As someone who only discovered this site yesterday I am a bit reluctant to dive in too deep with too much info, but basically I have managed to come by a Scott Bonnar 14" Model 45 that I intend to use to manage my lawn. Initially I had planned to simply get it serviced and running. But after having read through the pages here and scrapped away some of the dust and gunk from the machine, I think it probably deserves a bit more than that. I have a very basic understanding of machinery, but have never really got my hands dirty, so am a little nervous about the project. I am certainly not up on the lingo, so please forgive me if I cause confusion when describing something or asking for help.
Given what I know of its history (was used on a suburban yard for about 5 years (circa 1970-75) and then put in a shed until this week) and having had a good look at it and comparing it to pictures I found in these pages, I am very confident that it is entirely original and in pretty good nick. The engine turns over when I pull the cord, the throttle and clutch cables are intact and functioning. The catcher only has one small ding in it, and the sides of it and the mower itself are not very badly scratched. The cylinder turns easily and smoothly as do the rollers at the front and the back. A lot of the original decals are in pretty good condition. There appears to be no cracks to the external structure and under the oily gunk the paint looks like new. It does have a lot of surface rust away from the oily gunk, but nothing has rusted through. Given it has only had about 5 years of active service I am hoping that there has not been too much wear and tear and that very little will need to be replaced.
My one big concern with embarking on a project like this is me. I do not really know where to start, and I am keen not to cause damage. As an example, I was keen to get the chain guard off this morning and have a look inside, but the screws that hold it on are pretty stuck. I have sprayed a bit of WD40 around the screw heads but do not think it will do much good. I do not want to damage the screw head (my biggest screwdriver probably does not have a big enough tip either) but know that it is going to take some elbow grease. I guess I do not have the experience to know how hard to push, or any of the tricks that make what seems difficult, straightforward. As such, I think that I will be on here from time to time, reading through threads to get some knowledge, and asking questions of those that do have that experience and are keen to help.
At this stage I plan to get the bloke who services my rotary mower over to have a look at it and see if we can start it. I will take his advice on what he thinks I should do from a mechanical point of view and then start to make decisions about the cosmetics (I think it deserves to be brought back to its former glory, but time will tell).
I have taken some photos and am keen to share if people are interested. It is a 14" Model 45 with the 2.25 hp Briggs and Stratton motor and is the 14" model included in the "New Breed 45's" catalogue that I came across in a thread here. From what I learned on these pages yesterday, I am pretty sure it was made in January 1969 (the Code stamped on the side of the motor is 6901153 I think - there is a fair bit of rusty gunk there but he first 2 numbers are definitely 69). The model number is 60202 (I think) and the type number seems to be 0198 01. The plate riveted to the base that the engine sits on identifies it as mower number 45 05915.
Anyway, if anyone has any tips off the bat, I would be very pleased to hear them. Thanks for a great forum too. From the bits and pieces I have read, it sounds very civil, and provides and ton of info.
Sounds like you have a very original little 14". Absolutely attach some photos. We can also then give you our opinion as to what needs attention and what may be left alone.
In spite of appearance, they are fairly simple machines. If you are going to go for a full "restoration" there will be a list of tools you will need, no exceptions. But most general maintenance can be done easily with tools you're likely to have at home already.
I have a 14" from 1968-1969. She was ugly, but solid when I got it. I had planned to just do a "little tidy up" but we all know how well I managed to stick to that idea! I've popped a photo up to perhaps help with inspiration. It has been modified slightly and I have used decals from an earlier machine as I thought they suited the colour scheme better. She's no show pony, she gets used every three or four days in summer. I replaced the engine on it even though I didn't have to. Because, well, Honda.
This forum is a wealth of knowledge. A lot of members with a lot of experience. I enjoy my time here and I hope you will too.
I don't collect mowers. I just require Multiple Mowing Solutionsâ„¢.
She's a very pretty little workhorse. I am hoping mine gets somewhere near that attractive.
I was pleased yesterday arvo when I got the chain guard off. The WD40 did the trick and the screws came out quite smoothly in the end. I will await an expert opinion, but beside some 50 yr old grass clippings, underneath looked like new to me.
While I wait for a mechanical assessment I have started trying to remove the coating of dirt and rust. The catcher has come up OK, i think the chrome handlebars are going to need sandblasting and re-plating. Anyway, a few pics are below (i hope).
Wow, Boregy, you've got a proper little find there. I agree with your initial assessment - it's done very little work. I would almost think a quick lube of moving parts and an engine oil change would be all you need to get cutting again! That's in amazing original condition and under the chain cover is brilliant.
The only things you can't really replace on these today are the rear rollers, bed knife carrier (sole plate) and in your case, the clutch. They are all made of cast iron, so don't go dropping them or running roughshod over bumpy, solid surfaces. (You can get replacement clutches, but they're alloy.)
I don't collect mowers. I just require Multiple Mowing Solutionsâ„¢.
I have had a bloke here to look at it. He cleaned the points and got a spark, but could not get it to run. He tells me that there is a lack of compression. I am wondering if this is an issue others have faced, and if so what might be causing it? I understand that it could be a range of things - just wondering if there is a common cause on these Briggs and Stratton engines?
It sounds a bit like the 'bloke' may not fully have understood how to check compression on older Briggs engines, of the 'Easy-Spin Starting' era. It's not fully explained in the current edition of the Briggs Repair Manual that covers these older engines, either - the P/No CE8069 one.
There is a scanned copy of the original hard copy Briggs Service Manual from that era available [free to subscribing members], in ODK's Briggs Manual Download section.
That is, with the cowling off, to spin the flywheel backwards, and see if there's sufficient compression for the flywheel to stop, then 'bounce' forwards slightly.
That said, it was also very common for the exhaust valve head to wear down, until it ran out of tappet clearance.
Cheers, Gadge
"ODK Mods can explain it to you, but they can't understand it for you..."
"Crazy can be medicated, ignorance can be educated - but there is no cure for stupid..."
It could be the carby, a kit to replace the diaphragm etc would not go astray, I have had a number of these engines apart and it is almost always the carby, the diaphragms get stiff over time and do not operate as they are designed to do. I read somewhere that it is advisable to do this every 12 months, an overkill but does indicate that it is important, the diaphram is the pump that gets the fuel up to the engine.
I plan to take the head off tomorrow and have a look at the valves. If the valves are OK I will replace the head gasket and rings before I put it back together anyway. Sounds like I should have a look at the carby too, even if the valves are OK. The carby makes me nervous - looks fiddly - but I guess that's how you learn.
And thanks again to Gadge for pointing me in the direction of the manual. I think it would have taken some finding otherwise.
One general question. I have looked around for parts, and see that most things come in a genuine Briggs and Stratton option, or a cheaper option. Is there any difference in quality, or only price?
That's not a bad idea either. If the little diaphragms have dried out and cracked, they'll be useless. Pretty simple to replace. As mentioned, don't lose the little bits!
I also had a problem where tiny pin holes allowed the fuel to leak from the pickup bowl back into the tank proper. Unless you had started it recently, you had to pull it over several times before it picked up enough fuel to allow it to run. Unlikely in this case, I reckon, but something to consider.
I find with spares, if they're reputable, you'll be good to go. I've had no problems with the likes of GA Spares, Bynorm and Stens. You can pick up HEAPS of old Briggs gear from the US on sites like eBay. Unfortunately, shipping is usually the most expensive part.
I don't collect mowers. I just require Multiple Mowing Solutionsâ„¢.
Have had the exact same prob Mystyler - except this was a bigger pinprick and a real pain - would run sometimes, and occasionally wouldn't. Still have the tank as I was thinking how to patch it as the tank is otherwise mint.
I got into the garage early this morning and did as Gadge suggested with regard to spinning the flywheel backwards. There was no bounce at all so compression does seem to be a problem, but I will still look at the carby.
I took the head off and was surprised to find some mouse sh!t under the head (but outside the cylinder). I turned the flywheel a few times and there was some movement in the inlet valve (or the valve I assume is the inlet valve) but nothing in from the exhaust valve. But after a few more revolutions there was some movement and after a few minutes both valves were opening and closing. As I mentioned at the outset, I am no mechanic, so would not mind an opinion on whether or not they are opening far enough (hopefully I can put up a video) and if there appears to be an issues with timing - it looks OK to me and I can think of no reason why anything would get out of sync, but always appreciate the opinion of someone who knows.
Any tips on how much cleaning the cylinder, valves and head require, and how to go about it, would also be appreciated.
I don't think the timing would be a problem, if you're the first one to open it up. I would hazard a guess that you are!
I used a soft (brass, I think) wire cup brush on a drill to clean up the head. You can use the same method on the piston and valves if you like, or you can use a plastic scraper or nylon brush. DON'T go too hard around where the valves sit! If you change the shape you'll need to reseal them. Make sure the piston is at the top of its travel and the valves are closed before you start cleaning. Lightly blast any loose stuff away with a bit of air directed across the assembly, rather than straight down at it. There are also solvents you can buy to help you out. But most of that looks like it would come off without too much effort.
Sounds like you had a stuck valve. It is still a bit tricky to tell without being there in person, but they look like they are functioning normally in your video.
I don't collect mowers. I just require Multiple Mowing Solutionsâ„¢.
