OutdoorKing Repair Forum Forums Collectors Corner Cylinder Scott Bonnar clutch 33 - Villiers Vs Briggs and Stratton

I picked up an early SB 33 #000303 with a Villiers two stroke engine (part thereof). The metal-to-metal clutches looked the same on the outside of both units but on disassembly of the clutch on the Villiers `s drive shaft, I discovered that the locking system (engine shaft to clutch) was completely different. (see photos).

The B and S engine output shaft is locked on to the clutch housing with a compression sleeve and lock nut on the outside of the clutch housing whereas the Villiers engine output shaft is cone shaped with a thread on its end*. This shaft goes through the clutch housing and is locked in place with a spring washer and a nut on the inside of the clutch housing (under the engine clutch thrust race). The rest of the clutch system is then exactly the same as the B and S Scott Bonnar 33.

* Same output shaft used on the Villiers powered BonMow 19 direct drive (no clutch).

I now have three (3) different metal to metal clutch assemblies.

(a) 3/4 inch engine output shaft with a compression sleeve and locking nut on the outside of the clutch assembly.

(b) 5/8 inch engine output shaft with a compression sleeve and locking nut on the outside of the clutch assembly.

(c) A tapered engine shaft secured with a spring washer and nut inside the clutch assembly (Villiers 2 stroke engine).

It appears to me that Scott Bonnar 33 had three (3) different engine configurations using the metal-to-metal clutch unit?

Malcolm.