OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Walk Behind Lawn Mower Frames Question On Scott Bonnar Cylinder Mowers Scott Bonnar ID please

Hi there folks, top site/forum thanks.
Found this ripper old mower at a garage sale and would dearly love to know what it is, Model, age.
Any info much appreciated.
It has Scott Bonnar Ltd Adelaide on the catcher, Villiers motor.

Hi Paul, and a warm welcome to the forum.
It's great to have another Scott Bonnar owner on board.

Your mower is a Scott Bonnar 'Centenary' model, first introduced in 1936,
and came in 16"and 18" cutting widths. Not much is known about this mower but the original Centenary was a 16" and had a cooling shroud on the right hand side over the cooling fins of the Villiers, and some sort of vertical plate, hinged in front of the motor, maybe to cover the opening of the grass-box whilst mowing, to stop the clippings flying everywhere.

Here's an advert for the Centenary;

Paul, could you please take some more pics from all angles and post them here, it would be great for the forum archives.
Also can you please post what's written on the brass mower ID plate, fastened to the machine, just above the engagement end of the crank handle.
Once again Paul,

I'd certainly like to see more pictures. At the moment I'm guessing that the crank handle fits into the end of that shaft on the same side where it is stored, below the bottom of the flywheel, and drives the opposite end of the crankshaft. I don't see a ballrace at the end of the shaft, so there may be a ratchet involved. This seems a bit exotic, but after all the machine is British. Now that I've guessed, naturally I want to know if I'm right.

Hi grumpy, it fits into the dog that is on the end (red shaft) of the 'counter -shaft' that would (I'd guess ) have a sprocket and chain drive to the engine crankshaft. They work well. There is a bearing on the inside of the chassis side rail, fastened as you can see, by the 2 bolts, either side of the dog.

Great stuff and many thanks, much earlier model than I anticipated.
Just joined that Photobucket mob and will most certainly post more photos.
But its about 10am here, (got up at 6), and about 2 coffees short of growing half a brain, onto it

Just a sidenote, I'm an Indian Motorcycle nut however this spins off in all directions and now, the Villiers motor.

Thanks Deejay, I missed the 2 bolts and thought it just had a location collar. So you tend to have an exciting time snatching the crankhandle out of the socket after start-up? I can't see an over-running arrangement that allows the handle to disengage from the socket. A spring-loaded pin in the socket would do it, if it has one.

I can remember having to do a precision job of making a crankhandle for a Lister once: it had a spring-loaded pin that engaged a keyway in the end of the camshaft, and pushed out on overrun, but if the crank was slack on the end of the camshaft where it engaged, they were reputed to grab and spin with the camshaft. Since it was a big two-handed handle with a long overhang, having it spin would be more exciting than I preferred.

Hope these shots give a better insight into what the machine is, thanks

Hi again Paul, Thanks for posting the pics.
Yes mate, yours is an 18" later model "Centenary" from the late 30's and a really great score, mate!!
Are you going to restore it?

It would be interesting to know what they mean by "differential in drums" - it would be possible to really have a center differential, but it would require a drive shaft through one drum to the differential, and probably a concentric bearing to support the drum at the center of the mower. On the face of it, it seems like a natty idea, if you could keep the oil in and the dirt out. However everyone ended up with a pair of sprag clutches instead. Of course they may have been using advertising language when they referred to a differential, and they really meant the usual pair of sprag clutches. A diff is way better when you want to make turns, but not so great if one of the half-drums hits some mud.

Tough call Deejay, mate think I should leave this one to the pro's to restore, but was attracted by the Villers motor and just bought it as a curiousity.
Who knows may sell it down the track, may have to so I can keep the ball rolling and buy more good tucker from the past.

Looks almost the same as my Centenary model - perhaps a bit later with lighter handles.

Stationary

Nice one mate, hey would be pretty hesitant to do a restoration on one of these babies worried I might stuff it up?
So yeah would consider putting it up for sale but wouldn't know where to start.

Before recieving this much appreciated info dug this pic up doing google images search, which gave me idea of what size the Villiers motor is, assuming this is nearly the same as the Centenary?