BGM PRO 177CC CYLINDER FOR VESPA PX125/150 (ALSO WITH ELECTRIC STARTER)

New version of the proven BGM177 cylinder for Vespa PX125/150. Now also suitable for vehicles with electric starter.

EVERYDAY PERFORMANCE BOOST
The BGM177 cylinder is a very powerful, durable, and fully everyday-compatible conversion cylinder. It covers a very wide range of applications. Simply by replacing the cylinder, the performance of the 125cc standard engine can already be more than doubled, while wonderfully surfing on the large torque crankshaft. Likewise, the exact same cylinder can transform the engine into a beast with over 20PS when it finds the appropriate environment (carburetor, exhaust, crankshaft). Thus, the cylinder offers beginners a perfect basis to expand this further as needed.

The BGM PRO 177 replaces the original cylinder, and the conversion can be easily and reversibly revised if necessary. With its large displacement of 177ccm, the BGM PRO 177 always offers a confident and relaxed riding experience. The engine runs powerfully like a 200cc machine, but is more responsive while maintaining exactly the same reliability and longevity. It achieves this by operating in the same speed range as a standard engine. Low consumption values and the associated high range are another bonus of the BGM PRO 177 cylinder. The cylinder is designed to be fully compatible with all standard components. The only adjustment made is a change to the carburetor jetting and a spark plug with an adjusted heat range.

FEATURES
The BGM PRO 177 cylinder is a hard ceramic-coated aluminum cylinder with a 63mm bore. The coating (Nickel-Silicon Carbide) ensures an extremely hard and durable running surface. The piston features a high silicon content. This gives it a lower thermal expansion, is more wear-resistant and thermally very stable. Two 1mm thick piston rings minimize friction and thus increase performance and speed resistance.

• Cylinder material: Aluminum

• Running surface: coated with Nickel-Silicon Carbide

• Bore: Ø 63mm

• Displacement 57/60mm stroke: 177/187 ccm

• Piston: Cast piston with high silicon content and two 1mm steel piston rings

• Recommended squish clearance: 0.8- 1.2mm

CYLINDER HEAD
The cylinder head is CNC milled from solid stock. The combustion chamber is recessed 4mm into the cylinder for perfect centering. In addition, this greatly facilitates the adjustment of the squish clearance and ensures a reliable seal. In the middle, there is a thread for mounting a temperature sensor. The compression ratio was deliberately chosen to be low at 10.3:1. For this reason, the squish clearance can be lower than with comparable other cylinders.

FURTHER TUNING
The cylinder kit is designed as a plug 'n play solution. The cylinder offers, with full reliability, however, still a lot of potential upwards. With a 24mm carburetor of the 200cc models and a BGM Big Box Touring exhaust, the performance is already around 15 PS and the torque is 17 - 19Nm at the rear wheel. The BGM PRO 177 reacts very gratefully to all performance-enhancing measures such as:

• A suitable exhaust system (BGM BigBox Touring (BGM1011TR), Polini Box (P2002018))

• A larger carburetor (BGM PRO Faster Flow SI24 (BGM8570))

• Crankshafts with extended intake timing (BGM031120G) and/or more stroke (BGM031121G)

• An optimized flywheel (BGM8025RT)

• Optimizations on the intake manifold (enlarging the intake channel)

• Enlargement of the transfer port surfaces in the cylinder foot gasket surface as well as in the engine housing (The transfer ports at the cylinder foot have a spout. This means that the channels on the cylinder match those on the engine housing. The spout can be easily removed to utilize the complete cross-section of the channels)

MORE DISPLACEMENT AND PERFORMANCE
The cylinder is already prepared at the factory to be used with a crankshaft with a larger crankshaft stroke (60mm instead of 57mm as standard). This increases the displacement to a proud 187ccm and the performance-determining timing angles of the ports are enlarged. With corresponding crankshafts and further modifications to the engine, the cylinder can also be used without any problems with an even larger stroke (up to 64mm, see crankshafts KINGWELLE). With this, it reaches the full 200cc, but requires a membrane intake due to the necessary crankshaft (e.g. from MRP Racing 3331680 or 3331682).

IGNITION
Due to the optimized CNC cylinder head with tightly toleranced squish clearance, the BGM PRO 177 cylinder is already very efficient and powerful. The standard ignition components on the Vespa PX models up to Bj. 2011 are therefore also ideal for continuous operation. Special ignition modules or a variable ignition timing are therefore not necessary for high performance and reliability. A simple static ignition setting to 19° BTDC is recommended, but the cylinder can easily be operated with the 18° ignition advance, as it is set ex works on the PX125E models. Models from 2011 onwards use ignition components from China that do not allow very high speeds. Here, the ignition baseplate, the flywheel and the CDI can be upgraded to the old, better standard. We also offer a complete set (BGM666PXL). However, this eliminates the possibility of using an electric starter (the flywheel does not have a gear tooth for the E-starter).

TIMING ANGLES

• 57mm stroke: Transfer 118°, Exhaust 171° (with foot gasket 0.2mm, no head gasket)

• 60mm stroke: Transfer 123°, Exhaust 173° (with foot gasket 0.2mm, head spacer 1,5mm)

• (Head spacer for 60mm stroke not included, optional available, see accessories)

TRANSMISSION
Many customers extend the gearing even in low performance stages in order to better utilize the newly gained power of the engine. This is done by simply replacing the clutch pinion. This is relatively easy to reach after dismantling the rear wheel and the clutch cover behind it. Alternatively, a reinforced clutch type can also be switched to directly (see accessories). After that, the gears can be accelerated out much further and the achievable top speed is increased. The engine has so much power that the acceleration is usually also better because less or faster shifting is necessary.

Generally, the gearing can be longer than usual in the 177cc class due to the high torque. If a touring-oriented exhaust with early support is used (BigBox Touring, Polini Original Box), a clutch pinion with at least 23 teeth should be used on a PX125. We specifically lead these for the original primary gear with 68 teeth (see accessories). Engines with long-stroke crankshafts also easily pull a 24/65 gearing on PX125 transmissions.

CONCLUSION
Universally usable plug 'n play cylinder kit with early performance, wide speed band, reliability like an original cylinder, low consumption values and thus an unbeatable price-performance ratio!

About the manufacturer BGM

BGM is a leading brand for high-quality spare parts and accessories for scooters, motorcycles and classic Vespa models, which stands for quality, precision and innovation. With a uncompromising „Made in Germany“-philosophy, BGM develops durable products in cooperation with leading engineers and under strict quality controls. Whether restoring vintage vehicles or tuning modern scooters – BGM is the first choice for demanding drivers. Thanks to first-class workmanship and a wide range, BGM offers ideal solutions for performance, everyday use and individuality.