High Performance Valve Springs for the:
•    Yamaha FZR1000 EXUP 1989-1995
•    Yamaha YZF1000R Thunderace 1996-2005
 
Spring Kit includes 12 Intake Springs, 8 Exhaust Springs and 12 Intake Shims.
Compatible with all other stock parts.
 
Intake Valve Spring Specifications:
Installed Height: 34,5mm (with supplied shims)
Seat Pressure: 29lbs / 13,2 Kgf
Open Pressure (8,5mm): 94lbs / 42,7 Kgf
Max. Recommended Lift: 0,335” / 8,5mm

Exhaust Valve Spring Specifications:
Installed Height: 38,5mm (same as stock)
Seat Pressure: 34lbs / 15,6 Kgf
Open Pressure (9mm): 101lbs / 45,7 Kgf
Max. Recommended Lift: 0,355” / 9,0mm

ABUSO Valve Springs are ideal for modified engines providing higher seat and open pressures while allowing for more valve lift. This ensures better valve control when using more aggressive camshaft profiles and increased RPM and valve lift.

ABUSO Springs are made from Super Clean oil-tempered Chrome Silicon Vanadium Steel Alloy sourced from Japan, especially intended for the manufacture of valve springs requiring very high fatigue properties. Fatigue resistance is further improved by multistage heat treatment and shot peening.
Our springs are Progressive Wound to optimize spring dynamics and avoid harmonic resonance that can lead to valve float and premature valvetrain wear.
 
We also have Stainless Steel valves, Titanium Retainers and Bronze Valve Guides for the Yamaha FZR 1000 EXUP and YZF 1000R Thunderace.