Vespa Primavera ET3 125 Simonini 180° Reverse Exhaust

The -Simonini 180°- for the Vespa V50, ET3 125, PV125, PK50-125 is a classic of small frame tuning. For a long time it was considered the most uncompromising solution for engines with a lot of smoke. So one or the other Quartermile crate was also sighted with the 180°.

But for this the cylinder has to be mounted turned by 180°. The outlet then points in the direction of travel. In principle every cylinder can be mounted rotated. The advantage of the rotated mounting is the better flushing behaviour of the cylinder. The incoming fresh gas does not mix so much with the old gas anymore.
Cylinders like the direct intake Malossi 136 cc or the legendary Polini 133 cc twin intake always protrude very far out of the side cover without further modifications. In addition, a piece of the chassis almost always has to be cut out.
The performance of the Simonini 180° does the right thing on the road. In combination with a suitable engine setup the Simonini pushes forward powerfully and lets the front wheel prance slightly over the asphalt. The 180° from Simonini is quite pointed. This makes it an absolute high end solution and when using a short fourth gear the thing turns without end.