Multivar 2000
Piaggio 51 9019 is the basis of both kits. Includes 7.2 g rollers and a white contra spring. Install according to instructions and tune to engine behaviour.
MV21 selection guide · Piaggio 2T AC
Your Piaggio.
The next level.
Air-cooled Zip? Start with the exact carburettor version and build a 50 or 70 cm³ Sport setup with matched parts.
Air coolingCarburetted engineProducts from our store
Build my setup 
PIAGGIO 2T AC50 cm³ base. Matched conversion.
01
The right starting point first
Piaggio 2T. Which version?
Here we start with air-cooled Zip 2T from 2000 to 2015. Zip SP, 4T and iGet are not included in this selection.
Check the exact version using documents and frame code. This is not automatic selection for every Piaggio with a similar name.
Retain the complete cooling shroud, fan and clean cooling fins. An LC cylinder does not fit an air-cooled engine. Euro 4 and fuel-injection conversions are assessed separately.
02
How far shall we go?
Two starting points. One system.
Retain the existing 50 cm³ cylinder or move to Malossi Sport with suitable intake and transmission tuning. See each part’s price and ordering availability below.
The total includes one of each listed base part. Installation, tuning and extra materials are excluded. “70” is the Sport class name; the selected Ø47 mm cylinders have a displacement of 68.2 cm³.
Cylinder + exhaust
Malossi Sport and Team 4 are selected for a moderate Sport project. LC and AC cylinders are not interchangeable.
Intake connections
CP 19, Ø25 mm Piaggio manifold and Ø46 mm sports filter. A different CP version is selected for the airbox.
Piaggio drivetrain
Multivar 51 9019, 19×15.5 mm rollers and a model-specific belt. Aerox parts are not transferred here.
03
From idea to parts
Your setup, part by part.
70 cm³ Sport with a 19 mm carburettor and open sports filter. Choose add-ons and mark only the exact parts you already have.
For a racing engine, plan the whole build first.
Simply fitting a sports cylinder is not enough here. Before choosing parts, we need to know the existing crankshaft, stroke and conrod length, piston pin, intended cylinder, carburettor and budget.
Then match the intake, exhaust, ignition, bearings, cooling and CVT. We do not yet offer an automatically approved racing kit here.
Discuss your project with MV21 ↗Before selecting the kit
Check the crankshaft, bearings, oil seals and cooling before installation. If there is play or wear, address it first. This selection does not confirm the condition of your existing engine.
This guide’s 70 cm³ Sport project is intended for a closed track. Physical part compatibility does not mean the entire conversion is approved for road use. Even a 50 cm³ exhaust requires checking the exact vehicle type approval and installation conditions.
04
Piaggio drivetrain
CVT is a system.
Match rollers, clutch and belt to the selected variator and exact engine. These kits retain standard transmission dimensions.
19×15.5 mm
This is the roller size for the selected Multivar. The extra 5 g set is a tuning option, not a universal recommendation for every 70 cm³ engine.
Clutch · 107 mm
Malossi Fly Clutch 52 8797. Check bell inner diameter and friction surface. If the existing clutch works properly, replacement is optional.
Zip ≠ NRG
For Zip 2T / SP, choose 6111246. NRG / Runner uses 6116889. The guide switches belts by model; they are not for an Over Range conversion.
In what order should I tune the drivetrain?
First sort out the engine and inspect belt, rollers and bell. Then tune the variator with rollers and the contra spring. Small clutch springs determine engagement. Spring colours are not a universal stiffness standard across brands.
05
A spark at the right moment
Ignition and the right spark plug.
70 cm³ Sport alone does not require ignition replacement. A healthy standard system is the starting point; CDI and inner rotor are planned around the engine’s exact electrical system.
System version first
Compare the existing CDI / coil, stator, connections and immobiliser. Do not interchange 2T carburettor, PureJet and 4T electronics just because the casing says Piaggio.
Lighting and cooling too
For an inner rotor, check taper, mounting, timing and lighting supply. AC engines also need fan drive retained. Unverified ignition is not automatically added to this starter kit.
The plug follows the cylinder head.
By engine version
Choose according to the exact model manual and ignition requirements. This guide does not assign one plug code to all original Piaggio heads.
NGK BR8EIX
Malossi 7311667 instructions specify Denso IW24 for Sport use. Denso’s cross-reference lists NGK BR8EIX as equivalent. M14×1.25 and 19 mm reach, resistor type.
Match plug heat range and gap to the manufacturer’s instructions, load and fitted ignition. Do not automatically choose a racing plug or original-head plug based on the Sport kit.
Tuning is part of the setup
What not to overlook.
Installing parts is the beginning. Recheck the settings after changing the cylinder, intake or exhaust.
Sports filter: what changes?
An open filter is a valid option. It must fit the carburettor connection and clear the bodywork even when the engine and suspension move. Adjust the fuel mixture after changing it. Louder intake noise alone is not measured additional power.
In this selection, Polini 203.0097 is paired with CP 201.1901 (Ø46 mm). For the airbox option, we use the different CP 201.1902 (Ø34 mm). Plan regular maintenance and protection from direct water spray for the sports filter.
Which jet and rollers are right?
There is no single universal number for this kit. It depends on the exhaust, filter, engine condition and conditions of use. Choose jets made for your CP carburettor series; follow the manufacturer’s tuning instructions and avoid an excessively lean mixture.
The rollers supplied with the variator are a starting point. Match roller weight and springs to the engine’s operating range without making several unverified changes at once.
Does 70 cm³ immediately require a different crankshaft?
You cannot decide from “70 cc” on the box alone. The specific cylinder, revs, piston pin, stroke and existing crankshaft condition matter. The selected Malossi Sport cylinders are designed for a 12 mm pin and 39.3 mm stroke. This kit is not automatically compatible with a different stroke or conrod.
If wear or previous modifications are unknown, inspect the engine first. For a racing kit, plan the crankshaft, bearings and ignition together with the cylinder.
What else is not included in the parts total?
Installation and tuning, required jets, a spark plug unless selected separately, coolant for liquid-cooled engines and other materials. Check the throttle cable end and free play, choke cable routing, oil and vacuum connections on the scooter itself.
When fitting the CVT, follow the variator instructions, including the specified spacers. Add oil seals, bearings and a crankshaft after inspecting their condition. Do not neglect the brakes and tyres needed for riding.
Can I keep the oil pump?
Check this against the cylinder manufacturer’s instructions and the existing system’s condition. An oil connection on the carburettor alone does not confirm sufficient pump delivery for the conversion. We do not give one mixture ratio for all engines.
How was the parts selection checked?
We compared model fitment using the store’s internal parts finder and Polini and Malossi catalogues. Carburettor, manifold and filter connections were compared by size. This is a parts selection with installation conditions, not a complete engine tested on a dyno.
LC and AC cylinders have separate codes. Choose the belt for the specific model. Malossi VL13 is an optional extra, not added by default; it was unavailable to order when checked. PureJet, 4T and Euro 4 versions are not part of this first kit list.
More guides to come
Next platforms.
Horizontal Peugeot 2TLudix and later Speedfight versionsOther AM6 modelsSeparate geared-engine guideOther Derbi D50B0 versionsSeparate fitment selection
Catalogues and installation instructions · Piaggio
- Malossi Multivar 51 9019, models and contents ↗
- Malossi Sport cylinders 31 7353 / 31 6926, specifications and plugs ↗
- Polini Team 4 200.0407, fitment and homologation limitation ↗
- Polini 215.0423 manifold connections ↗
- Polini CP carburettor connections ↗
- Polini CP tuning ↗
- Zip belt 6111246 ↗
- NRG / Runner belt 6116889 ↗
- Malossi VL13 model list ↗
- Denso IW24 and NGK BR8EIX cross-reference chart ↗
