OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Walk Behind Lawn Mower Frames Question On Scott Bonnar Cylinder Mowers 7 year old SB - Rover 45? Should I buy it?

Long time no posties. But I know this is the place to come to for expert help and advice.

Some might remember I have an old model 33 which is about 50 odd years old now. I bought it just over 2 years ago for about $300 and it has served me well since. Unfortunately it died today and I don't have the time to repair it myself. The engine has seized (old Tecumseh/Kirby). I am not sure whether it is worth spending money on a new engine as I have heard it is hard to source parts for if something else goes wrong?

I was thinking of investing in a 45 instead and maybe down the track, get the 33 fixed up and sell it or maybe restore it if I can find the parts?

Anyway, I have found a 45 Rover at a fairly good price ($500) and the guy selling thinks it's about 7 years old so quite young but the clutch isn't working properly. He thinks the blades stay engaged sometimes when they shouldn't be. Is this an easy/cheap fix? Is it worth the punt? The mower looks in OK nik otherwise going by the pics. I will be having a look at it this weekend.

Another question - Are the older model 45s better than the newer ones? What are the best 45 models in general - age wise I mean?

Thanks in anticipation.

Hi again wazzbat, and welcome back to the forum.
You have posed some good questions here...I'll do my best to give you some answers.

If you intend to restore the Model 33 down the track and keep it all original...then sourcing a replacement Kirby -Tecumseh engine would be the way to go...repairing your engine could be difficult because of shortage of over-size parts that would be required in case you have to re-bore the cylinder....Until you pull it down, you won't know what damage has been done...
2nd option is to replace the Kirby with an older 3 HP Briggs (as used on the Model 45) but you would lose originality. Selling it as is, would be another option.

As you say, the Model 33 is getting long in the tooth as a working machine and a Model 45 (all parts still available) is in my opinion a better option long term.

Now to the SB Model 45 versus Rover 45...some say the original Scotties have a better build quality than the Rover; but never having owned a Rover, I can't comment other than to say that some smaller items were changed when Rover took over SB...the double race engine shaft bearings for example.
The Model 45 was first introduced in 1968 and featured a solid engine deck...whereas the later Scotties (my model) have twin rails (as does the Rover). Some say the solid deck is better, less prone to cracking due to vibration...mine however, is still fine with no cracks.
I prefer the later 70's models myself.

I think that $500 for a 7 year old Rover 45 is a good buy, but before you do decide to purchase...please post the whole string of numbers on the Briggs cowling (or elsewhere) so that we can determine the exact age of the engine and give us a rough idea of the age of the machine. Don't forget these machines were $1800+ when new.
Clutch problems are a relatively easy fix and we can step you through the repair procedure, if necessary.
Looking forward to seeing some pics if you can take some on the weekend.

Hi again Darryl

Thanks for the reply.

I rang a mower repair shop today and they told me that the clutch problem could be either 1.) A simple adjustment. 2.) Fix the clutch (roughly $150 with labour) 3.) Clutch has damaged the engine shaft and will need to be replaced (roughly $500).

Problem is, the mower is a good 90 minute + drive away and the guy was going to bring the mower with him to Perth this weekend for me to have a look at. He doesn't want to bring the mower unless I am serious. After the call to the mower shop today, I'm not sure if I should bother? My luck, it will be an expensive fix up. I will see if I can get the engine number?

But if the mower is only 7 years old and everything else is in good working order then $500 might still be a good buy even if I do need to replace the clutch and engine? But then again, there might be better buys around. Mmmmm? What to do?

I'm leaning towards taking the 33 into a local shop and seeing if the guy thinks it's worth putting a new donk on and in the meantime keep an eye out for a good value 45.

Then again, if I get another mower (45) then I can spend some time stripping the 33 down and seeing what can be done? I would love to have an all original (or mostly original) Model 33. Arrrgh! Too many options????

Anyway, I'm off to try and revive the old 33 for now.

Thanks again for your comments Deejay.

OK - Update

Just came back from having a look at the old girl. After a change of oil and a bit of TLC, I have managed to get her purring again. And then another change of oil which I might do again in a week or so too?

Anyway, now I have the engine running smoothly again but I can't get the blades to engage? I had a bit of a fiddle with the clutch but I can't get it to work? If anyone has any ideas on how to get my 33 going properly, I would be very grateful to hear them.

Just got a message that the 45 I was looking at has been sold already so that's a no go now.

Cheers

I haven't seen a model 33 but if it is a belt clutch I would guess it has a belt tensioner that acts as a clutch actuated by a cable or leaver. If it is it might be as simple as adjusting the tensioner so it is closer to the belt or maybe the belt has stretched too much and needs replacing.
Maybe if you can post a pic of the drive system.
Cheers Andy

Thanks Andy. I will try and get some pics later today.

Not too good with names when it comes to mechanical stuff but here goes...

There is a lever that pushes the cone shaped thingo (I thought this was the "clutch") towards a round plate on the driveshaft. You are right in that the blade is belt driven but I can not get the part of the shaft that engages the belt to turn so the problem is happening at the cone/clutch before it gets to the belt. Hopefully that makes sense?

The clutch part of things isn't what I imagined. I always thought that the end of the cone would push against the plate attached to the shaft and would grab via a cork plate? I couldn't see any cork? I'm not sure how the clutch really works on my 33? Exactly how is the clutch meant to engage with the shaft?

I vaguely remember someone telling me that the 33 clutch is metal on metal so how could I fix it? Does it sound like this can be fixed?

Thanks guys.

Hi wazzbat, the clutch on the Model 33 is the same virtually as the one on the Model 45. The cone in the middle is all metal and moves out to engage the outer clutch housing whose inner lip is also cone shaped and has a cork lining glued to it that drives the clutch shaft. Pretty simple stuff!

Push the cone in, no drive, let it out (it has a spring internally) and away you go.
These probs are easily fixed, and with our help you will be able to do it yourself.
The cork lining can be replaced if necessary and is available in the online store.

Thanks again Darryl. I think I will need a new cork? Will have another look later on. Cheers.

Hi again wazzbat, It may only need adjusting to let the cone out further to engage, that is done by the screw and locknut under the clutch handle.
Please let us know how you get on, mate.

I'm at work ATM so I can't take a look but I just rang the local mower repair shop and spoke to the guy who helped me get the engine going again and he said that the 33s don't have a cork in them. He said he can come and have a look for $20 but said if it's buggered, it can't be fixed. He did tell me to try adjusting the lever a bit so I might have another play with that.

It sounds like I might need to let the screw out. Bit more? Is it a fine adjustment or is there a fairly big range it will still work in? In other words, should I be trying to adjust it a tiny bit at a time?

Thanks

Good news!



I had another play around with the clutch lever screw thingo and at first, thought it was going to be a waste of time but then, for some reason, the clutch started grabing? I was doing all the adjusting and checking by turning the shaft/clutch housing by hand and I don't know what I did but all of a sudden, it grabbed. I had to tighten the screw a little to get the blades to disengage again but now it's all working great. And the engine is running better than ever!

I think I might change the oil a little more often from here on in. Once every 2 years obviously doesn't cut it.

One more thing though - When I was playing around with the clutch, I noticed that the shaft which drives the belt/blades (clutch drive shaft maybe?) was able to be pushed in and out about 10mm. It felt to me that this shouldn't be happening. It was like whatever holds the clutch drive shaft to the engine shaft was loose? Like I have stated previously, I don't have much of a clue about engines and the like and I can't afford the time or money to be pulling things apart to find out how they work. I'm hoping this is an easy fix if it is a problem/potential problem?

Hopefully I will be back here in the near future getting advice on where to start in restoring my old 33. I was thinking today that it looks in really good shape considering it's 50 odd years old. I would love to have it restored properly.


Thanks for your help Darryl and Andy.

Hi again Wazzbat, if the engine cutter shaft is loose, it may pay you to pull the clutch apart at some stage, to ascertain what is actually happening inside...in that case please post some pics of the internals, so that we may give you some advice on how to proceed.
Glad to see that you got the old girl running again!!

Thanks Darryl. I think I might wait until I get myself a 45 before I start pulling anything apart on the 33. Just in case I can't get it back together and going again. But when I do, I will be sure to post some pics.

Cheers

No probs wazzbat, good hunting for the 45.
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