Malossi Contra Spring (yellow) – stable variator tuning for your Yamaha X-Max

An often underestimated key to truly clean variator tuning is the contra spring in the driven converter unit. This is exactly where this Malossi contra spring comes in: it sits in the driven converter unit and generates the necessary counter pressure on the rear converter (Speed Drive / Torque Drive). This directly influences the shifting behavior of the variator – especially important if you want to get smooth, controlled acceleration out of your Yamaha X-Max 300.

Typical symptoms where a new variator spring makes sense: the V-belt slips slightly, the engine speed fluctuates during acceleration, or the engine does not reach its power RPM despite roller set tuning. After installation: variator rollers and possibly clutch springs should be readjusted so that the overall system works together perfectly again – especially for setups for the Yamaha X-Max 300 or the Tech-Max.

Technical Data / Details

• Manufacturer: Malossi
• Type: Contra spring / variator spring for the converter unit (driven pulley)
• Color: Yellow
• Outer Ø: 67 mm
• Length: 120 mm
• Wire thickness: Ø 5 mm
• Spring rate: 6.25k
• OEM / Comparison numbers: 2918425.Y0, 2918425Y0

Advantages / Features

• Optimizes the shifting behavior of the variator through defined counter pressure
• Helps with belt slip, RPM fluctuations, and missing power RPM despite roller tuning
• Ideal for a clean tuning on the Yamaha X-Max 300 (including Tech-Max variants)
• After installation: readjust rollers & possibly clutch springs for maximum performance

Compatibility / Vehicles

• Yamaha X-Max 300 (E4, Year 2017-)
• Yamaha MWD 300 Tricity (2020–2024)
• Yamaha YP 250 R X-Max (2014)
• Yamaha X-Max 300 Tech-Max 300 (2020–2024)

Why Malossi?

Malossi contra springs for the converter unit are made of silicon steel – this ensures high strength even under extreme loads and strong temperature fluctuations. This is made possible by a high carbon content and a special heat treatment of the surface. Additionally, Malossi variator springs are dynamically balanced and are developed for each specific application – that is exactly what makes them so reliable for your variator setup.