Information: Original cylinder head, cylinder bored to 60 ccm.
Carburettor jets leaved as original, needle in normal position (as suggested in manual)
The carburettor restricion removed (throttle cylinder shortened by 3 mm). Exhaust port has been widened up by 4mm. Exhaust tube has been shortened
Small sprocket changed to z=17
Max speed 70..72 km/hour.
Fuel consumption 2.5...3 l/100 km at 55-60 km/h