Tuning Introduction for Modern Vespa at SIP Scootershop

Tuning. With tuning, the trip to Corsica becomes a reality and does not remain a lifelong dream. With a tuned engine, the pulse leaves sleep mode. Tuning is one of the last adventures of civilisation and the escape from our so regulated everyday life.


Commonly, 50 cc scooters are throttled by a Vario ring, constrictions in the air filter or in the inlet duct. In order to be able to maintain the 45 km/h maximum speed, they are also throttled by a speed limiter in the CDI.

Maximum models also have a speed limiter as standard. This is not in order to maintain a legal maximum speed, but as "life insurance" against uncontrolled revving of the engine, caused for example by a broken V-belt. Tuning CDIs also have a cut-off speed. However, this is somewhat higher than that specified by the manufacturer. Basically, dethrottling the vehicle or replacing the CDI is the prerequisite for further tuning steps.


Up to the standard speed limit, optimising the drive is probably the easiest way to optimise the vehicle's performance. The additional speed achieved is marginal, but the increased fun factor due to improved acceleration and constant power clearly speak for optimising the drive.
Even replacing the V-belt, the complete variator such as the MALOSSI Multivar or simply the variator pulleys achieves noticeable differences. The drive tuning is rounded off by, for example, a MALOSSI Delta Clutch with optimised friction linings for less slippage or by replacing the converter unit.

If the vehicle is already at its top speed and you notice that there is still room for improvement, try replacing the gearbox and increasing the transmission ratio. You will be thrilled! If you are not sure about the composition of the drive components, we recommend that you use our drive tuning kits. Here we have put together simple and effective kits for you.


While the exhaust system or the exhaust resonance plays a decisive role on 2-stroke scooters, it serves more as a sound level reduction on 4-stroke vehicles. The replacement of a 4-stroke system brings only a slight increase in performance compared to 2-stroke systems, also due to the different functioning of the two engines. The advantages of a 4-stroke scooter system are clearly in the area of acoustics!


By changing the cylinder, only the displacement is changed in the case of a 4-stroke engine, and the displacement and timing are changed in the case of a 2-stroke scooter engine. More displacement leads to more torque and more revs, consequently also to more power and a higher top speed. Of course, there are also differences in material. Standard cylinders are usually made of low-cost grey cast iron. Sport cylinders use aluminium. These cylinders have a shorter warm-up and start-up time, are more forgiving of jams and are much more efficient at dissipating heat than their cast iron counterparts.

Valves and the camshaft play an important role in 4-stroke engine tuning. Whereas with a 2-stroke cylinder the high degree of filling is achieved by wide overflow valves, with 4-strokes this has to be done by enlarged and flow-optimised valve disks and/or/also by a "sharp camshaft". With the MALOSSI Power Cam, for example, the cam radius is modified so that the intake and exhaust valves are open longer. An "All in One" system is found in the MALOSSI V4 Head. Massively enlarged valve disks promise up to 25% more power.


4-stroke carburettors are almost always so-called equal-pressure carburettors. Since 4-strokes generate very strong negative pressure on the intake side, the slide of a classic slide carburettor would be quite difficult to move in the part-load range. The diaphragm in the equal-pressure carburettor does this work for you, because it works with negative pressure. The rider merely moves the throttle valve in front of the throttle slide with the throttle cable.

Larger, or simply higher quality, carburettors increase engine performance. That is why we have all original carburettors and larger 4-stroke carburettors such as the MIKUNI TM33 flat slide with accelerator pump in our range. As with the 2-stroke, the carburettor must be tuned accordingly when the displacement is increased. Our tuning nozzle sets are therefore particularly practical.

With injection engines (i. e. injection), the fuel supply is regulated via the injection module. There is a difference between models with and without a lambda sensor. Modern Vespa injection engines over 125 cc are all equipped with lambda sensor. These engines do not need to be tuned for small changes. Based on the exhaust gas values, the Lambda control automatically balances the fuel quantity upwards. These values are set quite lean in order to comply with the exhaust emission standards. By installing a so-called Lambda Emulator, the standard parameters are expanded and one obtains a much more agile vehicle with better response behaviour during load changes.

With a massive increase in engine capacity, however, the original injection module and its defined parameters reach their limits. The only solution is to replace it with, for example, the adjustable MALOSSI Forcemaster2 injection module. Similar to a carburettor tuning, the fuel quantity can be adjusted manually. Lambda emulators can also be used!

We distinguish four tuning classes

Entry-level tuning

Inexpensive entry-level class. For anyone who only wants to install a few parts: better trigger, slightly higher top speed, more power. There is no increase in displacement.

  • Light variator pulleys MALOSSI

  • variator rollers Dr. Pulley

  • harder clutch springs MALOSSI

  • MALOSSI sports air filter

  • MALOSSI Torsion Control

Sport Tuning

Intended for the normal everyday rider who does not demand top performance, but wants to achieve more power on a durable basis with relatively little effort. Faster acceleration and more powerful on hills or in 2-man operation. Slightly higher top speed.

  • Sport variator

  • Sport V-belt

  • Sport counterpressure spring

  • Oil filter

  • Sport air filter/insert

Sport Plus Tuning

This builds on previous tuning levels. The target group is the performance-hungry everyday and touring rider. The conversion to a sports exhaust and the optimisation of the CDI or fuel injection have a significant effect on the scooter's characteristics. Agile take-off, nice pull-through and higher top speed are the result of this conversion.

  • Sport exhaust system

  • Sport clutch

  • Sport clutch bell

  • Lambda Emulator

  • Sport CDI

  • Injection module

  • Torque Drive

Sport Plus High End Tuning

King class - displacement instead of revs. The "High End" tuning level builds on the previous levels and is not intended for stick-on tuners. Here you can achieve the maximum power and top speed. Tuning experience is recommended for this tuning level. It is advisable to install the complete range, because the parts are matched to each other!

  • Sport cylinder

  • Sport camshaft

  • Sport valves

  • Sport valve springs

  • Sport gear ratio

  • Sport crankshaft

  • Gear ratio