OutdoorKing Repair Forum Forums Collectors Corner Cylinder Probably one of the Last 14 inch SB 45's made.

Hi All,

I have accidentally fallen across what is one of the very last 14 inch Model 45's made in the Scott Bonnar range.

There has always been a bone of contention as to when the 14 inch twin railer ceased production. There was a line of thought that the 14 inch unit finished up at the end of the Kirby equipped machines but I have proof that the twin railer lived on into the orange painted Briggs days.

Have a look at the following photos and you'll see that this one is of the Apple Green variant, and has a 2.5 Hp Briggs & Stratton engine that's dated the 3rd of October 1975, which means that with the date of motor manufacture and assembly of chassis normally being around 3 months later that this machine would've been assembled at the end of December 1975. One must take the Christmas close down period into consideration with that being at least 3 weeks from December 24 and thus that would put the assembly date around the end of January.

Note that the handle bar still utilises the earlier throttle control as used on Kirby powered machines and the first Silver Briggs Powered 14 inch solid deck machines and there are no screw holes in the bar for the newer designed black plastic unit that was fitted to just about all the a Jonathon Apple coloured machines, which is proof of this control being fitted as original equipment. Also it has a new model number meaning the Briggs is original and not substituted for an old Kirby. We have already established that the change from the Kirby power plant to the Briggs units across the range happened while the 45's were painted in the darker Alpine Green and were fitted with the black chain case and handle bar shield. After that colour scheme SB changed to the Jonathon Apple Green which ran right up to the companies acquisition by Rover in 1980.

The handle bar grips are also of the later version. All in all a very important find for the history of the 14 inch machine and providence of it's demise being somewhere around 1976 and no earlier as it's been commonly believed to be.









Lastly the sticker on the Briggs engine proves that this engine was fitted to a 14 inch Scott Bonnar. (the "1" has been accidentally scratched away due to the line in the block casting and thus it reads like it's a 4 inch machine which we all know never was made)

The machine is an original one owner machine and was discovered by myself as a job for a reel grind at an Adelaide mower shop.

I don't think much more proof is needed to support what I've suggested.

Cheers,
BB

Hello Mod BB & Simrice

We now have a new model for our records: the 450511.
A 1976 machine (I guess) with a late 1975 engine.

It is fitting that the little 14, started life with a Briggs,
quickly went to Kirby, and returned to Briggs.

I have just realised something significant in why the 14"
was retired from the range sometime between 1976 and 1978.

The answer must lie with events happening at that time, the most
important being the takeover of Flymo-SB by the Challenge Corporation
in 1973.

An easy argument would be that SB was rationalizing its range due
to the significant decline of the reel mower. But...
Here's the 1978 line-up:



I think I understand how NZ Challenge's ownership did not rationalize the
reel mower line-up at all. It changed its composition and increased it!

This is seen in the photo's composition.
The 14" was replaced by the cheaply designed 16" SB Morrison.
It is significant that the 16" is placed in the 45 17" & 20" lineup.
The new reel mower range would be: 16", 17" (X3), 20" & 24".

And that includes the two new Diplomats (introduced in 1976).
Effectively, this meant SB offered, not one, but three 17" reel mowers!



In other words, the beautiful little 14" was sacrificed to
corporate demands - to accommodate the new Diplomats and get Challenge
Morrisons in the AUS line-up required a sacrifice! The 16" Morrison and
the Diplomats were clearly cheaper to manufacture than the 14" SB45.

The SB45 14" was dead. Long live the 14" SB45.
Thanks BB for finding this significant last SB45 14" model.

---------------------
Jack

Hi Jack,

Honestly I instantly fell in love with that one and am still considering offering a sum of money to purchase it outright and turn it into a groomer alongside my first 1968 Solid deck machine that has been my daily driver for 35 years now. I'm starting to feel that the 14 will fit in better with the size of my lawn and the profiles of the ground that the lawn is based on. A 20 inch is out of the question and I have so many 17's on hand it's not funny. Maybe I should do up a 17 machine and offer it as a straight swap.

I am just so happy to finally be able to seriously piece together the model 45's illustrious history.

Cheers,
BB

Hi BB

I must say, your post forced me to revise the view I had of
vintage mower history in Australia (at this time).

My own experience tells me that reel mowers were not in 'niche'
territory in the 1970s. It was a valid sector, competing with
rotary mowers at this time.

The issue for me, now, is to what degree lawnmower manufacturers
themselves - rather than the market - contributed to the decline
of reel mowers in this country.

Within a few short years - the 1980s - reel mowers would be all-
but obliterated from the landscape.

Your post - and recognition of the last 14 SB45 has certainly
provoked thought...

Cheers
-------------------
Jack

Hi bb,

I have I 1968 solid deck Scott bonnar 14" with the Briggs and Stratton engine the same as yours. I would love some advice on that engine as mine runs for about 15 mins then cuts out. I am also wondering how hard it is to rebuild the engine, I can't afford for my local mower shop to do it. Thanks in advance


Joey

1968 14 inch Scott Bonnar

Hi Joeyvek,

It sounds very much like a heat induced issue and as such is more than likely an electrical problem with the HT lead or even the coil. Heat induced issues are always harder to diagnose than problems that are there constantly and can be found quickly.

The rebuilding of these engines is rather simple if you have the relevant tools to do the job, eg. Valve grinding machine, seat cutting tools, boring bar if required, and I hear you saying this is easy ?

Most of these engines only require a light hone of the bore, a new set of rings and a valve grind and then they are away for another lifetime. I really need to do the rings in mine as it's blowing blue smoke in short bursts.

Sadly sometimes it's easier to just do a power plant swap as there are plenty of 2 ~ 2.5 Briggs & Stratton engines out there from other mowers to be had for around $20 ~ $40.

Cheers,
BB

As BB says, it may be the coil. But the first thing I would be checking is the valve tappet clearances - these can also cause this sort of problem.

Excessive debris in the cooling fins can cause this issue as well

Thanks for the advice guys. Bb where do you find these engines so cheap. I was thinking of getting a new engine from my local shop for about$200 but if I don't have to do that I won't. I mean I only paid $80 for the mower and I love it. Where would I find a cool for it

Hi guys I have worked out the reason my sb45 is stopping. Found out that it is the coil.



Thank you so much for the advice


Joeyvek

1968 Scott bonnar 45