Inner diameter: 19mm( if you need 20mm or 16mm,please you contact seller !)
Width of keyway: 4.7mm
Slot number:10 Tooth
Brand New Auto Clutch
Centrifugal Clutch, 11 tooth for a 420 chain
Clutch engagement speed is around 1900-2100 rpm
Fit For 168,152 use the same gasoline engine