OutdoorKing Repair Forum Forums Restoring, Customising and Modifying Reel-Type Mowers SB 45 Full Restore - Rookie

Hi all,

I've recently joined ODK and WOW - I have learnt more about lawnmowers in the last 2 days then I thought was possible! I've just bought my first ever cylinder mower on the weekend. It's a 17" Scott Bonnar 45 and from what I have read on these forums I would place its approximate build date somewhere in the late 70's.

I am actually waiting to pick the mower up until this weekend so I will post plenty of photos and information on the model number stamps etc. as I have seen that often the pictures are requested to help the rest of the community identify the exact model. I'm not sure if this will count for much, but mine looks to be exactly the same as 'peettees' in this thread SB 45 Rebuild First Timer. It also appears to be in similar condition to peettee's (prior to his rebuild of course!)

I am interested in doing a bit of a rebuild myself but unfortunately I have zero experience in disassembling and reassembling an old mower. To be honest, I have been trawling the restoration section of the forums and a few of the guys on here have mentioned it isn't as hard as it looks - this has probably encouraged me more than anything to take on the challenge!

The mower has the original 'international orange' coloured 3.5HP B&S engine on it. Ideally, I don't want to shell out to replace the engine just yet as it works great currently, but I would consider a new one a little down the track if necessary. For now, I was hoping to spray the engine with the 'chevy orange' high heat spray paint from Super Cheap Auto as I have seen in other threads. Ideally I would also like to fully dismantle the entire mower, have everything stripped back and sandblasted and repainted in the hammertone dark green colour.

There is a brand new bedknife on the mower but the cylinder was at the end of it's life. The gentleman I bought it off has forgotten more about Scott Bonnar's then most people have ever known (well at least that was what I thought until I discovered these forums!). He estimated I might get a few more years out of the existing cylinder, but since then he has offered to fabricate one for me. I understand that might send off a few alarm bells with people on here, but he seems to know what he's doing and has handmade plenty before so I'm thinking I'll give him the benefit of the doubt (plus it seems like a pretty good deal for $150).

My apologies for the long winded post. Can anyone comment if the above restoration is feasible for someone with little-to-no experience to undertake? I'm up for the challenge, but just don't want it to cost an arm and a leg!

Many thanks,

Kenny.

Hi Kenny, and a warm welcome to the forum.
Its always nice to welcome another Scott Bonnar owner on board, as we all like to learn new things and tinker here.

We do believe that if you closely follow the steps and advice we give you as you move though the restoration, a person can reach a successful conclusion with little-to-no experience, as has been done before on this forum.
Re: the cylinder reel, we would like to see a pic of it before you commit to the previous owner to fabricate a new one....there may be alternatives for you to consider.

We will require pics of your machine from different angles including the cylinder reel, cutter clutch, and the inside of chain-case and of the sprockets where not covered by the chain. This will allow us to assess the condition of your particular machine.

Once again, Kenny, to OutdoorKing.

Hi Deejay,

Thanks for the warm welcome. I am actually picking the mower up this weekend so will get plenty of photos then and upload them this weekend.

The gentleman I am purchasing it from has restored them for years but is no longer doing it, hence why I am buying in original condition. I will make sure I get plenty of photos of the existing cylinder reel, but I viewed the mower last weekend and I do recall there not being much meat left on the cylinder. I'll let you decide that when I get some photos however. Are the alternatives that I can consider just a full regrind and sharpen? He is putting a brand new bedknife on as well so I think that might be a slight motivation for the reel replacement.

In regards to the number of blades on the cylinder - I have asked him and he said it will be a 6 bladed cylinder. Now I understand the 8 and 10 blade set ups are better for mowing grass very short - but is 6 blades sufficient? I was concerned that it might not be enough after seeing 8 blade systems on most of the reconditioned mowers on here?

Thanks for your help.

Kenny.

Hi Kenny,

The 17" Scott Bonnar comes with a 6 blade cylinder reel as standard. Only the 20" Scotty has an 8 blade cylinder reel as standard.
The 10 blade reel is an after-market accessory.
The 6 blade reel can cut the grass short and is recommended for certain types of grass, and is the reel of choice on my own Scotty 45.

My advice, don't commit to the new reel until we have assessed yours.

Hi Kenny,

The standard 6 blade reel is ideal for almost all domestic lawns. There are aftermarket 8 and 10 blade reels available for the 17" machine but in the majority of cases there will be no noticeable improvement on a home lawn. For broad leaf grasses like buffalo that require higher levels of cut, the extra blades can have an adverse effect.

In a nutshell, the number of blades are matched to the type and height of grass being cut, 6 blades will do a better job on some, 10 blades on others. More blades doesn't equal better, they're for different applications.

I keep my own lawn to a high standard at fairly low heights and have 10 blade and 6 blade 45's. I can't notice any difference myself in the overall aftercut appearance between the two, but I'm not checking with a magnifying glass or measuring ball speed across the surface. I'll admit that when I bought my 10 blade reel that I was almost expecting a PGA quality green after the first mow but it wasn't to be



I absolutely agree with Darryl that there's no point in committing to a new reel yet. The biggest factor in achieving a quality cut will come from a sharp reel and bedknife that is correctly set.

Look forward to seeing some pictures and your progress once you get underway

Cheers, Michael

Hi all,

I'm now officially the proud owner of an SB45! I picked the mower up this afternoon and have already taken a few photos to upload. The label on the chassis says it is a Model 45 No. 18993. I'm not sure if this actually means anything to anyone but there is a photo of it below as well.

I've tried to get a few good photos of the cylinder. The gentleman I bought it off said it should have around 24mm of meat on the cylinder - does this sound about right? He is happy enough to make the new cylinder and will also replace the bed knife at the same time. What is everyone's opinion on the current cylinder?

The catcher seems to be in OK condition, few dings and a fair bit of surface rust on it. I'm hoping to eventually sand back and sandblast everything and get it powder coated similar to some of the other restorations on it. I don't really want to go too overboard, purely because I will actually use this mower weekly. But a nice fresh coat of paint to the chassis, engine and cylinder and a full clean up of the front roller, new bearings etc. is about all I am after.

I have attached several photos below - I think I managed to get everything that will be required. Let me know if any other photos will help.

Cheers,

Kenny.
















[img]https://www.outdoorking-forum.com.au/forum/uploads/usergals/2014/03/full-7786-15645-20140308_151147.jpg[/img]
[img]https://www.outdoorking-forum.com.au/forum/uploads/usergals/2014/03/full-7786-15646-20140308_151316.jpg[/img]

mate there is no rush to this just take your time and take plenty of pics for reference back.with a digital camera nowadays you can record just about every minute detail.and if you get stuck WELL you have a lot of help here.cheers

Hi Kenny,



Looks like a very nice base to start off with, well done . Could you please post the 'model type code' number stamped on the Briggs cowling (next to the fuel tank)? I'm curious when it was manufactured - I'm guessing late '79 early '80.

The reel needs straightening but you should get some life from it yet. If you do keep it, get the straightening done before you powder coat or paint it as it may wreck your nice finish otherwise

Hi Kenny,

And my on a good score there as well!
Our Inline Uploader will allow you to post 10 pics at one time, I have re-posted those that have not appeared in your post, here for you.

Re: your machine, it is a nice twin rail, Series 2 Scotty, The sprockets and chains look to be in nice serviceable condition....
The cylinder reel, in my opinion, is serviceable and has plenty of life left in it and does not need replacing....but I agree with Rolla, have the bent blades straightened prior to powder-coating and sharpening.
New cylinder reel bearings will probably be required, but they are not expensive and are essential in achieving the correct reel to bedknife adjustment.

The model, type and code may be hard to see as they are stamped into the metal air cowling of the Briggs and have then been painted over, and are adjacent to the carby intake manifold.

The Scott Bonnar decal on the chain case has been damaged beyond repair, but does confirm my knowledge that was white lettering with black edging.

The catcher will need some panel beating, but is in reasonable nick for its age.
The inner cutter clutch half has been replaced, and that is a good thing...they are a much better design.
The plastic thrust pad looks serviceable as well.

All round, a good buy, a machine that will restore beautifully, and will give you years of mowing pleasure.
Well done, mate!

Hi all,

Thanks for your great (and prompt) feedback. I've used the machine a little bit yesterday and it does run very well.

In regards to the reel - the gentleman I bought it off did initially mention I should get another 3 or 4 years out of it. He suggested keeping an eye out for older machines going for cheap that might have a better condition reel on them to replace it with as the new ones are quite expensive. However, the next day he gave me a ring and said he'd had a thought and he could have one made for $150. It sounded pretty good at the time so I gave the go ahead - was this wise? I thought it wouldn't hurt to have the new reel and bedknife on there and I can look after the rest myself.

I've attached a photo of the Model, Type & Code but it may be a little hard to see. To me it looks like:

Model: 80202
Type: 0879-01
Code: 81081003



Hope this helps.

So what is generally the first step in any restore? I'm in no rush but wouldn't mind laying out a bit of a plan of attack so when I do have some free time I can get stuck into it!

Cheers,

Kenny.

Hi again,

Deejay - I noticed you mentioned that the inner cutter clutch has been replaced with a better design - may I ask why this is? The only ones I have seen on here seem to be the 'cotter pin' single type of fixing. This one appears to have 2 screws on the drive shaft - is this any different?

Kenny.

Hi again Kenny,

Your engine was manufactured on the 10th August 1981, in Rolla, Missouri, USA.

I think in regards to the reel, you suggestion of getting a second hand original Scott Bonnar reel would have been in my opinion, the best option.

Making a reel from scratch is a job that requires specialist equipment in forming the twist of the helix in what is tempered high carbon steel.
have a look at the video here...you can see the blades being formed....


In my observations, your current reel will last you a long time if used domestically.

For a complete full restore, a plan of attack would be:

(1) Take a good series of photos of your machine with a digital camera for future reference in reassembly.
Order your replacement decals for engine, chassis and catcher.

(2) Using our videos as a guide HERE remove the cylinder reel and soleplate complete with its bottom blade attached, and have the blades straightened then powder coated then both sharpened.The engineer can supply and fit a new bottom blade if required.

(3) Split the cutter clutch and then remove the engine.

(4) Remove the cowling from the engine, degrease and thoroughly clean all parts of the engine and prepare for painting.

(5) Remove all chains and sprockets and rear roller assembly and any other ancillary equipment...(handles, clutch fork assembly etc) to achieve a bare chassis.

(6) Inspect chassis for any cracks, repair if necessary and then thoroughly clean and prepare for painting.

(7) Panel beat the catcher and clean and prepare for painting.

(8) Please post photos to this thread as you go along.

The inner cutter clutch half fitted to your machine, is a much better design in that it has a better fixing method to the PTO engine shaft. The grub screws are 90 degrees opposed and one secures the engine shaft key in its keyway, and the other secures the clutch half to the shaft.
The captive cotter fixing method is a design failure and suffers from damage by the key moving in its keyway and damage to the thrust bearing.

please keep us posted as you go along....

Well I was a year off on the engine but close It's an 8 cubic inch (127cc) with a pulsa-jet carb and from your pics it looks like it has the linkage type choke that engages when you pull the throttle control all the way back. Here's some specs..





You can get the engine decals with the correct white/silver/red/black on a clear background from the US via ebay and they're nice quality. I'm getting some numbers together to get some made locally but we're a couple of months off yet.


Love this video Darryl!

Hi Michael,
Yes mate, it is a great video, sometimes a picture says more than a thousand words.....
Here's Part 2 of that video:

Hi all,

Darryl - thanks you for the fantastic restore instruction you've posted above. I'm sure that I'll be on here asking plenty more questions but that is definitely a great place to start!

Also, my apologies for the post in the old thread earlier today. I knew that the thread was quite old but thought some members might have thread messages send to their email. The paint is the most confusing part for me at the moment. I understand no one has access to the correct SB45 paint formula but some people on here look to be getting quite close. Is there a verdict on the best way to paint the chassis and other parts? Is it worth getting it done professionally or is a spray can sufficient?

Thanks for the videos as well - VERY interesting.

Cheers,

Kenny.

Hi Kenny,

My advice with the painting would be to have a go yourself. It's not at all hard to get a nice finish if you take your time and prepare everything thoroughly. The only professionals that will do a significantly better job are auto painters (and they certainly will do a very high end job) but the price won't be cheap. If you paint it yourself, you can also touch it up down the track if you happen to scratch for example. I think you'll get more satisfaction from knowing you've done it yourself also

Ask as many questions as you need and we can guide you through the painting process.

Hi Michael and Kenny,

Michael, that is excellent advice...it is always a great feeling of achievement when you can complete a project with little help from the professional tradesmen...and creates pride in your own workmanship.
I am looking forward to seeing the progress pics as you go along, Kenny.
All good stuff!

Hi guys,

Thanks so much for all the support, I'm very appreciative.

I'm champing at the bit to get stuck into it - just need to learn a little more and have a couple of free weekends.

I would love to have a go at the painting myself - as you said it's much more satisfying when you can do it yourself. What is the best method to paint though? Can most good paint stores put a custom mix into a spray can for you or should I invest in a decent spray gun/compressor set up? I like the idea of taking the inside of the chain case cover into a store and getting the paint matched - is this the best option or has someone on here already identified the best standard colour?

The biggest concern I have is the paining of the engine. I'm yet to have a sit down and good go over it but not knowing too much about engines I'd prefer not to totally disassemble it if I can avoid it. The idea of using the Chevy Orange high heat paint from Super Cheap Auto seems pretty easy, I'm just not sure the best way to pull apart the engine and paint it. Also, the muffler seems to be too far gone to worry about painting (see above pictures) - should I just replace that with a new one from the spare parts section of ODK?

Thanks again.

Kenny.

Hi all,

Just wanted to let you know that I am still here - but unfortunately I haven't had the time to even start my resto yet! I've been keeping the mower cylinder adjusted and it cuts fantastic (I use it twice a week generally).

I'm finishing my final year of study and between work and study I don't have a lot of free time to be tinkering with lawnmowers. I anticipate getting stuck into my resto in November and will be on these forums quite a bit annoying everyone.

Deejay - I'm not sure whether or not you would prefer to close this thread and me start a new one in a few months time, or is it easier to simply leave it open? I still read these forums once a week, just have little time to contribute my own!

Cheers,

Kenny.

Hi Kenny,

Thanks for the update, and best of luck with your studies.