Poini 133 Racing racing cylinder Vespa

Polini 133 racing cylinder available!

This is a classic one Polini racing cylinder for the Vespa Smallframe Models PV / ET3 / PK / XL / XL2 models, except PK automatic.

This tuning cylinder is the revised version of the legendary 133 Polini and offers a plug & play high durability with a lot of torque.

But the cylinder also offers a lot of potential for ambitious tuning of your Vespa beyond the 20PS. If that's not enough: Polini 152 Big Evo cylinder

Poini 133 Racing racing cylinder Vespa

The main innovation of this "racing version" compared to the classic 133 relates to the cylinder head, which is made of cast aluminum with a high silicon content. In addition, the head has additional cooling fins on the underside. This means that the heat is dissipated much better, both from the cylinder itself and from the head. The compression was also slightly adjusted.

The copper seal not only conducts heat better, it also contributes to a significantly better seal between the cylinder and the head.

The layout of the cylinder is unchanged and is determined by the six transfer ports. The ASSO piston is made of die-cast, which gives it very good durability and low weight.

With a 57 mm bore, 51 ccm with a 130 shaft and an impressive 54 cc with a 138 shaft are available.

Racing cylinder of the K5 in the ESC

The cylinder is used unchanged in the ESC (European Scooter Challenge) in the K5 class very successfully in races and has "put" around 15 hp.

We already had this cylinder, extremely revised, with 30 HP on the test bench!



Instructions Polini 133cc


140.0050 / R | | 1400050R | P1400050R


Fits on these vehicles

This is the original press release from Polini about the cylinder:


RACING GENERATION Polini Motori has revised the popular cylinder kit for the Vespa 125 Primavera ET3. This is now also available as a RACING version with a specially developed cylinder head for better cooling. The cylinder head itself is also available individually. TECHNICAL DATA: The cylinder is made of cast iron with lamellar graphite. As a result, it has a self-lubricating effect and is very resistant to mechanical loads. This reduces the working temperature and prevents possible loss of performance. The cylinder has a 57mm bore and 6 overflow channels. The piston is made of chill cast light metal with a high silicon content and has two “S10” chrome-plated piston rings. The aluminum cylinder head is equipped with two fins, which dissipate the heat better. Cooling and compression ratio are optimized. The new copper seal prevents gas from escaping between the cylinder and cylinder head and facilitates heat exchange.



bgm177 vespa cylinder development

bgm 177 - the new 177 - cylinder for Vespa

In this post we have already introduced you to the new cylinder. Today we give you a little insight into the development of the cylinder. From the beginning of April 2016 the cylinder finally available!

bgm 177 - the development of the Vespa cylinder

Developing a two-stroke cylinder is very exciting.
Countless parameters that have to be taken into account, thousands of test bench runs, repeatedly measured, calculated, tested, thousands of kilometers of road tests ...

Everything to get a cylinder as a finished end product that high-torque and willing to perform is, but also at the same time durable is and uses little fuel.
At the same time, it should offer the broadest possible range of applications for touring riders who simply combine it with series components, as well as for the sporty, ambitious tuner who is more concerned with performance.

Here is a little insight into the test series that were on the daily program for the BGM177.



We have tested a wide variety of solutions for the external shape and design of the overcurrent channels.
We created various duct geometries, control angles and cylinder combustion chambers and compared them both on the road and on the test bench.

BGM177 cylinder test


For some of the tests, in addition to an original Piaggio Sprint, we also used an LML engine housing with original inlet membrane control as a starting point.
The Sprint's motor housing is representative of the very small, original rotary valve inlet of the Largeframe Engines. The rotary valve inlet of a PX125 is only slightly larger than the inlet of the Sprint engines and the control angles of the crankshafts are almost identical. In terms of the expected output, this is the “most unattractive” starting position. Nevertheless, we wanted to know what performance can be expected with these basic requirements or, better yet, which performance can be achieved.

We presented the result on a Sprint engine with the 24mm SI carburetor of the PX200 in comparison to a 12HP 200 engine.

So that you can interpret the graph below a little better, just imagine a normal PX200. Up to approx. 90km / h something like acceleration can still be felt on a standard 200. This speed corresponds to about 5500min? ¹ of the motor. From this speed, the torque of a 200 engine drops so far that it takes some time to reach 100km / h (6000min? ¹). If you now compare these speed points of the blue curve with those of the red curve on the graph, you can see that the BGM177 is still increasing torque in this area. In other words, when the 200 slowly runs out of air, the BGM177 accelerates even further.

BGM177 vs PX200



Since the 125cc engine of the Vespa Sprint with the small rotary valve is too restrictive on the power delivery from a certain power and speed level onwards, we used an LML engine housing for various tests and comparisons. The LML motor housing offers the best prerequisites due to the diaphragm inlet that is already present at the factory and the large overflow channels in the housing. As a result, for example, an inlet that is too small or differently designed overflow channels can have no or only an insignificant influence on tests within a test series.

BGM177_9 023

So on the LML housing you can easily switch between an SI carburetor and a large, adult intake manifold.

We performed the tests in this area with a pre-series cylinder with small duct cutouts in the cylinder base
and started with a piston specially made for this test.

BGM177_9 015

The aim of the game was to find out how much space the piston must allow for the overflow duct due to its design in order to ensure good filling. The piston was manufactured in such a way that the clearance around the piston pin in the area of ​​the ÜS channels could be continuously modified by milling.
We tested each of these intermediate steps on our test bench to find out which shape or which combination works best.

Piston BGM177 V2


The test series below was run on an LML membrane motor with a 24 SI carburetor, BigBox Touring and pistons and ducts that have just been processed in different ways.
At this point in time, the cylinder head was still relatively highly compressed. With the cylinder head in series production, we have reduced the compression somewhat in favor of a broader performance curve.

In its original state, the test piston had the contour of an original PX piston. The piston skirt was closed on the red curve (similar to Piaggio, Polini, Grand Sport, ...)
In the blue curve, the piston has been exposed by a few millimeters in the area around the piston pin. The picture above shows such a piston.
The green curve shows the power curve with partially open overflow channels at the cylinder base and the machined piston. The released area of ​​the channels in the cylinder base corresponds to approx. 80% of the possible channel area that the cylinder can offer.

Comparison of the BGM177 piston and channel

  • RED CURVE: Closed piston skirt
  • BLUE CURVE: Half-open piston skirt
  • GREEN CURVE: Open piston skirt

The BGM177 can therefore be equipped with a gearbox from the 200 series engines without any problems and offers significantly better performance than the large 200 series engine.
The PX125 and PX150 motors were equipped with a gearbox from around 1982 that is almost identical to that of the PX200. With these engines, the primary drive can be extended directly in order to convert the gained power into speed.
The use of a primary gear with 64 teeth would be recommended here. Depending on the desired area of ​​application, the overall reduction can then be adjusted accordingly with the coupling pinion. The primary gear with 64 teeth offers the advantage that the bgm clutch pinions with 22, 23 and 24 teeth can be used.
This offers the possibility of changing the engine from “sporty short for the city (22/64)” to “Autobahn - everything that works (24/64)”.

In the next post we equip our LML test engine with different carburetors and intake manifolds ...


BGM177 the cylinder for Vespa PX

BGM177 - the new cylinder from bgm PRO

Cylinder -bgm PRO 177 cc- Vespa PX125, PX150, Sprint150, GTR125, TS125, Cosa125, Cosa150

Here we want you the new one BGM177 cylinder imagine the starting April 2016 will be available.


First video BGM177 - the 177 cylinder for Vespa

We showed the cylinder for the first time at the Scooterists Meltdown. The new Online Scooter Magazine SLUK interviewed Philipp and created an exclusive video for our new cylinder:

Suitable for all Vespa 125/150 Largeframe Engines with 3 overcurrent channels.
These include:

  • Vespa PX125,
  • Vespa PX150,
  • Sprint 150Veloce,
  • Vespa GTR125,
  • Vespa TS125 and the
  • Cosa 125/150 models.


Powerful and reliable aluminum cylinder

With the BGM177 we provide you with a powerful and reliable companion.
Many ideas have flowed into the design of the cylinder, so that you can use the cylinder in one as possible wide performance range can use.


Like all modern cylinders, the BGM177 is also made of aluminum.
This has the advantage of very good heat dissipation, which benefits durability, consumption and performance.
A cast aluminum piston with two piston rings works in the extremely wear-resistant nickel-silicon-carbide-coated cylinder bore.

BGM177_8 002


Very light piston

Due to the design and the high silicon content in the material, the piston can be held very light at 193 grams with great thermal and mechanical stability.
This benefits the freedom of rotation and smoothness.
The 1mm thick piston rings are made by a well-known manufacturer in Italy who also supplies leading piston manufacturers such as Vertex and Meteor with high-quality piston rings. The slim rings minimize friction and thus increase performance. In addition, they enable the exhaust duct window to be expanded without any problems.
The piston pin has a biconical design, ie it is thinner at the ends than in the middle. This further helps to reduce the weight of the moving masses.

BGM177_8 011

Aluminum cylinder with ceramic coating and large transfer ports

In the cylinder, the large channel surfaces and the large volume of the overflow channels offer the best basic conditions for a broad performance characteristics and a early onset of torque.

The BGM177 can be combined with simple series components such as the original SI20 carburetor and an original exhaust. This means that the BGM177 already offers a significant increase in performance. The modern design of the cylinder helps him too much low consumption values at the same time high torque from the lower speed range.

Cylinders with great tuning potential

If you are looking for more power, the BGM177 offers sufficient potential and options to achieve the Performance with little effort to raise further. The cylinder reacts very well to a larger carburetor and a supporting exhaust system, such as the bgm BigBox Touring Exhaust system.

The overflow channels in the cylinder base can be expanded very easily. The two large overflow channels on the left and right are only covered by a small sprue in this area. These can easily be opened with a small hand milling cutter. Here, either the cylinder can be adapted to an already revised motor housing or the full duct cross-section can be transferred to a motor housing.

CNC milled cylinder head

The CNC-milled cylinder head is with many cooling surfaces and thanks to the clearance in the middle of the cylinder head, as little heat as possible is bound above the combustion chamber.
In the franking there is also a possibility of a Temperature sensor to assemble. The temperature can be reliably tapped this close to the combustion chamber.
The usual methods, in which, for example, a temperature sensor with an adapter ring is mounted under the spark plug or screwed to a cooling fin on the outside using a thread, do not show any useful values. They only allow you to assess how warm the cooling air near the spark plug or how warm the cylinder head is on the outside of the cooling fin - in our opinion, these positions are simply unsuitable for reliably determining a temperature value. Therefore, bgm uses the positioning very close to the combustion chamber.

BGM177_8 016

Combustion chamber for a wide range of services

The combustion chamber geometry is designed for a wide range of performance. The shape of the combustion chamber cap also allows the use of strong resonance exhaust systems with an appropriately adapted pinch edge. On a 57mm stroke with a touring or box exhaust, the pinch edge can be adjusted to 1mm using the enclosed seals.
If the cylinder is operated with a resonance exhaust and a stroke of 60mm, we recommend that you start with the pinch edge at 1,2mm.

Valve timing 57mm

On a motor with a 57mm stroke you will achieve the following values ​​with a pinch edge of 1mm:

  • Compression 10,3: 1
  • Overcurrent angle 118 °
  • Outlet angle 171 °

The large length of the cylinder enables the cylinder head to be centered in the bore of the cylinder with a 4mm thick shoulder. Due to the shoulder, the cylinder head gasket is still perfectly centered even in the event of a stroke change and cannot stand in the combustion chamber. If the stroke is changed to 60mm, the cylinder can also be raised further, depending on the planned motor concept, in order to achieve significantly larger overcurrent angles.

Valve timing 60mm

On a motor with a 60mm stroke, the following values ​​are achieved with a pinch edge of 1mm:

  • Compression 10,8: 1
  • Overcurrent angle 123 °
  • Outlet angle 173 °

The outlet width is 42mm (66%) and therefore offers good conditions for a high-revving engine even with short control angles.

BGM177 vs PX 200 12hp

Plug & Play with a lot of power

Here is a comparison between a BGM177 and a standard Rally200 with 12PS Piaggio cylinder (comparable to a Vespa PX200 GS).

The BGM177 cylinder is unchanged in this attempt and is on a Sprint Veloce engine.
The inlet, crankshaft and ducts in the engine have not been machined.
Only one SI24 carburetor the 200cc model was assembled without adjusting the carburetor pan or the engine housing, as well as with a BGM BigBox Touring combined.

The spraying is very much based on the original 200ccm equipment:
Main air correction nozzle: 160
Mixing tube: BE3
Main jet: 125
Idle nozzle: 55/160
Air filter: standard (without additional holes)

The pre-ignition was set to 19 ° BC. set.

The broad power range (smooth lines) and the high available torque (dotted lines) from idle can already be seen very nicely on this not further optimized engine.


[Table id = 2 /]

In the next article we will then deal with increasing the performance of the cylinder. An LML membrane motor will serve as the basis for this.

Polini cylinder 207cc aluminum Vespa PX 200 Rally 200

Polini cylinder 207cc aluminum Vespa PX 200 Rally 200... more precisely Polini 210cc aluminum cylinder - because the new cylinder has the following data: Bore: 68,10 / stroke 57

Polini presents the new aluminum cylinder for all Piaggio Vespa PX 200 and Rally 200!

The war of faith Malossi 2011 or Polini 207 or Pinasco 213 In the maximum displacement class, the Vespa scooter with 200ccm receives new arguments.

The torque-heavy design of the Polini207 with steam in all situations was loved by many. But as is always the case with love, there are also days when things don't go quite so smoothly in a partnership.
Incorrect carburetor jets, poor ignition setting or other set-up problems quickly led the old Polini cast cylinder to its thermal limits, and in the worst case even beyond.
This ensured the reputation of the eternal piston clamp, which could be counteracted with expert screws.
Now Polini is making life and screwing easier for all of us, and competition tougher for the competition.
The successful design of the Polini 207ccm is now made of high quality aluminum. With a 68.5mm bore and a great piston with two piston rings, for stable guidance and good heat dissipation, a thermally much more stable starting point for tours and race tuning is created.
Whether simply with the Vespa Sito + exhaust , or thick Membrane aspirator and Resonance exhaust system , We are curious what we will experience with the Polini for performance values.
Visit the - one stop scooter shop - and look for the right ingredients for your engine.

We have ordered a pallet and hope that it will be here as soon as possible. We'll keep you up to date!

parmakit cylinder

Parmakit for Vespa at SCOOTER CENTER

We have new tuning cylinders for Vespa scooters in our program.
Parmakit, the legendary tuning company from Italy, is at the start with the following new racing cylinders.
In the product details you can also find some of the portmaps.

Read more