OutdoorKing Repair Forum Forums The History Forum Model Histories SCOTT BONNAR Models MODEL 43 - 20" POWER REEL MOWER

Hello ODK History Lovers

The Scott Bonnar Model 43 was a 20-inch power reel lawnmower made from about 1960,
with production probably ending in 1968 (when the Model 45 was released).

The Model 43 is not well-regarded, or even generally recognised by Scott Bonnar
collectors. The 43s are rare today; because sales were poor back then. I think
I know why ...



This is a lovable mower, but one must understand the historical context in which it
was designed to appreciate it even more. It was technically flawed, but of a handsome,
rugged design.

It would appear - at least to me - that Scott Bonnar understood their traditional market
very well, but initially struggled to adapt designs to a new post-WWII market, when
residential (domestic) power lawnmowers became available - and affordable - to a mass
audience of purchasers. This is the Model 43 story.

TO BE CONTINUED ...

PART TWO - Specification
The Model 43 is a strange mix of previous Scott Bonnar reel mower designs.

The engine was a 2-stroke of Scott Bonnar's own make - the 155cc Model 202 engine.
That's odd - given that the smaller 14" and 16" models offered 4-strokes!


Source: Grant Simpson Collection.
Note: the Villiers Magistar Ignition Unit ... meaning this machine is c1963 or later.

The transmission is as odd as it gets. The primary chain drove an Idler Sprocket.
From here, there was distribution of power via a gear-sprocket arrangement.
The reel was driven via chain; the landroll via a gear train ... in a Model 17
(Supercut) fashion. This would have been an expensive design folly for a
residential lawnmower.


SOURCE: eBay, 2017

The technical defect must remain with the clutching system. There was one primary clutch
controlling the reel and landroll. This is extraordinary! Both the smaller sizes (in the
domestic range) had a primary and secondary clutch by this time. The 43's single plate
clutch was not a step to the left, nor a jump to the right. It was a step backwards for
such a wide cut machine.

One large plate clutch controlled both the reel and landroll. This would have made
maneuvering quite difficult. This was a lawnmower for the open spaces - the large and
'easy' residential lawns that are not so common.

The rollers were aluminium. Scott Bonnar had used this alloy on some electric models,
and on bowling and golf green machines. The post-WWII idea was that good lawnmower
design should not make the reel lawnmower act in dual roles - lawnmower and turf roller.
The primary purpose of the roller was to produce lawn stripes (an aesthetic reason),
rather than unnecessarily compact the turf.


SOURCE: eBay, 2017

TO BE CONTINUED ...

PART THREE - Domestic Range & Usage
In the post-WWII era, Scott Bonnar expanded - with a keen desire to engage
both the new domestic market and the traditional professional one. It wasn't
that Scott Bonnar hadn't made machines for residential areas (they most
certainly had done so), but that a much larger market of more prosperous
consumers could buy - for the first time - a power lawn mower.

It could be argued that the Scott Bonnar Company didn't think this through
for their domestic models. They had learnt (probably from Atco) that a good
lawnmower design had to have scalability, a design principle whereby the same
basic design could be made in various cutting widths. We see this in their
first professional lawnmower design - the Model 17 Supercuts that were
scaled in various sizes from 14" up to 24" in that model's history.

However, that principle was not followed on the domestic model side.
Their first effort - the 14" Model 19 of c1953 - was built for a specific
market on a budget. It was a flawed design that could not be scaled-up.

Neither could the replacement - the 14" Model 40 of about 1960. However,
by 1960, Scott Bonnar did have a domestic range of mowers. Without scalability,
the ridiculous thing was that the range - 14", 16" and 20" machines - was
comprised of three separate designs: Models 33, 40 and 43.




In the above brochure (c1960) we seen Scott Bonnar's cohesive attempt at
unifying the domestic range - there was a common aqua green colour. Apart from
that there is little commonality between the three diverse models.

The Model 43 portrayed here is most unusual, and none have been found in modern
times. It has an engine-mounted fuel tank and a Model 17 style handlebar.

USAGE - Large Residential Lawns
There should be no doubt that the Model 43 was part of the domestic
Scott Bonnar range in the 1960s. It had a higher specification in that
it had an 8-blade reel and it certainly had a heavy duty specification.

It would not have been a golf green mower on professional courses - the
Model 17 was the machine for that. Nor could the 43 be fitted with transport
wheels. Its width of cut was too narrow for bowling greens.

Its main purpose was for the cutting of larger residential lawns.
It certainly could have been used commercially - for club house surrounds,
practice putting greens, croquet lawns, contract lawnmowing, and the like.

TO BE CONTINUED ...

PART FOUR - Manual

Acknowledgement and thanks to Scott Bonnar Historian Grant Simpson
for the scanning and use of this manual.

SOURCE: Grant Simpson





SOURCE: eBay 2017

PART FIVE - Conclusion
The only significant change to the Domestic Range occurred with a cosmetic
makeover - Hammertone paint was used on the Models, 33, 40, and 43.

The Model 43 is the rarest - by far - of the three models.
It was flawed in having a single clutch to engage reel and roller.
Having said that, it was of a rugged design, with a complex transmission and
the very interesting SB 202 2-stroke engine.

The reality is, though, the range had no real commonality in design at a
time when reel mowers were being challenged by the rotary revolution. I'm
sure Scott Bonnar saw and understood this; and that a single new scalable
design was needed ...

It would take Scott Bonnar another few years to unify the domestic range
into one scalable model - the great Model 45s of c1968.

The rest is history.
------------------------------------
Jack

Scott Bonnar Models:-
https://www.outdoorking-forum.com.au/forum/ubbthreads.php/forums/155/1/SCOTT_BONNAR_Models.html


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