"Lawn mowers? On a GS/GSX website? The man has lost his mind, surely!"
Well, that might be true but small engine repair is a bit of a sideline of mine. And after a few years tinkering in the shed with many a dead lawn mower, I've had a few of the basic principles of engine health hammered-in to my slow-learning bonce. Maybe you need a little hammering, too? Read on...
In other parts of the world, it's known as 'B.O.Y.D.' ... ie. 'Bring Out Your Dead'. Here in Perth, Western Australia it's known simply as "the verge collection" that blissful time of year when everyone throws their junk out on the roadside for collection by the recycling contractors.
Naturally, one man's trash is another man's treasure and often thrown into the 'trash' category is the humble lawn mower. Usually for no other reason than the wretched thing just wouldn't start come spring, and the helpless owner doesn't want to fork out all that dosh at a small engine repair joint when for just a few dollars more he can have a shiny new piece of machinery instead.
So what's wrong with them? Often not a lot...
The first thing I do is spin the crank, to see if there's any compression. Because you can tinker all you like with a motor, but if it hasn't got enough compression then you're wasting your time.
Now why might a lawn mower engine have low compression? Well, mainly because they've been (i) run with a filthy or non-existent air filter, or (ii) the owner never checked or changed the sump oil and the thing got a cooking. A couple of mowers have merely had a loose spark-plug! That'll lose you compression every time, eh.
If the compression's good (and 9 times out of 10 it is), then I open the fuel tank cap and take a sniff. Stale fuel has to be, I think, the No.1 cause of these things not starting. Usually the fuel put into the tank toward the end of last summer was past its best to begin with; and then sitting for another 5-6 months has seen it lose all the volatile aromatics so essential for ignition. So I pull off the tank, rinse it out with some fresh fuel, and check that the fuel tap is OK while I'm at it.
Then just to be thorough, I make sure the carburettor is cleaned out; often they've got water inside, which isn't known for its combustible properties. Usually I don't have to use carbie cleaner fluid; a toothbrush with some kerosene or mineral turpentine does the trick. Compressed air is great for blasting out any jets, fuel passages, etc.
Now then, is there any spark? There are two ways to test for this. Firstly, you could ask one of the kids to come and hold the spark plug lead while you give the cord a pull, heh heh but that would be cruel and so we won't be using that method.
The other method is to unscrew the spark plug, rest it against the engine head, and give the motor a spin. Now then, no spark? Don't give up. First, clean the spark plug. To do this I like to use some carbie cleaner and a small wire brush, and blast the thing off with compressed air. Then a quick rub with some emerey paper in the gap to polish the electrodes back to nice bare metal. Then see if that's fixed it.
If not, try swapping for another plug. Because take careful note of this, folks: spark plugs can be perverse things indeed. They can give a nice healthy-looking spark outside the engine, but the moment they're under compression in the cylinder they can fail to do the job. The dodgy spark plug is one of life's little mysteries but it's quite common. In fact, a good number of brand new plugs are dodgy . So before thinking your plug is indeed OK, at least try and swap it with a plug from a machine you know is a runner.
Still no joy? It's time to inspect the ignition coil and lead. If the coil is shorting-out from the windings onto the body of the mower, you can patch it up with some epoxy glue. If worse comes to worst, you may have to buy a new condenser (they're only a few bucks); or on the really old mowers, pull off the flywheel and check the points.
Busted pull-starters are the other main problem. You can see how it happens. Mr.Suburbia pulls his mower out of the shed, never imagining the fuel is stale. And so he pulls that cord more and more, harder and harder. Then, just as his frustration is peaking, the cord finally breaks, the long recoil spring boings out of the casing, and that's that. In a fit of rage he stumps off to buy a brand new mower... which will also, happily, have fresh fuel in it.
Sooooo I've had to fiddle with more than a few busted recoil starters. But that's OK, plenty of spares from dismantled mowers grace the shelves in the shed.
"What have we learnt, children?"
So what's the Big Lesson common to all engines be it your 4-stroke Jap multi or your lethal little Victa 2-stroke mower? Simply this: fresh fuel, adequate compression, a well-timed spark, and you *should* have a running engine. If your motor won't run, it's time to ask which one of the afore-mentioned essentials is missing.
Most of these mowers and edgers I pass off to mates who, like myself, are too scroogey to want to pay silly money for a new piece of equipment. A couple of machines, though, I have kept for the time-being, simply because I love the beserk howl of the old 2-stroke Victas in particular. It's always amused me enormously that Victa put '75dB' stickers on the handlebars: a triumph of optimism, 'coz I reckon 750dB is probably more like it. I never start the things without hearing protection!
For identifying the old Victas, there was a handy PDF booklet available on the Victa website; but they took it down sometime in 2011. If you would like a copy, email me ('Contact me' link in the floating menu to the left there).
OK, let me introduce you to a few of the little beasties (click on the thumbnails for larger pics)...
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First cab off the rank is my pride and joy: the 160cc 2-stroke 1968 Victa I pulled off the verge around the corner. It was in a pretty sad state, but the fact the motor still had good compression was a big point in its favour. Apart from a good clean up and some repairs to the chassis, all it really needed was a new condenser to restore the spark. Usually the old girl starts third pull of the cord. Goes like the clappers and must annoy the tripe out of the neighbours. Urban lawn management at its best!
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Next we have a real bitsa. I don't know what that nice retro chassis is from, but the motor itself is made from three seperate Briggs & Stratton motors I had lying around as you can tell from the black, white and orange painted parts. With fresh fuel in the carbie it will routinely start with one lazy pull of the cord, and runs as quiet as a mouse and smooth as butter. Never judge a book by its cover. I recently gave this one away to a mate because I needed the room, and he needed a mower.
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Right then, here's my old Victa lawn edger, dubbed 'Little Lucifer' because of the hellish howl the thing emits from that 'bun' muffler. Why they call them 'mufflers' has me mystified; they seem to do nothing at all to muffle the noise. Of course they are really an expansion chamber to provide backpressure to the exhaust port, so that the little 125cc 2-stroke donk can run efficiently. The other thing I like about this machine is the spectacular rooster-tail of dirt it spews out ahead of you as you do the edges along the paths. Noice!
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Worth a brief mention is the 1978 Victa with the Briggs & Stratton engine, my usual lawnmowing hack. All you Holden (= Australian Chevrolet) fans out there will notice that it's got a 'Monaro' insignia. And that's about the closest I'll ever get to owning the iconic Australian car.
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I found this little beauty thrown on the verge the Rolls-Royce of the lawn-edgers! With no less than six wheels, and an amazing cantilevered system for raising and lowering the beast, it's an eye-catching machine. It was pretty-much all there, except for the fuel tank. Upon investigation it had a sheared woodruff key on the crankshaft, which meant no spark. Made up a new key from a piece of scrap metal, popped it all back together, put some fuel in the carbie, and the old Tecumseh engine started third pull of the cord without even a puff of smoke! So I cobbled together a 'new' fuel tank from an old lawnmower tank I had lying around, and mounted it on top of the engine with a generous air space between so the fuel won't get warm. Have given it to a mate in Rockingham who's been hankering for an edger for some time.
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Here's a blast from the past. I'm not sure of the vintage (1950's?), but I do know it's an old self-propelled 'Atco' mower with a 97cc Suffolk engine. Yes it goes just! The pull-starter broke to pieces years ago, so it needs to be started with a drill & socket on the end of the crank. The motor really needs a hone and a fresh set of piston rings, but the rings are pretty-much unobtainable these days. So she burns a bit of oil and the compression is flagging a bit. Recently sold it on eBay to make some more room in the shed.
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Well this one (below) was a bit more trouble than most, but I relish a challenge and the wretched thing succumbed in the end! With the plastic 'G4' carbie that so many of these later Victas have, it would start but just wouldn't run when you went to open the throttle. Tried this, tried that, but just wouldn't work. I decided in the end that the G4 carbie had to go, and I would graft on a cast aluminium carbie I'd filched from a late 60's Victa 'Mayfair' mower.
The first problem was that the newer Victa 'Power Torque' engine didn't have a suitable inlet manifold. No worries, I still had the old Mayfield cylinder block lying around, so I got out my trusty angle grinder, and cut the inlet manifold off the old cylinder. Err yeah, that's right: I cut it off with an angle grinder. Then I ground it down to size using the bench grinder, and bolted the inlet manifold on to the recipient motor.
That turned out to be the easy bit! With the new carbie grafted on, I now had to:
- chop off the existing fuel tank, as the fuel tap fouled the new carbie inlet;
- reconfigure the throttle cable connection & actuation;
- rig up a cut-out button for the ignition;
- pull off the old decompression valve and blank the hole with an old spark plug;
- mount a 'new' fuel tank further back on the chassis;
- reconfigure the air filter and snorkel set up; and finally
- mount another blade holder & blades, as the old one had large parts torn off it (!) and so it was horribly unbalanced.
Now then class, what we have just witnessed is the 'domino principle of engine modification'. It's all very well to think "I'll just wack a different carbie on," etc., but what this usually means is that a cascade of unforseen consequences is set into motion. Always think twice...
And the end result? See for yourself...
It mightn't be pretty but it goes like a rocket!
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Long after 'B.O.Y.D.' (see above for explanation) had come and gone, what did I spy but this little ripper unceremoniously dumped on a verge in East Fremantle a 1968 125cc Victa 'Mayfair'!
After a lot of fiddling with the carbie and installing a new condenser, she fired up and was running brilliantly. It was when I went to shut it down that I found out why they threw it away: the ignition short-out attached to the throttle lever was dodgy and for a few furious seconds there I became 'The Human High-Tension Lead'.
It therefore gave me great pleasure to rip out the original dodgy setup and mount a noice little red cut-out button there on the cowling. All is now well and once again I am spoilt for choice whenever I go to mow the lawn.
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How loving is my wife?! The other day (Dec. 2010) my good lady spied a mower dumped on the verge in a nearby suburb, when she was picking up the kids from school. In front of a crowd of gawking High School students, Kezza hauled the mower into the back seat of the car and brought it home for her man!
As you can see, it's a pristine old beast, complete with catcher. I first thought it might be a late 60's model, but the numbers stamped on the crankcase indicate 1972... which accords with the mower having a plastic petrol tank. All it had wrong with it was a split in the aforementioned petrol tank, but surprisingly I have managed to patch this up with a new glue for polythene plastic that has come on the market. The motor started second pull of the cord and goes like a ripper; a choice addition to the collection! Especially with the slogan "SUPER POWER" emblazoned on the front. Indeed: 160cc of toe-shredding, neighbour-infuriating, ear-bleeding POWER!
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Another one hauled off the verge (Sept. 2011), this time by my mate John. A 1963 Victa 'Consul 2', it's older than I am! It was all there but would it go? Cleaned out the tank, repaired the air filter, a few minor chassis repairs... and it fired up on the 3rd pull of the cord. It's now gone to John's father-in-law for regular lawn mowing duties. And it'll probably still be running in another 50 years' time, too.
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