Yoshimura Camshaft ST-1 – GSX1100S / GSX750S Katana

Refined from within.

The Yoshimura ST-1 camshaft is built to enhance response and overall engine performance, bringing a sharper, more controlled feel to the air-cooled Katana platform.

Lightweight construction and precision finishing reduce internal resistance—unlocking smoother power and improved throttle response.

Fitment
• GSX1100S Katana
• GSX750S Katana
(Engine codes: GS110X / 75X / U713)

Specifications
• Type: ST-1
• Max Lift: IN 8.25mm / EX 8.25mm
• Duration (1mm): IN 245° / EX 245°
• Tappet Clearance: IN 0.15mm / EX 0.15mm

Details
• Lightweight hollow cam construction (~20% weight reduction)
• Barrel polished surface for reduced friction
• Improved durability and efficiency

Performance
• Faster throttle response
• Reduced rotational mass
• Smoother, more efficient power delivery

Important
• No tachometer gear (requires electric conversion)
• Bolt-on installation possible
• Valve timing adjustment recommended for optimal performance

Notes
• Minor variations may occur due to manufacturing
• Instructions (if included) may be in Japanese

Precision inside the engine.