In addition, the 150-cc engine was fully rebuilt. Although the Vespa 2-stroke is a relatively reliable design, wear on certain components is inevitable. In particular the 2-stroke lubrication system gives only a minimal amount of lubrications to pistons and crank bearings, but at the same time the burnt oil (after combustion) will slowly build up in the muffler and around the exhaust port, which will greatly reduce performance.
During the rebuild of the engine the following components were replaced or reconditioned:
- Cases were cleaned and grit blasted
- New piston and rings
- Crankshaft assembly
- Crank and gear bearings
- Crank oil seals
- Complete gasket set