Vee Two recommends that piston to valve clearance always be checked.
Opening and Closing Figures at 0.5mm Lift
Inlet Opening 42 degrees B.T.D.C
Inlet Closing 45 degrees A.B.D.C
Exhaust Opening 60 degrees B.B.D.C
Exhaust Closing 26 degrees A.T.D.C
Maximum Lift at Valve