OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Walk Behind Lawn Mower Frames Question On Scott Bonnar Cylinder Mowers Phase 2 of SB45 Overhaul

Hi Jarrad, she's going to look like a bought one when she is finished mate....well done thus far.
BTW, I agree with Grumpy on the condition of the cutter sprocket...the chain will be stretched as well, and will require replacing.

Just went out to the shed and had a look at the two chains, that run on the cutter sprocket. If you hold them on edge, they look like there smiling at you. Guess that is not so good.

As for the sprocket, yes it is worn but I didnt think it was too bad. The larger sprocked on the cutter sprocket assy is visably worn from a loose chain, but the teeth I thought were still usable.

The top little sprocket I thought was quite good.

Deejay or Grumpy can you please explain for me what you are looking for to determine that a sprocket is worn.

For $55 for 2 new chains from mower shop, dont really want to destroy them. However 415 and 06B type chain is quite common, has anyone tried to source it elsewhere?

Ohh and cheers for the tip for soapy water and steel wool for the handle bars. Look a lot better after that and a polish with some Autosol. Only some minor pitting.

Here is a pair of teeth from your larger reel sprocket:


You can see that on the left side of the recess between teeth there is a very steep slope, but the other side has a much gentler angle, due to the tip being worn or broken away. This happens because the rollers in the chain are further apart than the teeth on the sprocket, so they wear away the sprocket to match the pitch of the chain. As wear proceeds further the steeper side will become undercut, then the tip of the tooth will fall off. When the tips are gone most of the way around the sprocket, it will start slipping.

Here is a pair of teeth from your smaller reel sprocket:


This time you can see that the teeth have splayed out on both sides, resulting in the height of teeth being reduced. On the left side of the left tooth you can see some secondary angling of the tip of the tooth. This reduces the height even faster.

Some better pix, So it wears the same as a motorbike chain and sprocket. Just harder to see without my glasses.

So regular checking and replacement of the chains would save in the long run

The problem is that if you keep running the worn chain, you'll ruin the large sprockets as well as the small ones. They are likely to be expensive. If the large ones are worn already, you might as well run the whole thing as it is until the sprockets go bald, since you'll have to replace them all anyway. The aim of the game is to keep from ruining the large sprockets, if possible.

Of course if the previous tenant had replaced the chains in a timely manner, the damage to the small sprockets would have been delayed a long time.

Hi Jarrad, owning a Scotty 45 is owning a piece of complex machinery that needs a routine maintenance schedule to keep it running sweetly and prevent wear to the moving parts.
Lubrication is also very important for the sprockets and chains and will lengthen their life greatly if applied on a regular basis.
For my routine maintenance schedule....Click HERE
This guide also includes changing the engine oil which is most important on a regular basis....as a very wise old man told me once..." Oil is cheap....Engines are expensive!"

Jarrad, I'll make a specific suggestion with regard to the chains. There are two ways chains wear out: lack of lubrication, or dirt sticking to the lubricant and making a form of lapping paste. The latter is usually slightly more disastrous than the former.

The easy and effective way to look after the chains is to have a regular service schedule that includes washing the chains and sprockets with solvent, drying them, then oiling them. In the old days this was done by taking off the chains, washing them in a kerosene bath, blowing off the kero with compressed air, and oiling them up before putting them back on the sprockets. These days it is probably more common to leave them on the machine, blast off the oil and crud with a degreaser spray, dry off the degreaser with air blast, then spray on new lubricant. Both systems can work well or badly, depending on the operator.

Hi Jarrad and grumpy, I have found over the many years of operation of my Scotty, a good quality grease is the way to go with the sprockets and chains....rather than oil...In fact all mine are original and have never been replaced. I will however have to replace the small engine sprocket some time in the future, as it is showing signs of wear...but it has done its job for 30 odd years....
The design of the chain case cover prevents dirt and crud getting in there and with regular maintenance should not pose a problem.

Thanks for the advice

Big sprocket looks quite good. The excessive amount of grease in this machine may have done some good.

Just ordered small and cutter sprocket from Outdoor King store. Cheaper than these parts were avail locally. My best price in WA was $53 for the little one and $92 for the cutter sprocket, plus $20 p&h

Goin to order chain locally as can get 3 meter lengths for $25. Just need to cut to length. Even considered making own sprockets, but not worth it given the two were only $100. That wouldnt cover the time it would take me to machine them.

Hopefully will get the chassis, chain cover and grass deflector into green paint before end of weekend.

Few more progress shots

Got the chassis painted green before work on Friday, so spent some time putting it back together over the weekend. I still need to paint the handle bar trim and grass deflector. The colour came up pretty close to the original as I got the paint shop to match it.

Waiting on sprockets, chains and I need to freshen up cutter assambley. But all going well it should be back together for the weekend.

Will give the catcher a freshen up next, so it all looks like a new mower.

I havnt worried about re-painting the rollers as this mower will be used.

Looks sweet Jarrad. Very nice.

Yes Jarrad, she's coming along very nicely...she will look like a bought one when she is finished. Well done mate.

Looking fantastic Jarrad,Love the green.Very well restored,Both Beautiful and functional.Nice to see your hard work will be used as it was intended not just as a display piece as so many of mine end up,lols.Well done!!!

Thanks for the encouragement.

Made the decision the send the sole plate in to mower shop today, for new bedknife. Plus the cylinder is going to get a sharpen as well. Put them back in on the weekend and was not happy with the setup, so rather than pull it out at a later date, Im getting it done now.

I have made up a new set of chains, but still waiting on sprockets.

Because I purchased some full lengths of chain. I have a complete set of chains for sale. Plus some Primary Chains that go from top sprocket to cutter sprocket. Asking $50 for the full set as pictured and $20 for Primary Chain only.

Very smick Well done looks new, now your missus might want you to sell to make $$ LOL

New sprockets turned up today. So took a break from the jobs I should have been doing to get the mower back together. I used some good quality grease on the chains, so will see how it goes.





Im going to strip the catcher back now, for a fresh coat of paint. I have got a late model rover decal to go onto the catcher, which will match the handle bar decal.

Having used the mower now, It is very different to the old red SB that I used to have. This later Briggs engine has heaps more power and is quiter than the old orange one.

However in my opinion the different shaped SB handle bars seem to be more comfortable. As they are lower than the rover bars.

Anyway cheers for the help and when I get the catcher painted up. I will get her out in the sun and take some final photo's.

Hi Jarrad, and on a fantastic job....She does look like a bought one!! Well done mate.

Hi Jarrad,

I've PM'd you re your chain sets

Andrew

Made a start on the catcher today.

It's hard to see in the photo, but the lower front of the catcher has had a few beatings in it's life.

I have panel beated out the major dents and got it as good as I could. Ended up putting a thin layer of filler over the area. The finish will have some ripple in it, but no major dents like before.

Im pretty careful with my mowers and there are no obstacles in my lawn, so it should stay in good condition

Hi Jarrad, are you happy with the performance of the scourer type paint remover attachment for the angle grinder? Looks like it did a fine job. Is that all that you used & how long did it take to remove the paint back to the metal?
Cheers Ross