coped steel bungs are 1" diameter and are drilled and tapped all the way through with 5/16"-18 thread

You thread it on then tighten the bolt and give it a smart rap with a hammer to pull the clutch hub from it's taper

Also fits 500 c

This heritage is reflected in our elevated front mount design with a shallow tunnel that sits high on the frame's backbone

1/4 inch BSP Petcock Fuel Valve Reserve For Triumph 650 750 Norton 750 850 Fork Tube Diameter_33MM coped steel bungs are 1"This petcock features the proper 1 4 inch BSP (British Standard Parallel) threads for Triumph, BSA and Norton motorcycles, as well as any others with the BSP threads. This 'flag' style petcock is original equipment for Triumph 750cc models such as T140 and TR7, as well as Norton 750 and 850 cc motorcycles. Replacement for OEM # 60 4512