Description
BIG DEPS 4 cylinder for Piaggio mopeds
75cc tuning cylinder Malossi MHR BIG DEPS 4 for Piaggio Ciao / Piaggio Si.
The BIG DEPS 4 is the most powerful cylinder from Malossi for Piaggio mopeds. It can only be used in combination with the Malossi MP-One crankcase, with 4 studs (as opposed to 3 on the original crankcase).
This Malossi innovation allows optimization of the transfer ports and a bridged exhaust design. Malossi is the only manufacturer to offer this type of exhaust for Piaggio Ciao, Si ..etc. in 2022.
The 4-bolt flange is designed to be fitted with the Malossi Too Bad exhaust, which in turn is perfectly tailored to the Big D.E.P.S. cylinder.
To exploit the full potential of this cylinder kit, you will need a Malossi MP-One crankcase, a Malossi Power ignition, an Overrange CVT kit, a PHBG 21mm carburetor, a Malossi Too Bad exhaust and, of course, a few hours to set up your new racing moped.
Technical data Big DEPS:
- Aluminum cylinder with Nikasil coating, 6 transfer ports, bridged exhaust
- 47 mm 1-ring piston with 12 mm piston pin
- High-compression cylinder head with centering and excellent heat conduction
- High-quality gaskets
- Exhaust flange with 4 screws
- 4 cylinder studs
- Recommended squish: 075 - 0.80 mm
- Compression ratio: 1:13.95
- Displacement: 74.6 ccm
- Can only be fitted in combination with a Malossi MP-One crankcase
- For Piaggio Ciao, Si, Bravo, Boss, Boxer, Grillo and Italjet Pack
Malossi MHR
The MHR series from Malossi is generally available in 3 categories for the most popular models:
The 3 model series differ in terms of performance and competitiveness. The MHR Team series includes the top-of-the-line models with outstanding performance for racing. The MHR Racing is in the middle, and the MHR Replica adopts the basic features of the higher versions, with the emphasis on reliability for everyday use rather than maximum performance for the race track.
How to Install a cylinder on a scooter, motorcycle or moped
The cylinder or cylinder kit is the heart of the engine on scooters, motorcycles and mopeds. It consists of a cylinder, a piston with piston ring(s), a cylinder head and gaskets needed for installation.
The service life of a cylinder depends on whether it has been fitted correctly.

Tuning Level: High End racing
We categorize our products into different performance levels Original, Sport, Racing and High End , so that our customers can choose the right parts for their setup. It is really important to combine parts that belong to the same tuning level, this is especially true for cylinders, crankshafts and exhausts.
High End Racing products are exclusively designed for racing and should only be handled by tuning pros with the appropriate technical know-how. High-end racing parts often require modifications or machining of certain elements to accommodate the often larger components (larger crank webs, larger intake, etc.). Whether you stick with 50cc or increase the displacement, high-end racing parts offer much higher performance than the original parts and are the most powerful tuning parts.
Note: To ensure the reliability of the engine, it is important that the parts are compatible and that you do regular maintenance on your two-wheeler.
Aluminium cylinders
Aluminium cylinders are more powerful than cast iron cylinders, but require more regular maintenance and must be combined with different components such as a reinforced crankshaft and a larger carburetor.
How to run in an aluminium cylinder?
Aluminium cylinders should be run in for about 200 kilometers , and you should use a fully synthetic engine oil.
Note: To ensure optimum performance and reliability, it is advisable to measure the squish clearance. Just have a look at our tutorial How to adjust squish clearance.