OutdoorKing Repair Forum Forums Finding and Swapping Rare Finds & Donations My Scott Bonnars

I put my 2 Scott Bonnars together recently.The gold base one is a Model 35 and the other is a Model 49.I do have another 2 stroke one,but currently it is in Brisbane.The Model 35 was swapped with VictorVicta the model 49 was found in a hard rubbish collection.
Here are some pictures for you to look at.

Hi Blumbly, thanks for posting the pics, both unusual and great looking machines...I am still trying to get some manuals and info for you on the SB rotaries...They appear to have been known as the "Spin-Cut".

OK thanks Deejay.It does seem to be hard to find any info on them.Which is a bit frustrating.

Hi all just wondering if anybody has found out any information on the black box that the gold mower here pictured has.I'm just getting worried as I really need to do something with it as it is starting to seize up.I just want to get it going,but I have no idea what the box does.I do have a rough idea.If anybody knows anything about it please let me know.I'm now calling it operation save gold scotty.

I am not sure where the black box is you speak of (internet throttled back again and slow loading pics ) but I will be damned if that isnt a copy of design drawings of a victa 18, snap there are some similarities.

Wow, talk about plagiarism....I hadn't noticed how similar they are Joe till I did the coffee table...the handle design, cowling and tank and height adjustment look like a direct rip-off the 18 Special....How did they get away with that...you would have thought that Victa would have had some patents in place wouldn't you?

There is nothing in that part of the design that looks patentable to me Deejay except perhaps the height adjustment gearbox, and they didn't use that on the SB. The appearance cannot be patented, it can only be design-registered. I suspect that either Victa did not register its design, or SB took the view that they had made enough change to not infringe the Victa design. Generally, infringement of a registered design requires that the copy be literally identical to the registered design, not just similar to it or reminiscent of it.

Hi grumpy, thanks for the clarification.

When you get up close to it you can see it is only similar.There are defiant changes so it is only just a basic design that was copied.So I guess that means nobody has any idea about this box I need,or make?

I'm just shocked that nobody's knows about this black box.It's driving me around the bend.Was there anything like them on the reel Scott Bonnar's? Surely one had something like it.I hope fingers crossed.

Some scotty reel mowers had a little tool box on the handle if your reffering to the square shaped bracket at the bottom of the handle?

No no no,on the model 35 (gold one) you will see the wire that is hanging down.That wire went into a black box which connected to the side of the cowl.Now I beleive that's where an on/off switch went,the the spark plug lead came out from that box and went to the spark plug.
You can see the 2 wires here that aren't connected.

Here you can see the hole where the box bolts to the cowl.

Then here you can see the black box on the side of the cowl. Unfortunately it's not the greatest picture to be able to see it good enough to make one.

Oh I see now, as a quick get er running deal you could possibly use the points switching wire to operate a car coil to run it long enough to prevent it seizing up, as for the original black box I have no idea...

Yeah I suppose I could track the coil wire and run that back to the spark plug and maybe I could get it going that way,but I would really like to either find the right box (yeah right don't like my chances there) or maybe to make something that would at least look like it.I guess for now I will have to try that.I don't want it to seize up.That's if it hasn't already.I last looked at it before Christmas.

hopefully the engine will turn up on something, have you found anything specific to the engines manufacture, was it definitely made by Scott Bonnar, and does it have an engine model somewhere?

There is always a chance that engine was on other mowers, which will deepen the pool for finding one.

Ya what you asking me those questions? Man I have no idea.It seems like any information on Scott Bonnar rotary's just ins't out there.It's just not available not like Victa information.

**Update** I spoke to my mate this morning who worked for Scott Bonnar....the engine was made by Scott Bonnar in Thebarton in Adelaide and was a very powerful engine, from memory he recalls that the piston is 2 1/2" in diameter and 155 cc....He and his mates raced that motor on a go-kart and won every race they entered...he still has the trophies....
But, sadly, he can't remember that black box or what is was for....
They were only fitted to SB mowers.

What I can see of that black box looks similar to the electricals box on one of the English 2 strokes from the 1950s. We had a post on it here in the past 6 months I think, with a picture of the black box. I think it contained the points, with a pushrod going into the crankcase to operate them.

I cant recall for sure, but in this case i think it is a little different Grumpy, firstly, I don't think Jeffry has allowance of any kind for a push-rod on this on (could be wrong though) and secondly, I recall hearing something about this box holding some form of secondary coil, the condenser, and a switch.

My mate couldn't recall a black box being fitted...but it is there in the pic...If you look at the pic of Jeffery's mower, there is no provision for a push rod through the cowling or crankcase for a push rod, I think Ty is correct...it may be part of what is described in the brochure (right at the bottom) the Magister magneto's secret!

I am curios as to the function os a secondary coil though, I can see the add now:

"Enough spark to kill a moose... If you have one to spare"

The actual words sound rather like a box containing the coil, the capacitor, and the points.

I'm pretty sure there is a coil under the flywheel on this one too though.

There has to be a generator of some kind, Ty, to supply voltage to the primary of the "real" coil (which I suspect they are calling the "secondary" coil). So, rotating magnet or magnets on flywheel, single-winding coil mounted close to the flywheel (let's call it the generator coil), fairly conventional battery-ignition-type 100 to 1 step-up coil in the black box, along with the capacitor and points. Why would they do it that way? Well, one possibility would be that they had an opportunity to buy the black box and its contents from the English company that made them. If you can trace the British engine that had the similar black box in the archives, it might turn out the whole ignition system is more or less the same. Or it might not. One might still be a copy of the other, though. Meanwhile if it should turn out to be the actual British system on Jeffery's engine, he has more chance of getting parts for it.

Hi guys, as I have posted here earlier....the engine on Blumby's Model 39 was made in house by Scott Bonnar at their factory in Thebarton in South Australia....it is not a British engine.

Thanks guys for trying to help at least I know where trying to work it out.As for the push rod idea.No there's no where for a push rod and there nothing to suggest a push rod.I'm pleased to hear it was made in Australia.Just wish it still had it on it.Would love to find a catcher for it.That would be really good.

The pushrod I was speaking of would be a small plunger, probably 1/4" diameter, running directly into the crankcase from somewhere near the middle of the black box. This would be very like the plastic plunger on a breaker-point Briggs engine - you wouldn't see it unless you inspected the base of the black box fairly carefully. If it doesn't have a breaker in the box, with a plunger, where is the breaker? If you find a set of points under the flywheel, then the black box might only contain the coil. The capacitor needs to be close to the points, so I doubt it would have been in the box if the points were elsewhere.

Hi,
Maybee this is a better place to post the info you want...The gold mower your refering to...is in fact a Scott Bonnar 35,Model 201 series 2.The second series of the first rotary mower made by SB.The 3 wires you have are from the coil,they are joined via 3 x screw fittings that run to the secondry coil."Magister"then on the to spark plug.You will need a secondry coil,to run this mower,as for a spare,Ive only ever seen one intact...And I own it,I can supply you a picture if you like.they did make a few of these in a three series run,but it seems very few survived.Ive been told many times that they would over heat often,making them pretty much a failure.BUT mine runs fine,although I dont mow long grass so Ive not really tested it under load.At a guess going of the few numbers ive obtained they maybee made around 20,000 or so.Anyways I love this model and im currently restoring her now.Only missing a catcher,but i doubt id ever see one.
And the "Magister" is the "black box" some of you are refering to,its a solid state sealed coil unit that amplifies the power to the plug,simple design,but truly,In my opinon totally unecessary since there is enough room on the coil plate to run 2 victa coils.Anyways hope this answers some questions...And YES you wil be able to get an alternative of another mower to run this im very sure.
Please dismiss my previous entry on another of Blumblys posts relating to this matter

Ok have you got some pictures of this set-up?