Racing cylinder 125-150 ccm, 3 ÜS for Vespa 125 GTR 2°-TS/150 Sprint 2°-Super 2°/P125-150X/PE/Lusso/MY/P150S/Cosa/LML Star by SIP Scootershop
Customers ask - SIP answers
"Do I need to run in my cylinder?"
Yes. The piston is travelling at an impressive speed in the cylinder bore. At 20 m/sec, that's 72 km/h after all. The piston, rings and cylinder must fit together perfectly. These tolerances are infinitesimally small, in the micrometre range. During the running-in period, the moving parts rub against each other to achieve a perfectly coordinated shape. The aim of the running-in process is therefore not, as is often claimed, to produce the smoothest possible surfaces, but to produce components that fit together as well as possible. By the way, the recommended running-in time is not 1500 km or similar fantasy figures, but one hour! Warm up the engine carefully, avoid maximum load, increase power output slowly.
Caution: The engine must be run in again if any of the components (pistons, piston rings (especially!) or cylinders) have been replaced.
