OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Walk Behind Lawn Mower Frames Question On Scott Bonnar Cylinder Mowers Model 33 [Help identifying model and year]

Hi All,
New to this forum and new to Scott Bonnar Reel mowers.
Can anyone help identify this mower - I've looked and can't see anything that seems to match this in appearance.
Info I have on this is the engine; Kirby Tecumseh HK25 Spec No G1005 Serial Number 7324 4390.

It was put away in the shed by previous owner when it broke down - 23 years ago.
No Spark - so replaced all the ignition parts (second hand from some online mob in WA), new spark plug and air filter, and cleaned the mud wasp nests out of the carby.
Changed the oil and ........ I'd be exaggerating if I said it started first pull of the cord, but it didn't take 10.
And now starts really easy, runs OKish (hunts a bit) and cuts grass pretty well.

Any ideas on Model and Vintage appreciated.

I think (hope) I've attached a photo of the mower.

Cheers

Scoee

Personally I'll wait to see what Deejay says. It looks to me like an early (single deck) Scott Bonnar 45. If you post a few more pictures from different angles, Deejay will be able to confirm that and point out any non-original features it may have. If you include close-ups of the cutting reel, bedknife and chains/sprockets (have to take off the chaincase on the left side), he can comment on its general condition as well.

Because it is such an early example, it has a Kirby-Lauson engine rather than the Briggs and Stratton engines that came slightly later. This makes it difficult to set a date (the Briggs engines have year, month and day coded on them, but the Lausons are way more subtle). It would appear to be between 1968 and 1971, but Deejay may improve on that rather wide range.

Thanks Grumpy,

Here's a couple more of different angels.
I don't have a photo with the chain guard off - but it has both chains and a belt under the cover.
I've been looking a bit further this morning and I think it might be a Model 33

You are right, Scoee. I couldn't see the belt in the original picture, but I should have paid more attention to the round cover plate on the right hand side plate. (We'll say nothing about me not noticing that the drum clutch has a steel rod linkage, where the SB45 had a Bowden cable.)

There should be a Scott Bonnar ID plate riveted on it somewhere, with a serial number. The first two digits of the serial number are the model number.

If you haven't seen this thread, you might be interested. There are also several others on the Model 33:
https://www.outdoorking-forum.com.au/forum/u...amp;Main=7650&Number=41184#Post41184

Hi Scoee, and a warm welcome to the forum.
It's nice to have another Scott Bonnar owner on board, as we all like to learn new things and tinker here.

Your machine is a 16" Scott Bonnar Model 33 with a Kirby-Tecumseh HK25 2.5HP 4Stroke engine.
The model 33 was first introduced in 1960 and was still included in the SB Selected Equipment Range 1974-1975, though through some research, I have found that it is thought to have been discontinued in 1966.
Here is a pic of the 1974-75 range:


Once again Scoee, to OutdoorKing.

Thanks DeeJay and Grumpy,

Wow, I thought it must have been a few years old ... but now I know it's at least 47 and as much as 54 I'll treat it with a bit more reverence.
And I haven't found the Scott Bonnar ID plate yet - only the Engine Plate

Any advice on items I should look at servicing / oiling / replacing, given that it is of this age and has been in storage for 23 years.

I've changed the engine oil with 30 grade, the chains look plenty lubed, and I've put a drop of oil into the ?Thrust Bearing (perhaps) - along side the clutch.

Cheers

Scoee

Hi again Scoee, I may have some advice for you but without the pics I am flying blind....As grumpy has said in his previous post..." if you include close-ups of the cutting reel, bedknife and chains/sprockets (have to take off the chaincase on the left side), he can comment on its general condition as well".

Once they are posted, I will give you a detailed reply on my observations.

Hey Thanks for the input.
Here's a few photos - tell me if there is anything else I should include.

Cheers

Scoee

Hi to Scoee and ODK members,
Here are my observations:
The cylinder reel has plenty of life left in it, as does the bottom blade...However, both need to be professionally sharpened....Have a read of my post HERE

It is a bit hard to see the profile of the cutter sprocket because of the angle the pic was taken, but given its age and the fact that parts for the Model 33 are very thin on the ground, it should perform reasonably well into the future.
The inner cutter pulley is in serviceable condition.
If the cutter clutch and drive clutches are working correctly, it would seem that you have a nice machine, and would make a nice restoration, if you choose to do so.

Those chains are dirty with grit. They need to be removed and cleaned, then lubricated. While they are off you can easily wear-check them by holding them horizontally, on edge, and measuring the sag in the center.

Thanks again Grumpy and Deejay,

I'll hunt around for someone on the Gold Coast who can sharpen this for me - any suggestions?

I'll also look to clean and lube the chains and replace the drive belt while I'm at it - is the drive belt a fairly standard Vee Belt (fan belt) or something special?

Looking at some of the examples on this forum I'm a bit inspired to clean this up and smarten up the paint work.
I don't expect I could come close to some of the restorations though.

Cheers

Scoee

Hi Scoee,
Re: Sharpening, if you talk to your nearest local Bowling Club or Golf Club greenskeeper, and ask where they get their reels sharpened, they are usually a friendly bunch and will help you.
You remove the reel and the soleplate (complete with the bedknife still attached) and take both to the engineer/machinist who will sharpen them for you.
If you need help with the removal, we can step you through that.

V belts are primarily described by two dimensions: the width of the belt at the top, and the length around its perimeter (which unfortunately can be measured in several different ways: outside, inside, and effective lengths). Common or garden V belts are A, B, C, D or E section. A section is 1/2" wide, B section is 21/32" wide, C section is 7/8" wide, D section is 1 1/4" wide, and E section is 1 1/2" wide. Depth increases approximately in proportion to width.

There are less common V belts of different widths from the above - usually they are narrower, and are made as automotive fan belts. There are also various qualities available. Do not use a washing machine belt as a fan belt (and don't ask how I learned that lesson).

Here is a listing of all the standard off-the-shelf V belts available from industrial suppliers:
http://www.vbeltsupply.com/conventionalvbelts.html

Don't despair if it turns out to be a fan belt type (often 3/8" wide, and thus not a common industrial type). Just about anything is available from somewhere.

Hi Scoee, if you look carefully around the circumference of the belt, you may find some reference numbers that may help you identify the belt size and/or manufacturer.

Thanks guys,

I'll let you know how I get on.

I can't believe how helpful you have been.

Cheers

Scoee

Hi everyone,

Can you give me an idea if this is a 33 or a 45?

https://photos.app.goo.gl/ZdrACi33JS8jgWBd8

https://photos.app.goo.gl/jVhNcJvE2hxvNqQy5

This is a Model 45 which should be depicted on the ID Plate that's attached to the rear engine mounting rail on the drive train side.

If the handlebars are original then it's quite possibly a Craftsman version of the Model 45 which was a store branded release. This one has had an engine change to a current model Briggs unit.

Cheers,
BB.

Hello bigwids
This is a version of the Model 45.

In the Blue Bar (above) type: -
- Model 45 Craftsman, and then;
- Model 45 Lawn King.

My best guess is that it presents as a Craftsman.
[Assuming the catcher and colour are original]

The Maker's ID plate should give the game away.
[A close-up of the Model Number would help.]

Hope this helps.
-------------------------------
Jack

Hi guys,

Cheers for all the info, so I’m going to buy my first cylinder mower next Saturday from this guy. Just told me he has two to get rid of one was his dad’s and the other his cricket club so possibly be buying two lol