Minarelli 40mm Piston Kit - 10mm or 12mm Wrist Pin

40mm Piston Kit for Minarelli Engines and Yamaha Scooters

This piston kit suits Minarelli 1PE40QMB and 40QMB engines, which are typically used in a range of 50cc scooters. Everything required for a full replacement is included, so fitting it is fairly simple. It falls under our Minarelli 50cc / Yamaha Jog scooter parts range and plays a key role in keeping the engine running well. You can pick a 10mm or 12mm wrist pin so it lines up with your engine setup.

Everything Included in the Kit

The kit comes with a piston, wrist pin, piston rings, and two circlips, covering a complete rebuild. These parts are meant to work together for dependable engine operation. The piston measures 40mm across the bore and 50mm in height, and it serves as a direct OEM-style replacement for the original piston.

Which Engines It Works With

This piston is made for Yamaha Jog-based 50cc two-stroke engines as well as a number of Chinese 40QMB clone engines. It suits riders who want to restore power or deal with worn parts in their scooter engine. Swapping in a new piston when the old one shows wear or damage helps keep the engine in good overall condition.

Specifications

• Piston Diameter: 40mm
• Piston Height: 50mm
• Piston Pin: 10mm or 12mm (choose your variant)
• Includes: piston, pin, rings, and 2 circlips
• Engine Compatibility: Minarelli 1PE40QMB / 40QMB 50cc 2-stroke
• Fits: Minarelli 1PE40QMB (40QMB) 50cc 2-stroke engines, including Yamaha Jog-style and Chinese 40QMB clones

Fitment

Fits:

• Minarelli 1PE40QMB (40QMB) 50cc 2-stroke engine
• Yamaha Jog 50
• Yamaha BWS 50
• Chinese 40QMB-based 50cc 2-stroke scooters

How to choose: Pick the 10mm or 12mm pin size that suits your engine. Each size is listed as a separate variant, identified by the SKU suffix -10 or -12.

Browse related parts: Minarelli 50cc / Yamaha Jog Parts · Scooter Pistons & Piston Rings · Scooter Bolts, Screws & Hardware · Scooter Parts