OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Walk Behind Lawn Mower Frames Question On Scott Bonnar Cylinder Mowers Scott Bonnar/Rover 45 "Restoration"

Hi all,

Purchased a Scott Bonnar/Rover 45 Cylinder mower (5058) just the other day and she needs some work.

Before I go all in spending up $$$ keen to get your opinions. I am in for $50 thus far.

My first stop after purchasing it was the local mower dealer/service centre. I was advised the crack in the chassis along with a "bodged clutch housing" made it un-economical to repair.

So after doing a bit of research and stumbling on your website I discovered the crack in the engine mount/chassis is common to this model and not a death stroke as advised. (nothing a bit of welding cannot fix)

The clutch housing and captive cotter pin he referred to appears to have been replaced in later models with 2x grub screws as evident in mine;not a bodged job at all.

So after a bit of research I was feeling slightly less despondent about my new purchase. Time try her out........she cuts but not particularly well; those pesky weeds bounce right back up, and the mower it self shakes like a leaf leaving a slight Ali feeling in the arms.

Alas here I am, not a mechanical bone in my body but keen to try my luck on my first repair/restoration job.

Starting with the chassis as you can see from the paint work or lack there of it's definitely had a neglected life. A mate who owns a fabrication business will assist with sandblasting, welding a painting it.

I have seen Deejay's video on removing the engine, cylinder and sole plate but unsure on the rest of it. Need it stripped completely for sand blast and paint. I plan to have the cylinder sand blasted and painted as well. Should I include the sole plate and bed knife ? Should the cylinder and sole plate be powder coated or is sprayed ok ?

Will send these off for professional sharpen after.


The sprockets and chains are heavily gunked up and I plan to clean once I now how to remove them. (need to buy a 3 prong sprocket remover as shown in Deejays video; are these expensive and where can I source) (Is soaking in degreaser and cleaning with an old toothbrush ok?)

The rollers seem fine and the mower seems to "drive" without issue. Is it worth getting them blasted and painted or should this be avoided ?

It would be nice to clean up the rust of the drive shaft and repaint the clutch housing, can these be safely sand blasted/primed and painted ?

The engine is a Briggs and Stratton 80202 2324 01 88102603

Turns over after 5-6 cranks without any major splutter or smoke. Once warm idles constantly and doesn't lurch or bog down when in use. Plan to change plug, oil and air filter myself.

That's about it for now, I am most likely in over my head but keen to learn something new and you have to start somewhere !

Cheers

Chris

Hi Chris, and a warm welcome to the forum. Its nice to have another Rover-Scott Bonnar owner aboard, as we all like to learn new things and tinker here.

From what I can see in your pics; (and many thanks for posting good, clear pics) here are my observations.....

Your machine is a 17" model, manufactured at the Rover factory at Eagle Farm in Brisbane, sometime in early to mid 1989. Your 80202 engine was assembled on the 26th October 1988 at the Briggs Rolla facility in Missouri.

The cylinder reel has heaps of life left in it; it looks to never have been ground.
The chains need to be removed and soaked in degreaser to remove the gunk...just take out the removable links...just like the chain on your bike when you were a kid! Lol!
The 3 leg pullers you can get from an automotive shop and are not expensive.
The top (small) engine shaft sprocket will have to be replaced as it is badly worn, as is the double cutter sprocket, you would replace the primary chain as well at this time so as not to ruin the new sprockets.
All the other sprockets appear to be serviceable.

The grass deflector, deflector clamp screws and associated hardware appear to be missing, you will need to source new or second-hand ones as the deflector is what put the grass in the catcher.

All in all, a great score for $50.00....you will need to replace the cylinder reel bearings, perhaps the bedknife (bottom blade)...replace the double cutter and top sprockets, get a new primary chain, deflector and hardware, get the reel and bedknife sharpened; clean and grease the chains and mechanically you're in business!

As for stripping and painting, just follow my video to remove the engine etc and when you get to that stage, just post here and we will help you though the next stage.

Once again Chris, to OutdoorKing.

Hi Chris,

It will be worthwhile doing some pre-reading on your engine before you go much further.

Here is the Operator's Manual:
http://bsintek.basco.com/BriggsDocumentDisplay/flivAJX-nfBhU7y.pdf

Here is the Illustrated Parts List:
http://bsintek.basco.com/BriggsDocumentDisplay/Z6ntABVJ1DajI.pdf

The vibration you are feeling in the handlebars is not a good thing. It is most likely due to your cracked chassis rail allowing the engine to move up and down in a fashion that will further damage the rail, and may damage the clutch or the bearing on the engine output shaft. I suggest you refrain from using the mower until the chassis is repaired.

I also suggest that you carefully read this thread:
https://www.outdoorking-forum.com.au/forum/u...mp;Words=crack&Search=true#Post48231

Your machine came to you at a very good price, especially for WA, where prices for second-hand reel mowers are very high. It may be that the low price was for a good reason, and that reason may have been related to the condition of one or both chassis rails. This is not a fatal fault in the SB45, unless you are over-charged for repairing it, but it is a very serious condition and needs to be dealt with properly, as explained in the thread above.

Hi all,

Thanks Deejay and Grumpy for your assistance, Deejay your videos made removing the engine, cylinder and bed knife easy!

Apologies in advance as I am no doubt naming the components incorrectly.

Hoping you can provide some further guidance removing the

"Front roller"
"Small engine Sprocket"
"Large Sprocket"
"Medium Sprocket"
"Clutch Cable"
"Drive Shaft"
"Rear Rollers"

Also the cylinder bearings aren't coming off, can these be "wedged" of




f with a screwdriver ?

I have attached some pictures so you know what I am referring to.

Once removed I will be sending the following off for sand blasting and powder coating

- Rear Rollers
- Chassis
- Front Roller

Can the drive shaft and clutch assembly be sandblasted and painted or is it better to hand sand and spray paint ?

Hi ChrisUzA, I have been busy with family stuff all day, but I will give you some guidance in the next day or two, you will find it all easy...Don't for get to take plenty of pics along the way....It helps you to put it together again!.

Hi ChrisUza,

In your above posting you state you are sending off the Rear roller, Chassis and front roller for powder coating.

I would strongly suggest that you do NOT powder coat any of the above mentioned items as Powder Coating is Hygroscopic and once ruptured, scratched or pierced in any way allows water in under the surface and then the cancer begins.

Have a look at your chassis, it is basically covered in rust and that's not just the exposed bits and pieces but if you started pulling on the edges of the current powder coating you will find that the rust just keeps on going. (only the Rover produced 45's are powder coated, Kermit Green and Rover Red units)

The rear roller coating will be rupture on the first outing and as such there is absolutely no point in doing it. If you feel strongly about it then just paint it and all the high points of the roller will wear off instantly. Personally I wouldn't go down that road in the first instance.
The same for the front roller, if anything just paint but the moment you go over any cement the surface will be damaged.

And the chassis again I would sandblast especially since it's been powder coated previously and simply paint with an enamel base paint.

The thread Grumpy has given you the link to regarding cracks in the chassis is in fact one of my units from some time ago now and to this day it has been put aside as there was so much involved and I wasn't going to pay someone a full wage to do it correctly, now if I had someone that was skilled enough to do it for a carton etc. then that would be a different story. I think you'll find that if you scrape back all the powder coating around the motor mount area you'll find that there will be a lot more fractures revealed, much the same as was the case on that chassis I have. Rest assured I will have it repaired but only at the right price as it doesn't take long to blow costs out with paying someone a full quid for their time. I can see in some of your sprocket photos that some will require replacing and the cost will probably blow you over so don't reveal those to your wife LOL !

Don't for a moment be put off as the cost of a new machine is out of this world and you can do the job if you are very frugal at a fraction, but taking the good advice from this forum will be crucial as we don't have any dreamers on here at all, just genuine enthusiasts that have a real love for the Scott Bonnar's

The moral behind the story is to have fun and learn from it and then reap the rewards of your labour, and then you'll get all your neighbours wanting one, next minute you'll be building one for each of them, as is my case. HA Ha !

Cheers,
BB.

Thanks BB

A mate will be repairing the cracks/fractures but I will be paying rack rate for the sandblasting and powder coating. I haven't seen his work (golf buddy) but he has owned a fabrication business for 25+ years so he must be doing something right.

Appreciate your feedback on the powder coating, this confirms the advice of another mate who advised against powder coating and recommended just painting by hand.

Quite happy to brush it myself as this will save some $$ and possibly just pay for the cylinder to be sprayed, thoughts on this?

Deejey mentioned the small engine sprocket and the double cutter sprocket along with a new primary chain. (There is a local retailer in Perth seeling for
$59 - Small engine Sprocket
$92 - Cutter Sprocket
$30.95 - Chain

Do the other sprockets look ok ?

I am hoping the above plus some new stainless nuts and bolts to replace the severely rusted ones along with 2 new cutter bearings will be all that's required.

Should have me all in for about $400 tops.

Great thread - pls do keep us posted on progress.

Cheers Hooksey