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Crankshaft Vespa PX80 BGM031080G (3)

Crankshaft Vespa PX80

Many of you still know and may have discovered your love for the Vespa on this scooter:

The Vespa PX80, which was built by Piaggio only for the German market.

80cc - the German way

With the fall of the old regulation valid in Germany until 14.02.1996/80/80, 80ccm up to a maximum of 80km / h, the sale of the PXXNUMX in Germany was also discontinued. Unfortunately, the spare parts supply from Piaggio became very scarce. For a long time there was no alternative to the expensive, original and difficult to find Piaggio PXXNUMX crankshaft.

In the meantime, however, the PX80 has also stood out from the shadows behind the PX200, which is favored in Germany, and there is a loyal fan base for the smallest motor from the PX family.

Vespa PX80 tuning

With the appropriate components, however, the PX80 can again experience an enchanting second or third spring and catch up with the performance of its big sister.

Well-known friends are here “The 139er” from Malossi and “The 135” by Diffusione Ricambi, DR for short.

While Pinasco tried to add a shovel with the 149 aluminum cylinder, Polini never tried the PX80.

Vespa PX80 crankshaft - the weak point

Regardless of which cylinder was driving the unit of the PX80, the original crankshaft went the usual way: by losing the thrust washers and the resulting death of the lower connecting rod bearing, it quit its service - good advice was expensive.

The solution: our Vespa PX80 crankshaft from bgm PRO

You will learn from experience, which is why we have the easy-to-turn PX80 with our bgm PRO Crankshaft for Vespa PX80 donated a set of sturdy thrust washers.

With the bgm crankshaft there is finally a suitable replacement for the PX miniature motor.
With the bgm standard crankshaft with 48mm stroke, there is only a very slightly longer intake time.

Other crankshaft manufacturers design a much too large opening angle for the PX80, the result is that the cylinders with the small control angles in connection with the small inlet provided by the "anti-tuning bores" no longer run usefully in the lower speed range. The tunability of such motors also suffers due to the large opening angle.

Also available as a long stroke shaft Vespa PX80

So that screwing on the PX80 is fun again, we also have a "Long stroke version”Placed on the bgm crankshaft.

With 51mm stroke On the small engine, other performance values ​​can be achieved and the existing cylinders benefit from the increased control angles.

 

Order crankshaft for Vespa PX80 here

Comparison of long-stroke and standard shaft

Here is a quick comparison when using the different cylinders on 48mm and 51mm stroke.

Series stroke 48mm Outlet angle ° Overcurrent angle ° Advance °
DR135 155 115 20
Malossi 139 182 120 31
SC conversion cylinder 125ccm 155 110 22,5
Long stroke 51mm Outlet angle ° Overcurrent angle ° Advance °
DR135 + head gasket 1,5mm 158 121 18,5
DR135 head gasket 1,5mm (+ 2mm outlet height) 168 121 23,5
Malossi 139 head gasket 1,5mm 184 126 29
Malossi 139 head gasket 2,0mm (foot -0,5mm) 182 124 29
SC conversion cylinder 125ccm head gasket 1,5mm 158 117 20,5
SC conversion cylinder 125ccm head gasket 1,5mm (+ 2mm outlet height) 168 117 25,5

 

Tip: Pay attention to the correct translation

If the PX80 is equipped with a larger cylinder, the Primary reduction be changed.

The PX80 has the shortest version with 20/68 teeth. For the original clutch with 6 springs and a diameter of 108mm Clutch pinion available with 21, 22 and 23 teeth.

A clutch for life:

Alternatively, the entire clutch can be exchanged. Also the BGM Superstrong Fits into the PX80 after a few small changes and can be operated with the primary wheel of the 80s. Here, too, there are variants with 20, 21, 22 and 23 Teeth.

Vespa clutch bgm PRO Superstrong MADE IN GERMANY Cosa clutch Vespa PX

Vespa PX80 conversion tuning

Easily convert the Vespa PX80 to 125ccm - this is how it works:

The vehicle prices for the Vespa PX models have been rising for years. The cheapest models are still the Vespa PX 80 / PX80 Lusso. The 80s Vespas have the least performance and are rated the most expensive by insurance companies. When converting to 135ccm or 139ccm, the scooter can no longer be driven with the 125cc driver's license. Here we show you how you can easily convert a PX80 to a PX125 without having to work on the crankshaft or the gearbox:

Cylinder -SCOOTER CENTER Conversion cylinder Vespa PX80 to 125 cc- Vespa PX80 / PX80 Elestart

TÜV registration possible! TIP: Suitable for Elestart engines without modifications!

Advantages of retrofitting:

  • more performance and safety reserves in road traffic
  • less consumption approx. 20% according to customer experience
  • Can be driven with an old 125 driver's license
  • cheaper insurance
  • same durability
  • easy installation

We offer you a complete cylinder kit to bring every PX80 plug & play to 125ccm displacement.
If the kit is registered with the TÜV as an individual approval, you can use the significantly lower insurance rates of the 125cc models benefit. All you have to do is change the cylinder, including the piston and head, the short motor remains unopened!

More performance - less consumption

Originally the 80ccm engine has about 5HP on the rear wheel. With our conversion cylinder, the performance increases by a whopping 60% to a remarkable 8PS and that with extreme reliability. This means that the performance of the cylinder is already in the range of a 135 DR. In this diagram you can see a direct comparison between a 135 DR tuning cylinder (blue curve) and the SCK 125cc conversion cylinder (red curve). In connection with an extended transmission (possible by simply changing the clutch pinion to 22 teeth), the top speed is also significantly increased. The significantly wider torque curve means that the gears no longer have to be fully accelerated, and consumption is reduced.

 

Performance Graph 125cc Conversion Kit vs DR135

Performance Graph 125cc Conversion Kit vs DR135

Are the brakes and frame overloaded?

No, with the conversion kit you are on the safe side - the Vespa PX80 has the identical brake and chassis components like a Vespa PX125 and even a Vespa PX200, which is / was available from the factory with 12PS.

Durability of the cylinder

The durability is at least as good as the original cylinder: almost indestructible. Two, with prototypes of the Scooter Center In 2011, vehicles equipped with conversion cylinders were on the road for several thousand kilometers without problems or breakdowns. The drivers are from the Performance and low consumption simply enthusiastic.

5 star rating of Bernd:

"installation was easy, it only took 1 hour has run for about 300 km without problems with a 105 hd now drive in 3rd gear with half throttle where I used to have to take 2nd gear with full throttle fuel consumption has decreased by about 20% this cylinder set was the best investment in my vesp so far"
Complete cylinder kit to bring every PX80 plug & play to 125ccm displacement. If the kit is registered with the TÜV as an individual approval, you can benefit from the significantly lower insurance rates of the 125cc models. All you have to do is change the cylinder, including the piston and head, the short motor remains unopened!

Rating in Scooter Center Online-Shop

Recommended motor settings:

optional:

 

Video about the Vespa PX80 - PX125 conversion cylinder

 

TÜV certificate and Piaggio approval

Unfortunately, it is currently not possible to deliver this cylinder with a TÜV certificate.
The technical and formal hurdles for such an expert opinion are now so high that it is not economically feasible (the selling price of the cylinder would then be much too high).

The Vespa PX80 has the same brake and chassis components as a Vespa PX125 and even a Vespa PX200!
It is therefore possible to have one official approval from Piaggio you can get it Request online HERE. This is made specific to the chassis number, so a mere copy is not enough.
The TÜV then has the working document in black and white that the PX80 also has the same brake and chassis components as a PX125 (or even PX200). Equipped with this, the engine that has been converted with our cylinder can then be demonstrated. The official Piaggio document usually opens doors and gates.

 

Possible tuning measures

"Stage 1"
If you want to elicit more power from the cylinder, you can turn the cylinder by approx. 1mm on the head sealing surface.
The crush dimension (distance piston to cylinder head) should then be approx. 1,1mm at the narrowest point. Simply push 2mm solder through the spark plug hole into the edge area of ​​the combustion chamber and turn the crankshaft.

"Stage 2"
If you want significantly more power and torque, you can easily achieve this with the original cylinder head of the PX80. Due to the smaller combustion chamber, the compression increases again significantly and the power / torque increases by at least 1PS / 1NM. For this, however, the distance between the cylinder head and piston should also be checked (at least 0,8mm) to avoid mechanical damage. The sealing surface of the cylinder head protrudes into the combustion chamber of the cylinder. This is only an optical shortcoming, technically this solution is completely unproblematic. .

"Stage 3"
Furthermore, the outlet window can be widened 1mm on each side. With these measures, the cylinder is already scratching the 10PS brand. With a lighter fan wheel we already have over 11PS and 13Nm is reached (see second diagram). The driving behavior is therefore very similar to an original Vespa T5. Individual adjustments to the jets and the ignition setting are then of course mandatory.

 

Vespa PX80 conversion tuning

 

Vespa PX80 cylinder Malossi 139ccm tuning performance km-h

Vespa PX 80 with Malossi 139ccm cylinder

In many cases, the TüV requires a performance report to enter changes to the engine.

Next to the 135cc DR cylinder is the  Malossi cylinder with 139ccm one of the most popular cylinders to help the little PX on the jumps. So also in this case, our customer Timur needs such a diagram for the demonstration and entries with the TüV.

Vespa PX80 tuning Malossi 139 cylinders

Performance graphs cylinder MALOSSI 139 cc Vespa PX80

When measuring according to DIN on the Amerschläger P4 test bench, we have to enter the key data of your engine in the diagram so that the tester can correctly assign the diagram to the vehicle. All scooters with gear shift and four gears are usually measured in third gear. This information is also noted in the diagram.

 

Vespa PX80 cylinder Malossi 139 tuning speed versus power       So that the changed maximum speed can also be entered during the test, we carry out a performance versus speed run. Here all available aisles are simply extended.