OutdoorKing Repair Forum Forums Restoring, Customising and Modifying Reel-Type Mowers SB 45 garage find

Hi forum,
I posted a few months ago with a 590 diplomat. Came to my senses and put it back on ebay, just wasnt worth restoring.
Last week I won an auction on the sb45. $70 pick up. I was pretty weary about the condition but from the one pic that was on the auction it looked worthwhile. As long as the motor Wasnt seized. Turns out it was just dirty and in need of some rp7 and a rag. Can somenody tell me thr year it was built please. Mower no. 04338. Model no. 450589
I will post some pics as soon as i finish cleaming her up.

Mate some details on the engine and a couple of pics could go a long way on getting a build year, joe.

The serial number does not translate into a build year for the SB45. Two things will help, however: pictures of the mower, so our SB guru can tell which running changes it does and doesn't have; and if it has a Briggs and Stratton engine, the long series of numbers stamped onto the side of the cooling air cowl. The numbers on the engine will give us the day, month and year it was built, and more likely than not the mower was built just a few months later, if it is the original engine.

Hi scoffey86, and welcome back to the forum.
As you would know, it is impossible to date a Scotty exactly but, with the complete string of numbers on the air-cowling on the Briggs, we could give you the year of manufacture of the engine.

This narrows down the year the mower chassis may have been built as Joe has said.
If the machine has the Kirby-Tecumseh engine we are not so lucky....
Photos of the machine, particularly a front view of the cylinder reel and one with the chain case cover removed, so as we can see the sprockets where they are not covered by the chains...we can then give you advice on their condition.

Hey Grumpy... great minds think alike (or fools never differ, as my wife tells me!!)

I think your wife's version doesn't work, Deejay. An old saying that I actually agree with: "Only a fool argues with a fool."

There are some photos of the scotty.
I sorted out the age: 10th June 1977.

Now im getting into the problems though, cant get it started.
Changed spark plug, oil and fuel. The whole unit looked in really good nic for something that is 30-odd years old. So I'm convinced that it shouuld be something small that I just don't no how to do...

Is it just flick the switch on the handlebars to start and pull the cord? Am I missing something?? Motors turns no problems but no spark. A mate at work said their may be a kill switch?

I did notice however that when i pull the cord the reel spins. With the lever on the horizontal green bar engaged or disengaged.
Any thoughts?
cheers

thats in real good nick scoffey. Reckon the ding in the reel can be fixed & the blades have heaps of meat left. Sounds like the clutch may need some adjustment.
Deejay or Grumpy will likely assist in getting it started.

cheers Ross

Thanks Ross, there is only the one ding in the reel so hopefully easily fixed. Im pretty stumped about this clutch though.
I've never done anything with mowers before so I'm pretty clueless at the moment.

Hi scoffey86, and thanks for the pics...the machine looks in brilliant original condition for its age and obviously hasn't done a lot of work, except, maybe, for the cylinder reel.

My observations from the pics:

(1) The machine is a genuine Scott Bonnar Model 45; 17" cutting width, with original paint scheme, vertical chain-case screws, black plastic grass deflector knobs, plastic front roller end caps...3HP orange Briggs and Stratton....all pointing to a build year of approximately 1977 for the chassis. (Not that far apart from my own machine, which is almost identical, originally)

(2) The sprockets and chains are in form what appears immaculate condition for their age. They look a fraction tight in the pics, and maybe require some adjustment....easy-peasy to do; and can do with some good quality grease to keep them in great condition for the future.

(3) Looking from the front, the right-hand rubber grass catcher support block is missing....you will need to replace this...as it is important that the catcher sit level on the machine to do its job properly.

(4) The cylinder reel (as Rossf has said, has plenty of meat left) is correct, but the damage that has been caused...(bottom to middle blade, first pic, Right-hand, fourth quadrant; will need to be straightened by the engineer that sharpens (spin-grinds) the reel, which it desperately needs, to do its job properly.

(5) From the condition of the cylinder reel, I will guess that the bottom (knife-blade) will need attention from the engineer as well...for instructions how to remove it; (as both the reel and the sole-plate (complete with the bottom blade) need to go to the engineer at the same time...Click.... HERE

(6) For what happens there at the engineering workshop and some tips...Click... HERE

(7) From what you have said, the cutter clutch needs adjustment; (or may have worn out its cork lining) but I doubt that, I think it will just need adjustment...which I will guide you through at a later date.

(8) Grumpy, our excellent resident Briggs and Stratton guru, will guide and help you through the engine issues and hopefully will have it purring like a kitten.

(9) The front roller may also be worn and need attention....there are some good threads which you may care to read in the Scott Bonnar forum on this issue.

You have made a great purchase here, and with our guidance and some patience....this machine will give you hours of mowing pleasure and a fantastic lawn for you to be proud of.

Thanks for your thoughts deejay. I watched your youtube vids. There great, thanks.
I'm going to remove the reel and bottomblade this weeknand get them down the mower shop for a sharpen. The bloke said bout $50-60 for the reel. So around $100 for both I reckon.

While they are away I will loosen those chains slightlynand grease them up a bit.

My plan for the unit is to just restore it over winter and when spring comes around hopefully I have finshed it and its like new!

Hopefully we'l get some good advice from grumpy to get her running. From its exterior I cant imagine the motor being in to bad a condition.

Hi Scoffey, let's talk about how to get that Briggs running.

First, checking the spark. Remove the spark plug, reconnect the plug lead to it, clamp it against an unpainted metal part of the engine (usually the cylinder head), set the controls in the start position, and pull the starter, watching the gap between the electrodes for a regular series of blue or white sparks. You may hear them too, as a series of clicks. If there is no spark, the first suspicion falls on the spark plug. Put a short piece of metal rod of the same diameter as the spark plug tip into the end connector on the plug lead, hold it by the insulated connector so it is about a millimetre away from the cylinder head, and pull the starter. If there is no spark directly from the plug lead to the engine, something is wrong. The most likely problem is that the kill wire is grounded.

The kill wire is there to switch off the engine. It grounds the moving breaker point (your engine is pre-1982, and hence has breaker point ignition). The grounding happens near the throttle: when the speed control on the handlebar is pulled all the way toward slow, at the end of its movement, the lever connected to the far end of the Bowden cable grounds a wire, which will be black unless it has been painted over with that orange. When the speed control is pushed to the start position, it should move that lever at the carburetor end all the way in the other direction, and it should pull the choke out as well (your engine has Choke-a-matic choke system).

I suggest you run through that process and see if your ignition is working, and if not, whether the kill wire is being grounded at the carburetor when you are trying to start it. Once you post the results of that, we should know enough to move forward with the test program.

hi grumpy, tried what you said about the spark plug. No spark what so ever...
So I'm assuming that this kill switch could be the issue.
So I had a look at the choke area that you mentioned. All seems to function well moving as I move the choke lever.
I have found a wire that is just floating in the breeze, this cant be correct. Any thoughts? In the pic it is inbetween the fuel tank and the pull cord.


The first photo is with choke on, then the second with choke off.

That looks like the kill wire terminal that should be attached to the governor mechanism. However it seems to be floating around not touching anything, so by itself, that would not kill the spark, it would prevent you from stopping the engine.

It appears you will need to remove the cooling air cowl and trace that wire, to see whether it has become grounded somewhere along its length.

hi grumpy,
Traced that kill wire back and not grounded as far as I can see.
So I'm thinking that I need to take it down to the mower shop and get him to take a look at it for me.

I still find it strange that when I pull the cord the reel spins. I'm thinking there may also be and issue around the lever that engages the reel.

If you don't want the reel to spin when you start the engine, you need to disengage the clutch in the engine shaft, between the engine and the chain case. If the clutch drives when you have the lever in the disengaged position, the clutch is misbehaving, but this is not difficult to fix. You have to see whether the two halves of the clutch separate, compressing the spring, or not. If the spring does not become compressed, there is a problem in the clutch external mechanism.

There is nothing wrong with taking it to the mower shop, but there is more satisfaction in at least finding out what is wrong, before you do it.

Hi scoffey86, this seems to be just an adjustment issue; as you move the cutter clutch lever to the disengage position, the actuating fork presses on the black plastic thrust pad, which in turn pushes the clutch cone (the inner part of the assembly) inward to disengage....it doesn't move inward much, to do its job....

To adjust this, you need to undo the lock-nut and wind the screw (attached to the actuating fork) inward and check to see if the clutch cone is moving inward and then rock the clutch backwards and forwards to confirm it is disengaged.
The trick is now to engage the clutch and make sure it is fully engaged....if it is, lock up the lock-nut ans re-test to see all is well.
Please let us know how you get on.

thanks for the advice guys, ended up taking it down the mower shop...
$300 later the motor is running pretty well and the clutch issue is sorted.
The mechanic put a horible kill switch on top of the motor itself which I'm not real happy about. I will post some photos soon of it.

Anyway I have started to put it apart to respray and clean it. Really suprised for something of that age how easily you can undo the nuts and bolts! must have been built well back then.