1/2" bore clutch?

[tachwinder]

I have an old 1951 vintage ast iron Briggs engine (it says model 5S on the engine). I acquired this a number of years ago on an old mini bike frame from a salvage yard. I sold the mini bike frame and kept the engine. The engine was much older than the bike it came on. Anyway, I now have a Wizard Trail Horse mini bike which is very light. The original engine is in very poor condition and I am assessing my options as to what to install for an engine--possibly temporarily. I have the small Briggs mentioned above but it has a 1/2" output crank shaft diameter. Does anyone make centrifugal clutches with only 1/2" bore?
Regards,
Terry

 

[minidragbike]

Maybe from a 2 stroke motor? I don't know there size, but they have to be pretty close.

 

[Yellowhand]

I'd use a 3/4" clutch fitted with an adaptor bushing...

Does that 1/2" crank have a keyway or is it threaded?

Is the crank 2-5/16" long?

Is the crank tapped for a retaining screw?...without a retaining screw, the clutch can 'walk' outwards on the shaft during use, eventually snapping the shaft off at the side bearing point.