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Scott Bonnar Centenary Villiers engine and carb ID?

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Scott Bonaaar Wed, 29/03/2023

Hello Gents, My name is Chris, I recently delved into the depths of vintage lawn mowers and picked up an Australian made Scott Bonnar Centenary lawn mower.

I am having some trouble identifying the engine and the carburettor on this little machine and would very much like some assistance before I start a potential restoration of this little gem.

Would very much love if there are any workshop manuals available for this engine and or Carburettor. 

Hope to hear from you.

Cheers Chris

Scott Bonnar CentenaryEngine rearEngine sideEngine frontCarbCarbsideGear Case

Mower side

Flywheel

Forums

Scott Bonaaar Wed, 29/03/2023

More

Scott Bonaaar Sun, 02/04/2023

Anyone??

villiers98 Sun, 02/04/2023

The best place to look is on the Australian forum www.outdoorking.com and go to forums . There seems to be quite alot of info and enthusiasts of the Scot Bonnar machines. There is a nominal charge to join.

From the spitting back check main bearings for wear, use 25 to 1 ( or even 20 to 1) and richen the mixture a little. Sorry I am not familiar with that carburettor.

Good luck

 

Scott Bonaaar Sun, 02/04/2023

Thanks Villiers98, I'll try to richen up the mix I have the ratio at about 20:1 presently. Main bearing wear would cause the backfiring? not sure I follow.

I've tried Outdoor King but the site seems very quiet these days unfortunately. Seeing as Villiers is a British thing I thought I'd have more luck on here.

What is NBSP by the way?

olcadmin Mon, 03/04/2023

NBSP is computer speak for an extra space in a line of text. It was breaking the link to the site mentioned so I have corrected it on the previous post.

olcadmin Mon, 03/04/2023

Chris, by the look of the engine and carb (both made by Villiers) I'd estimate the date to be 1930s. The same combination was fitted onto many other make of mower at this time, including Atco and Qualcast. Villiers made millions of these small engines (it looks like a 147cc but may be a 97cc - difficult to see).

Some of the Atco parts lists and operating manuals on this site might contain some useful information. There is also a good explanation of how to check and change the timing of these engines and also a page about the magneto which you might find useful. It's possible that a tweak in the timing might help it run more smoothly.

olcadmin Mon, 03/04/2023

PS - there are lots of posts on the forum going back many years covering topics such as timing and the carb. A quick search using the box at the top of the page will help find them.