss was considered proven. The amount of oil had already had to be topped up several times after inspection. A thorough cleaning of the engine and an inspection for oil loss to the outside after a short drive were unsuccessful. So it was time to remove the cylinder and look for the fault inside the engine.
However, we were astonished (and disappointed) to find the cylinder bore, piston and piston rings in perfect condition. No seizure, perfect piston contact pattern, no seized piston ring - everything was in perfect order. The engine was reassembled using new gaskets and - as was feared - returned to the workshop a short time later with the same complaint.
This time, a different journeyman was assigned to the job, and after some fruitless efforts, he too was finally able to examine the piston. However, he did not limit himself to looking at these parts, but began to lift the rings out of their grooves. When the oil ring was pulled off, there was a slight "crack", and in front of him lay the ring, broken in two, and thus the solution to the mystery.
The crack proved that the ring had been broken for some time. The lower half of the slit ring had still held it together, but only with a little tension. On closer inspection, the part of the ring that was no longer attached due to the reduced clamping force was also clearly visible. Oil was constantly leaking into the combustion chamber at these points. After fitting a new oil ring, the mysterious oil consumption in this engine was once again solved.
This text comes from issue 19 of the 1957 edition of the magazine" Krafthand".
