Transmission, clutch and filter
Transmission, it starts here – The first thing to improve is the variator: it is essential to have a sufficiently robust transmission to be able to take advantage of the increase in performance. Just changing this part with another of higher quality leads to an improvement in performance that is immediately noticeable.
Clutch, change the spring – The original clutch (provided it is in good condition) can be fine if the tuning is not extreme, but it should be replaced if it is even a little worn. In any case, it is advisable to change the contrast spring, fitting one that is adequate for the new performance. It should also be said that the “special” springs are also easier to adjust: remember that a perfect calibration allows you to better exploit the power.
Filter, let it breathe – Another inexpensive but important operation to improve engine performance is replacing the air filter with a “racing” one. Be careful: external filters with the “visible” sponge are nice, but they are only good on the track. For road use, it will be enough to change the filter element inside the original filter box: with a few dozen euros you will allow the engine to breathe (and perform) better.
Exhaust and ignition
Only after working on the transmission and intake can you think about the most classic of modifications: the “muffler”. If you want to continue using the scooter on the road, look for an approved muffler: in this way the scooter will be in compliance with the code. If instead you have decided to use the scooter only on the track, you can mount a non-approved racing muffler. But be careful what you buy: the “pushed” exhausts are designed to perform best with 70 cm3 displacements (those of the various trophies) and on a normal moped they are not suitable. Before purchasing, inform yourself well.
A good preparation for the track can be completed with a “racing” ignition, which allows you to correctly manage the increase in rotation speed due to the tuning.
“Increased” displacement
70 cm3 – If the performance obtained with the modifications made so far does not satisfy you, you need to move on to much more demanding interventions. To really improve performance, you need to increase the displacement: no other modification will lead to such noticeable increases. There are kits on sale that allow you to increase the displacement by replacing the cylinder and piston.
This is the most common displacement, also because it is the maximum allowed in the various championships dedicated to scooters. This processing allows for a good increase in performance, while maintaining acceptable reliability. The available kits are in cast iron or aluminum:
Cast iron – They cost less than aluminum ones, but above all they can be repaired easily (and at a reduced cost) in the event of a seizure.
Aluminum – These are the most “pushed” kits, used mostly by those who race to win and not just to have fun. They guarantee superior performance compared to cast iron ones, but they cost more and in the event of a seizure they are to be thrown away: the repair would cost more than a new kit.
80 and 90 cm3 – There are also “extreme” tuning kits that bring the displacement to 80 and 90 cm3, used for acceleration races: the performance is remarkable, but requires a bit of experience. These are semi-artisanal productions: the most widespread are those of Stage6, TCR by Cristofolini and TRT Tedeschi.
Warning: by changing the engine size you are no longer in compliance with the Highway Code. The scooter can only be used on the track, never on normal roads.
Cycling
Scooter frames and suspensions are not designed for racing and tracks: the engine position close to the rear wheel is not ideal for the correct balance of the vehicle. To improve the situation a little (without expecting miracles) you need to change the rear shock absorber with a better quality one. There is little to do about the fork, the standard ones are difficult to improve: you have to adapt. For the brakes it is better to replace the pipes with those in metal braid that ensure better performance.
