Precision Valvetrain Calibration
Motorcycle Valve Clearance & Shim Calculator
Factory cold intake and exhaust valve lash clearances, shim diameters, and an interactive shim replacement calculator for precision valvetrain adjustments.
Yamaha YZF-R6Shop 7.48 mm Shim Kits →
Factory Cold Valve Clearances
Intake Valves (Cold)Target: 0.15 mm
0.10 - 0.20 mm
Imperial: 0.004 - 0.008 in
Exhaust Valves (Cold)Target: 0.25 mm
0.20 - 0.30 mm
Imperial: 0.008 - 0.012 in
Shim Outer Diameter:7.48 mm
Feeler Gauge Spec:Angled stainless steel feeler gauge (cold engine ≤ 35°C / 95°F)
Timing Mark Ref:Align crankshaft TDC mark with engine timing index pointer
Precision Engine Math
Replacement Shim Size Calculator
Formula: New Shim = Current Shim + (Measured Clearance - Target Clearance)
Enter measured feeler gauge thickness and current shim reading (micrometer measured) to calculate the precise replacement shim.
Measurement Rule: Always measure valve clearances with the engine cold (below 35°C / 95°F). Never force a thick feeler gauge blade; feel for light drag without bending the blade.