Active 50

Some of the green engine cover has been removed in order to install a tuned pipe.

The Active 50 is a 51.7cc 2-stroke engine produced by Active, an Italian engine manufacturing company. It is legendary as a big bore scooter engine because of its performance and reliability.

Technical SpecificationsEdit


Active 50 cylinder

51.7cc cylinder

Active 50 piston

51.7cc piston

Active 50 case and piston

51.7cc case and piston

The Active 50 is a high performance, high reliability engine. It features a precision ground, steel plated cylinder, a light weight piston and a large (relative to other scooter engines) 51.7cc displacement.


There are currently no distributors of this engine in the United States, but parts are available. Since this engine is relatively exotic, the cost of replacement parts is high.

Performance EnhancementsEdit

Tuned pipesEdit

Puzey Power Pipe. The Puzey Power Pipe was designed specifically for use with this engine on the Evo 2x, Evo 2 or Evo SPX scooters. Because of this, no modifications should be necessary to adapt it. On the Active 50, the Puzey Power Pipe will cause a significant increase in low-mid range power, but will not increase RPMs noticeably.

Puzey Race Pipe.

ADA GSR40 Pipe.


Porting is somewhere this engine really shines. This engine is no toy to begin with, but porting can squeeze quite a bit more out of it. With a skilled hand, ported Active 50s have lived long lives pushing stand up scooters to the 50s.

Head kitsut the performance, RPM's are lost due to the weight of ADA's piston. The Active 50's piston has a different squish angle and will not work with ADA's dome without modification. Edit

History with Evo's 2xEdit

Industrial ApplicationsEdit

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