Piston -VESPA- Vespa 150cc (1959-) - Vespa VBA, VBB, VGLA, VGLB - 58.6mm (4th oversize)

Piston - VESPA Nose piston- Vespa 150 cc from year 1959.

Replacement piston for the 150ccm cylinders of the Vespa models VBA, VBB, VGLA, VGLB -
58,6mm is the 4th oversize.
Nose pistons are used in cross-flow scavenged two-stroke engines to keep the fresh gas flow away from the open exhaust. The nose sits on the piston crown and deflects the gas flow upward. The inlet cross-section can be larger than in cross-flow scavenged engines with flat pistons. Nose pistons also cannot prevent fresh gas from escaping into the exhaust at all loads and speeds, and they cause an unfavorable combustion chamber shape. After reverse scavenging was developed in the 1920s, cross-scavenged engines became less important.

TIP: Always install piston rings carefully. Piston rings made of cast material are only elastic to a limited extent and break relatively quickly.

(TW180122)