OutdoorKing Repair Forum Forums Restoring, Customising and Modifying Reel-Type Mowers Solid Deck SB 45 20"

I was perusing the interweb recently and came across this SB45 on Gumtree. I already have an original 45 17" that I was looking at changing out the reel for an 8 or 10 blade with a modified bottom blade for ultra low height of cut.

Unfortunately this mower has not had any love for quite some time. The reel was incorrectly adjusted and hitting the blade, the engine wouldn't run, the clutch thrust pad was destroyed, the catcher was rooted and some parts were missing including throttle cable and handle bar grips. But the mower had some potential and the things I wanted like the 8-blade reel and modified blade. I had recently also found a dead SB45 14" that I grabbed for parts, so the missing parts were not going to be an issue. I got it for a $120 which I thought was fair.

I got it home and had a play around to see if this was worth the investment to get it cutting to a level I was satisfied with. A quick assessment of the mower I can see it requires the following repairs;

- Reel and bedknife grind
- New cutter bearings
- New front roller caps
- New rear roller bearings as there is some slop in the rear roller.
- New PTO sprocket and bearing
- Potentially new chains, although I have a spare set from the 14"
- Clutch fork has some lateral movement, but still operates correctly

I thought I would do some quick servicing and see if this mower is something that I want to use. My lawn is a little pokey in some areas so I wanted to try it out.

-Disassembled clutch and engine from chassis. Cleaned carb, reset governer, replaced thrust pad and captive cotter with parts I had. Removed reel and soleplate, reset tolerance and gave it a backlap to clean up the blade and reel faces. Adjusted and lubricated chains, set the height and got mowing. It went pretty well, although the motor has a surge issue. No dramas, I have a GX160 that I scored from work that will be going in place of the aftermarket Tecumseh. Add a 3/4 inner clutch half to the parts list.

I will be doing a full disassembly of the mower over winter to correct the problems I have already observed, and I will probably do a soft resto of the appearance.




Can anyone determine when this machine was manufactured please?

Here are some more pics HERE

The best estimate we can make of the age of an SB45 is to use the manufacture date of the Briggs and Stratton engine and add three months or so. Your mower's Briggs has been replaced by a Tecumseh (a remarkably bad decision by somebody) so we can't estimate the mower's date of manufacture except from the fact that it is a one-piece-deck model and therefore an early example of SB45. Deejay will be able to tell you what that indicates in terms of years.

From your report, your mower was in average or better, condition for an SB45 of its age. The faults you found are normal, and should be expected in a second-hand SB45, even if it were a somewhat more recent model. Because you intend to replace the engine anyway, with a GX160 which is very much better engine if it is in normal condition, I suggest you don't waste your time doing anything to that Tecumseh beyond spitting on it in passing. The rest of the work in front of you should be straightforward, and largely covered by Deejay and Joe's videos. Hopefully you'll find it fun, and be very happy indeed to end up with a nice example of a one-piece-deck, 20", OHV Honda-engined, SB45. I suggest however that you post some better pictures of the mower that accurately show the condition of the paint. Repainting an early SB45 just to make it shinier, sounds like a move that would set the SB45 collectors baying for your blood.

Hi SimRice,

I would say at a guess your mower would be a late 1960's to early 1970's due to the colour of it. I'd say that it would've had a Kirby Lauson originally fitted and due to it failing at some stage and requiring parts which are pretty thin on the ground it had a later Tecumseh fitted and as Grumpy already mentioned a very bad choice indeed.

The solid deck unit which you have is without a doubt the best issue of the Model 45's as it didn't suffer top deck failure as did the later 45's with the twin rail design and especially on the 20 inch models they failed due to less strength in the rails as they were made from the same thickness of steel as the 14's and 17's were, thus the flexing of the rails was much greater and fatigue failure was on the cards right from the start.

What you paid for the machine is a damm good price (for a 20 inch unit) as once it is completely refurbished both mechanically and cosmetically it'll be in the $1,500 mark region, so all in all not a bad investment at all.

Cheers,
BB

Thanks for the input Grumpy and BB. When I inspected the machine we were haggling over the price and the guy selling it said the motor alone was worth $100! I told him he could keep it, as far as I am concerned it was going in the bin. It is a shame that the machine has lost the originality of the factory engine, however I think the GX is going to be the best fit for this machine.

The most important thing for myself is a reliable mower that starts first pull and cuts to a high level. I have seen some of the restorations on here that are unbelievable in the workmanship and finish; but I would be too afraid to use it in case I scratched it!

I'll post some better pics over the weekend that better depicts the current condition of the paint and other components.

I agree that the OHV Honda is the best available engine. The 20" SB45 is relatively uncommon and I don't recall the original engine - the 14" began with a Briggs and later unfortunately switched to a Kirby-Lauson, while the 17" began with a Kirby Lauson and later switched to a Briggs. Since you are going to use the machine regularly, IMO the best solution would be to fit the GX160 and keep the original engine in safe storage. However the original is long gone and presumably untraceable, so you can only do part of that.

Hi SimRice,

Firstly my on a great score for the price....well done mate!
What you have there is an early example of the 20" SB model 45, manufactured at the Thebarton factory in South Australia and would have originally been fitted with a Kirby Tecumseh HK30 3HP. 4 stroke engine.
It would also have the 3 section rear roller and an 8 blade cylinder reel.
Here's a pic...


I would like you to post some pics please of the inside of the chain-case so we can assess the condition of the chains and sprockets, also a close-up of the cylinder reel and bottom blade.
Once again, SimRice, a good score!

Hi SimRice, looks like a great base to start off with, well done I'm on the hunt for a solid deck 20" myself so I'm very envious!! Look forward to seeing your progress

Michael

Ok, so I stripped the whole mower down tonight to assess the components that I suspect need replacement.

I have some questions too.


Main PTO sprocket. Looks quite sharp on the teeth, so possible replacement?


Cutter sprocket, seems serviceable?


Main sprocket


Reel condition, seems true with no dents, but does need a grind


Overall appearance of the paint. Needs attention


In one of the roller casts, there is a ballasting. Why, and why only on the engine side?


The front roller caps and roller shaft are not serviceable. Have these been sleeved or was the brass OE.


Bedknife needs a refinish


The bedknife has been chamfered down on an angle. The tip is 1.5mm where as the bedknife on my 17" is 3mm at the face.

I am going to repaint this in a hammertone finish similar to the original, as well as some work to other components.
If a mod wants to move this thread to the resto page then do it, if not I'll just start a new one there.

I'd say the first three sprockets belong in the bin, the fourth one is marginal. The damage has been done by continued use of worn-out chains, which has worn the sprockets out of pitch.

I'll leave the rest to Deejay.

Hi SimRice,

Here are my observations for you:

(1) the engine driven sprocket (the small one) is unserviceable and will need to be replaced as will the primary chain.All other sprockets appear serviceable.

(2) Re: the drum weight in your rear roller, please read the complete thread HERE for the explanation.

(3) The brass bush was original manufacture; the end-caps were replaced by plastic in the Series 2 Scotty Model 45.

(4) The reel has plenty of life in it, but will need a spin-grind. The bed-knife however may need to be replaced....please ask you engineer/machinist who does the reel grind his opinion.

As you are going to do a restore on your machine, I will shift this thread to the Restoration forum topic.

Hi Deejay,

Am I correct in saying that the clutch sprocket is also pretty well shickered as those teeth look like they came straight out of a sharks gob ?, but yes that top sprocket is one of the sharpest tools in the shed that I've seen.

Cheers,
BB

Hi BB,

The clutch sprocket is the top one mate.
It is past its used-by date and IMO is unserviceable.

The lower ones are the cutter sprockets (2 in one, primary to secondary) are serviceable; the secondary drive sprocket is also serviceable.....I can take comfort that you will only have to purchase a new top sprocket and all should be well, if regular maintenance is carried out, chains replaced as necessary and regularly greased with a good quality grease.

Thanks guys for the input.

I stripped down an old 14" 45 that I had found for parts as the reel and blade were no good. It is also a solid deck so it is of similar vintage. I plan to use the best parts out of the two machines for the rebuild. Probably a bit sacrilege to do such a thing, but for a machine destined for the tip, at least it can go toward another Scotty living to mow another day.

I'll get some more done over the weekend and keep you posted.

Simon

Hi Darryl,

When I was referring to the clutch sprocket I was referring to the drive clutch (the large one) not the main clutch shaft as that one is so far gone its not funny. The large one certainly has lost a majority of its tooth profile.

Cheers,
BB

Yes BB, on second thoughts it does look as though it has had its day, but it is hard appraising sprockets from a photo...a lot easier in the flesh, so to speak.

Things are coming along nicely with the resto. I'll post some pics soon of the progress. One question I have is how does the top and bottom sections of the handlebars come apart? Does the thread holding the 2 sections together just need to be tapped out with a hammer?

I cleaned and polished down the handlebars. Can up fairly well, however there are some scratches.

I settled on Hammerite Dark Green. I played around with finishes and found that a foam roller gives a nice glossy hammer finish



I did some polishing of the exposed bright-work. I had a brass adjuster off another mower and decided to go with it over the cast original. Hopefully it's not too over the top.



I just gave the rear roller a quick coat or matte black. This will be used and used hard so I'm not overly worried about the rear roller.

Chassis coming together

Clutch

Cleaned and polished the cutter bearing holders

All the nuts and bolts have been cleaned and polished

I couldn't help popping the reel in to get an indication of how it will look.

There is still a bit to sort out with the mechanical's, but for now I am fairly happy so far with how it is progressing. I'll keep everyone updated

looking great , its coming up a treat so far

Hi SimRice,
And my on your brilliant work thus far...It looks fantastic, I really like that colour, especially on a solid deck Scotty.
Thanks for the tip on the foam roller for applying the Hammerite....that will help many future restorers.
Keep up the good work, looking forward to seeing your next progress pics.

Thanks guys!!

Being my first resto there are a couple of things that I'm not 100% happy with, however I think once its all together no one will see the minor imperfections.

I was lucky to have the wrecked 14" to pull parts off, as it saved me from buying new rear roller bearings, a clutch fork, clutch lever, clutch spring, thrust pad and it had the brass adjuster knob which came up a treat with some elbow grease.

I'm working on a cost effective new front roller with sealed bearings that can be fitted to this mower and 17". The shaft is cactus so instead of buying a whole new shaft and end caps for a substandard design, I am going in a different direction.

I got the colour idea from Jamskin's immaculate resto. I simply applied the paint with a brush, being careful not to over apply around the fixing holes and finished with a foam roller. I think it brings out the hammer tone nicely.

Simon