OutdoorKing Repair Forum Forums Restoring, Customising and Modifying Reel-Type Mowers SB Model 45 School Project

Hi all,
For my school project I am reconditioning a Scott Bonnar Model 45. I have found one for sale and just awaiting approval. It isn't running and doesn't look in too good condition but I would much appreciate your advise. As I am only 12 I do not have any experience in the Briggs and Stratton engines. I will upload the images from the seller but I will take some pics when I get it.
Cheers Tom.

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

Reconditioning a Model 45 is a great idea for a school project, and the early solid engine deck 14" Scotty will be ideal for this purpose.

First, it would be good to know the approximate age of the machine, and we can do that establishing the date of manufacture of the Briggs engine.

When you get your hands on the machine, if you look on the engine metal air-cowling in front of the air cleaner, you should see the Model, Type and Code stamped into the metal....We need you to post all the numbers here, and we can give you the date and other information.

We are here to help you....and Tom, once again to OutdoorKing.

Hi Deejay,
Thanks for your help. I am picking up the Scotty tomorrow evening so I will probably be able to take those photos and have them up by tomorrow night so you establish the approximate age of the mower.
Cheers,
Tom.

Hi again Tom,

And thanks for your reply.
I have had a good look over the pics that you have posted and found that (presuming it has its catcher) that it is in good complete original condition, silver Briggs and plenty of life left in the cylinder reel.

Once you decide to which level of reconditioning you wish to achieve for this project, we can supply you with a step-by-step plan of attack that will bring you to a successful conclusion.

Looking forward to seeing your pics,

Hi Deejay,

Thanks for your reply and yes the first pic I posted was it's own catcher. When you say that the cylinder reel has plenty of life in it are you saying I will not need to get it sharpened? So you think all of the parts are original and there are no aftermarket parts?

That would be great if you could guide me with a step by step plan for reconditioning because I don't really know too much about all the parts in an engine and what they do.

I am so glad that I watched your videos and found your forum because I think I would've been pretty lost in finding repair info on the Internet.


Tom

Hi Tom,

What a great project and well done on finding an excellent machine to start off with From what's left of the decal on your engine, it looks like a 2.25hp (61202) Briggs & Stratton engine. When you post the 'model type code' we'll be able to confirm this. At a guess it's around 45 years old.

When Deejay says the reel has 'plenty of life' left, he means that it has plenty of metal left for sharpening. Ideally the reel should be sharpened when the cutting edge wears and no longer gives a clean cut. During sharpening, a small amount of metal is ground away each time and eventually after many years and sharpens, the reel has no width left on the blade to sharpen - and requires replacement.

So in a nutshell, your reel has plenty of metal left, that can be sharpened many times before it would need replacing. From your photos we can tell that it definitely will need sharpening.

There's many threads on here covering SB45 restoration, have a look through and ask lots of questions. I'm really looking forward to seeing your progress. Thanks for posting your info and pics and I wish you the very best of luck with it.

Cheers, Michael

Tom, I notice that you have been focused on the Briggs and Stratton engine in your plans. Unless they have been abused or neglected, those engines are usually quite easy (and inexpensive) to get running well. The remainder of the mower is likely to take considerably more time and money to get into good working condition. You may find it easiest to plan for this project to proceed in stages, probably with assessing and diagnosing the engine's needs as the first stage. With that behind you, you will be better prepared to work on the mower itself.

Because you have an early (one-piece deck) SB45, the machine is potentially a collector's piece, which is worth dealing with carefully one step at a time.

Hi Tom, welcome to the forum. Yes it is a great site to learn and bounce questions off other members. I'm currently restoring a SB45 17" and you will be surprised at the amount (if not all) parts are still available.

If I can offer some advise, the original parts made by SB are of excellent quality and I recommend to have a go at restoring these before you go and buy new ones. You will save a lot of money.

Hi Michael, Grumpy and Corduroy,

Thanks for all your advise and info about this mower. I can't wait to start restoring this, especially with all your help. We are picking it up in about an hour so I should have the photos up around then. I will aiming to save as much money as I can because I don't have too much money.


Tom

I was also wondering if I could obtain the original colors for this SB. I want to restore it to as close the original condition as possible.
Cheers,
Tom.

Hi Tom, you'll need to take a sample of the original paint in to a paint store to have it matched, as there's no record of the original Scott Bonnar formula. The best place to get this is from either the inside of the chain cover or the back of the plate on the handle bars - just take the whole piece with you and ask them to match the paint that's on it. There's a few different greens used over the years, yours is more of an avocado hammertone.

How did you go picking up the machine?

Here is a picture..

I forgot to mention, if you don't have access to a spray gun and compressor, it's probably best to find a paint supplier that can put your colour in to aerosol cans (not everyone does).

Thanks Michael,

I got the machine all good and have tried starting it but cannot. If possible I will upload a video so you can possibly identify the problem. Can't wait for the finished product. I have tried taking the chain case of but one of the screws is bending when I'm trying to unscrew it. Is there anyway I can fix this or force this off without doing any damage to any other parts of the mower. Is this the info you needed Deejay?

Hi Tom, on becoming a Scott Bonnar owner, your machine is a little beauty!

No Tom, the Model, type and Code are stamped into the metal cover that surrounds the Briggs engine, and the recoil starter, now look at the back of cowling near the intake manifold, it may be hard to see, but it will be there somewhere in 3 groups....please post all 3 for us, the numbers may start with 61202...

Just try and remove that recalcitrant chain case screw the best way you can...you can't damage much there that can't be easily fixed.

Grumpy will assist you with your Briggs problems, he will step you through the diagnosis...just do what he asks and post the results. Don't worry mate, it will be fun.
Have you got a suitable tool kit to do the job?

Please take plenty of pics Tom, so we can see what you are doing as you go along.

The numbers Deejay is talking about are located here

They can be a little hard to spot sometimes like the ones in the pic below. Give the area a thorough clean and let us know what you come up with.

Thanks Deejay,

I will have a look tomorrow since it is too dark to look right now. I have some tools but there will be many that I don't have. It will be good if grumpy could identify the reason for the mower not starting. I will definitely be taking many pics as it will increase my marks having progress pics. I only have two terms to complete this and a written report. Will this take too long?


Tom.

Tom, look at the long line of stamped numbers on Michael's pictures of the cooling air cowl. The numbers are in the yellow oval in this copy of the picture:


As you can see, they are just stamped into the rusty steel, so you need to look hard to read them. We need the whole of that long string. The first group is Model, the second group is Type, and the third group is Code. All of it is needed for our current purposes.

Thanks Rolla,

I will have a look tomorrow after school and post a couple of pics. As you said I will need to give it a good clean because of all the dirt that has built up over the years.


Tom.

Thanks Grumpy and I hope you can help me with all my engine problems I may come across. I also noticed that the reel blade is scraping against the sole plate (if that is the bottom blade thing).
Cheers,
Tom.

I was also wondering what fuel this takes? There is fuel in it but is probably old and I don't want to put fuel in with two stroke oil if it does not need it. I was also wondering if this is two stroke or four stroke. I noticed when the handle thing is in the engaged position the cone should be level with the clutch itself. I had to play around with it a bit but got it to come out when the handle is in the engaged position. I haven't opened the clutch yet but I suspect the cork is worn or none left because when engaged it is not gripping therefore not spinning the reel. Hope you guys can help me.

Tom.

Your engine is 4 stroke and takes regular unleaded. There is oil in the sump (well there should be) for lubrication. It's a good idea at this point to check it. There is a round filler plug near where the engine bolts to the deck. The oil should be filled to the top of the thread. I can add some more photos if need be.

The clutch cork should be replaced as part of your restoration and is not expensive. When you get to the dissassembly stage, take some pictures and post them up

I'll just address the engine issues Tom, and leave the mower frame issues to Deejay.

Your engine is a side valve 4 stroke, of 100 cubic centimetres displacement. It requires ordinary unleaded petrol of 91 octane, with no additives, and no oil in it. Do not use 2 stroke mix. Do not use petrol containing ethanol - it slowly damages some of the fuel system parts.

Remember, because it does not have oil in the fuel, the sump must be kept full of engine oil. Check the oil before trying to start the engine.

Real petrol, without ethanol or ether in it, can last a long time - I've used petrol that had been in a jerrycan for more than 5 years, and found no difference between it and new petrol. However petrol containing ethanol gradually absorbs moisture, goes yellow, and then does not operate the engine's carburetor properly. Because we do not know what kind of petrol is in your engine's fuel tank, it should be replaced - but draining the tank properly requires taking some of the engine to pieces, which should not be done unless it is necessary. You could siphon out as much of the old fuel from the tank as possible then fill the tank with new petrol, but it is probably more convenient to just check the colour of the fuel you have. If it has gone yellow, or if it no longer smells like proper petrol, it will have to be drained. Remember, petrol is a hazardous material. It is toxic, irritant, and explosive. Please do not disturb the fuel until we talk about how to handle it safely. Just remove the tank cap, look at the fuel, smell it, put the cap back on, and report back.

Hi Tom,

Don't go adjusting anything just yet, let grumpy help you with the engine first; we will get to the other stuff once we get the engine up and running.

Hi Tom,

I'll also join in here with a big welcome to this wonderful forum and rest assured that any info you require will be easily and quickly forthcoming from us guys.
Being a fellow Adelaidean I did see the machine up for sale originally and thought of purchasing it myself but I have one exactly the same and felt it best that someone else gets a chance at it.
As far as the engine not running there are a number of elements that need to be checked and they are 3 items Fuel, Spark and air. I pretty much suspect that the machine hasn't been used for a number of years and more than likely has a set of stuck closed points and as such you won't be getting any energy to the spark plug. I would first remove the air cleaner box and tip a small amount of fuel directly down the carby (not too much though)and then give it a couple of really sharp pull starts and see if there's any life to be found. If nothing then the next point would be to look at the ignition system which as I eluded to earlier that it will probably be a closed set of points. I have a simple method of checking if you are getting spark and that is probably not the best way and definitely not one for the occupational health and safety people to hear but just put your finger on top of the s[park plug and get a second operator to slowly pull the starter rope through the cycle and if there is spark you'll know about it instantly as soon as the rope is pulled (SLOWLY)as you feel a bit of a electric shock on the finger. Like I said it's probably not the best option if you've got a heart condition. The other way is to take the spark plug lead off the spark plug and use a rag around the lead to hold the lead with you hand. Now hold the lead so that the metal end is about 3 mm away from any metal part of the top of the engine and using a second operator get them to pull the started rope with a bit more motion and see if you can spot any spark jumping from the metal end to the engine, if no spark at this point you will have to investigate further into the ignition system.

If you need a hand I'm more than happy to help you out personally, that's providing you're not at Christies Beach or somewhere down that way.

Let me know if there's something I can do for you.

Cheers,
BB

All good I got it running!!! There is a problem with the pull start because sometimes it won't engage an spin the shaft. The stop and run switch does not make a difference when turning on or off, the only way to stop the engine is to use te choke which sometimes takes a while. It was running pretty fine as I said earlier the cork will definitely need replacing as sometimes the come does not grip therefore not spinning the reel. I am in the Walkerville area, where abouts are you?

Cheers,
Tom.

It's great to have a fellow adelaidean here to help me!!

This is one of the screws on the chain case. Any ideas of how to unscrew it since it only bends when I try to unscrew it.

Sorry for the late reply Grumpy but yes the fuel did smell like normal petrol so I think it was all good!
Cheers,
Tom.

That engine does not have a kill switch incorporated in the speed control, Tom, you stop it with the piece of metal on the top of the engine, which contacts the top of the spark plug when you push it in that direction. This shorts out the ignition, without doing any harm.

This thread has now wandered off track from my point of view, and I will not be taking any further part in it. I hope your project works out well.