That’s my dad at considerably younger than my present age, proudly mowing the front lawn of his and my mother’s recently-acquired house in suburban Philadelphia some years before I arrived. He’s using a Sears Craftsman 20″ push mower, a newish ’69 or ’70 model, with magnesium(!) deck, Foldamatic handle (you loosen two big red plastic wingnuts and fold it yourself; that sound anymatic to you?) and a Sears-spec Tecumseh engine, probably an LAV-30, with a vertical-pull starter.
One just like it showed up on Fleabay a couple years ago in remarkable condition:
Right up there with the charcoal barbecue grille and the electric garage door opener and the other tasty fruit of the postwar suburban boom—atop the heap, really—is the rotary lawnmower. Whether in Levittown or Homestead or Pleasant Valley or Southmoor Heights or Vista View Estates or The Wuthering Twin Oaks Bellevue Mews at Bel Air Manor, your suburban house almost certainly had a lawn. And as you didn’t want to incur the scorn of the Joneses or risk the wrath of Mrs. Kravitz (when she wasn’t selling Chevs) and the rest of the Homeowners’ Association busybody brigade, you strove for lawnly perfection. That meant keeping it green, weed-free, and “manicured”. None of this just happened to happen; wanna spur an economic boom? Accustom people to thinking of themselves as “consumers” and make sure every suburbanite buys stuff that’ll require perpetual spending. Like a lawn big enough to warrant the purchase and weekly use of a power mower and its fuel and upkeep, and addicted to water—better look into a built-in sprinkler system; the Joneses already have one—and chemicals also (b’gosh!) available for purchase.
And purchase did they ever…
Quickly upon its mid-1950s advent, the rotary mower fairly shoved the reel type to the margins of the market. And aside from your house and the car(s) in your driveway, what better billboard for your cashflow—the Joneses may well be your neighbours, but you’re theirs, too—than a machine that draws attention to itself by making noise as you walk it round the yard in swaths about 20 inches wide every week? No real place for tailfins or a Breezeway backglass on a mower, but no matter; there was still puh-lenty of This Year’s Modelry to be done. In terms of how well a mower worked, how versatile it was, how easy it was to use (or how cheaply it could be built, but shush about that til later) some of the changes made substantial improvements. Others were either the wrong answers, or the answers to wrong questions.
Such a one was the windup (or “impulse”) starter. In the late 1950s they were the very latest thing. The idea was to turn a crank to wind up a heavy spring, then trip a release mechanism so the spring would unwind and turn the engine.
Get a load of this fabulous 1968 Toro Whirlwind thusly equipped. What do you guess this mower cost when it was new, in today’s money?
One seldom sees a windup starter in any condition any more. Me, I have two different new old stock Tecumseh units, one round and one square, but that doesn’t count; my tastes are so far off the bell curve it’s a long-distance call from here. Someday someone as
crazed eccentric as I am will come along and free up some garage space by taking them home off me. Here’s Briggs & Stratton’s first design:
The knob on the side extended a spur between adjacent flywheel fan fins when turned to the CRANK position, thus immobilising the engine and allowing spring tension to build. Turning the knob to START withdrew the spur, permitting the flywheel to spin. Trouble was, the knob could be turned (or, with some wear, could float on its own) into CRANK with the engine running, which would damage the flywheel fins and/or decapitate the spur. The later design replaced the flywheel spur with a lever-operated pawl that blocked the starter drive itself until the lever would be flipped into START. Much better. Other than that early goofup, Briggs’ was by far the safest of a very unsafe lot.
The trouble was that once wound up, such a starter was well and truly armed and dangerous. An adult could walk away from a wound-up mower, a child could then touch or jar it, setting off the spring and starting the mower, whereupon hilarious shenanigans were not likely to be what ensued. Or consider the homeowner or mechanic facing a machine with a wound-up impulse starter and a jammed engine or blade: the spring inside, even when not wound up, was strong enough to break bones or worse should it escape its keeper. There was even a Clinton (not the American politician, but the Iowa-based engine company) windup starter for severe-duty applications, with two springs, one atop the other, and a giant bruiser of a drive cup:
There were detailed and warning-laden instructions in the service manuals for neutralising the spring before discard by torching it (at arm’s length) to red-hot at several locations around its circumference within its keeper, but that didn’t address the problem of the armed and jammed mower. Only Briggs & Stratton had the foresight to provide a means of putting the pin back in the grenade, and it was clever, elegant, simple, and cheap: by holding the crank handle with one hand and removing its central screw with the other, the inner end of the spring (which anchored on the central screw) was let go so the wound-up tension was harmlessly if loudly released. And this starter, like Briggs’ coaxial rewind rope starters, used that company’s thoroughly ingenious crankshaft-mounted centrifugally-disengaged sprag clutch—a highly elegant piece of engineering (the patent for which eludes my search efforts; anyone?).
All in all, the windup starter was a keen idea, but it just made the engine starting effort different, not less; recalcitrant mowers still reduced owners to sweating and swearing. The windups were just too dangerous; even before there was any strong consumer product safety commission to insist, these went away by the early ’70s. Anyhow, better ignitions, compression-relief systems, and miniature automotive-type electric starters were making mowers easier to motivate:
Better carburetors, too, but sometimes not. This auction (archived years ago; big pics no longer load, so you’ll have to squint at the thumbnails) was for a Tecumseh gas tank, air filter, and don’t-call-it-a-carburetor setup. It was factory equipment for a couple of years in the mid-late ’60s on Sears Craftsman mowers—do see the 1966 Popular Science writeup—so the design priorities would’ve been (1) cheap, (2) cheap, and (3) cheap. Even so, the nearly featureless 20″ push mower in the article had a 1966 price of $85, or as we say nowadays, $635 (y’think that’s a gobstopper? The aforementioned fabulous Toro was about $820 worth of mower in today’s dollars!).
Engines with this
carburetor had no speed governor per se; no air vane, no flyweight assembly, no linkage. The system, in theory, used airflow through the venturi/intake pipe to limit engine speed to 3800 rpm, which wasn’t a concern in the ’60s but is considered dangerously fast today when most rotary mowers run at whatever speed will give a blade tip velocity of not more than 19,000 ft/min, or 216 mph—generally around 2800 rpm. I say this carburetor used airflow-based speed management “in theory” because I’ve never found anyone who remembers these mowers fondly. They seem uniformly panned as hard starters and poor runners. Note the very shallow fuel tank, which was to minimise the tendency of primitive carburetors like this to provide a richer or leaner mixture depending on how high they had to lift the fuel out of the tank, which in turn depends on the tank’s state of fill. Briggs & Stratton made very extensive use of this kind of simple suction carburetor (apparently known as “self-lift” carburetors in the patent world). The Briggs item was marketed as “Vacu-Jet”, and was somewhat less minimal—it was controlled by an air vane speed governor and worked passably well. Don’t forget, set the mixture with the gas tank half full so it won’t be too rich at full or too lean at empty.
Let’s make it a trifecta: Tecumseh brought out capacitive-discharge electronic ignition in 1978, and Briggs launched their “Magnetron” system in 1982, but Clinton figured out how to get rid of breaker points in 1961: a “Spark Pump” mechanically-actuated piezoelectric ignition system devised by Clevite.
Y’know that red plastic pushbutton on a gas barbecue or fireplace? One push, one “Clack!”, one spark? This is like that, but pressed mechanically once every compression stroke by a lobe on the part of the camshaft that extended above the roof of the crankcase. It was commercialised successfully, but not extensively; Clinton’s market share never approached that of Tecumseh or Briggs (who apparently also invented a piezoelectric ignition system, but never marketed it).
Now, I had a real thing for lawnmowers—particularly their engines—when I was a kid, and I am not the only CCer like that. I couldn’t have a car or a motorcycle, but a lawnmower had an engine and wheels, and that’s a pretty good start when you’re eleven! I pestered the makers for brochures, then cut out the pictures of engines and pasted them on my bedroom walls (I wish I’d kept them intact in a binder, which I suppose is like normal people wishing they’d treated their baseball cards more carefully when they were normal kids).
My early lit included Paul Dempsey’s TAB Books on the topic, and a mid-’70s fixit book with a funky green-and-white cover, written by…Castellano, was it? Yep, this one; what do we see powering the mower on the cover? It’s a Tecumseh LAV-series engine with a windup starter. If you’re particularly sharp of eye, you’ll notice the photo has been printed wrong way round (or maybe this what we’re looking at is the model for Australia and the rest of the Southern hemisphere). And of course the factory service manuals. Oh gawd yes. I bought one or two of them, but wheedled many of them out of the engine manufacturers themselves for the cost of a couple of postage stamps and a handwritten letter; that works surprisingly well when you’re a kid, or at least it did back then. I saved up—$22, I think—and bought a giant early-and-late-production Tecumseh master parts catalogue, about a foot thick, which I spent hours poring over. I used its section dividers as inspiration in response to my science teacher giving me an “N” (“Needs Improvement”, roughly the equivalent of a “D”) for my notebook organisation; the revamped notebook raised my mark to an “E” (“Excellent”, which translates to “A”).
I had a big two-volume complete Clinton parts and service manual, too, which I sorely wish I hadn’t discarded; it was full of fantastic illustrations and some of the most thoughtful explanations of basic engine theory I’ve ever seen. Oh, and there was this completely bizarre book I found at the Denver Public Library, written by one “Barnacle Parp”. That nom de plume and the rambling stream of consciousness that forms the book’s text suggest heavy drugs were flushing around in the outdoor power equipment literary circles of that time.
I had no interest in sputtering, stinking 2-stroke engines by any maker except for a passing curiosity with Outboard Marine Corp’s reputably durable Lawn Boy items. Still don’t. As for real (4-stroke) units, I devoutly, chauvinistically favoured Tecumseh (née Lauson) engines. Beancounters had been loosed by the time I came round, the annual model change fanfare had died way down, innovation in areas other than cost reduction had almost flatlined as mowers and engines got good enough for most purposes and American industry got smug, and Briggs’ engineering was too cost-centric for my taste. Mower engines are a safe place to have strong opinions because the stakes are so low—it’s easy, watch this: vertical-pull starters as a class are dumb, but the Briggs unit is dumbest of all because of all the friction it places on the rope and the slow speed at which it cranks the engine. Yes, it works, but it’s an offensively clumsy piece of thoughtlessly-designed junk compared to the elegance of their sprag clutch arrangement used with horizontal-pull and windup starters. Tecumseh’s vertical-pull starters, except for their early very first design, were differently but equally lousy, though some of them tried to stave off mowing drudgery by dint of entertainingly-labelled handles:
And I preferred Tecumseh’s primer-equipped float carbs, positive-displacement oil pumps, and mechanical governers versus Briggs’ cheaper, more primitive air vanes and oil splash dipper-flingers. Oh, and those flood-o-matic “Pulsa-Jet” carburetors—especially the plastic ones, believe it or don’t—Briggs perched atop the inconveniently-low gas tank.
What I actually had was an eye for industrial design, and a keen interest in it, though I wouldn’t have been able to describe it that way at the time for want of vocabulary. Inspired by the bummed brochures, I made drawings in pencil on newsprint paper of engine designs along Tecumseh’s philosophy, with carefully-rulered lines pointing to various features and blurbs about each one. Not
all many of them had engineering validity, but—eh!—I was 11; whaddya want outta me?
I always thought it’d be fun to put together a cool vintage Toro Whirlwind with a hot rodded Tecumseh engine—it’d’ve probably been their last piece of thoughtful engineering, the OVRM overhead-valve iteration of their LAV/TVS vertical-shaft family, dressed up in period style with oil bath air cleaner, one of their rough-service diaphragm carbs (always wanted to play with one, never got the chance), the fuel cap with the built-in gauge, that giant round funnel-shaped oil minder, a windup starter (natch), a cover plate for the hole in the deck for the dumb down-discharge exhaust Toro used for way too many years—that’s the wrong way to do it unless the goal is to forcefully envelop the operator in a cloud of bladefan-propelled exhaust, not forgetting the gasoline of that time was leaded—and an above-deck SuperQuiet muffler from Tecumseh’s Taylor Muffler division. Red deck, white engine and shroud, lotsa decals. Never had all the right parts at the same time. Got that muffler on the shelf, though; perhaps it’ll go with those two NOS windup starters.
But I’m not in voluminous company, as it seems; a lot of people had no love for the Tecumseh engines. My success with them was almost complete, though. The first was on my father’s ~’79 Craftsman 20″ push rotary. No more groovy metallic blue-green magnesium deck; this one had a red stamped steel deck assembly probably made by Roper. It was powered by a white TVS-90 (stamped with Sears’ 143.xxxxxxx number rather than “TVS-90”, for the sole apparent purpose of adding a step to parts lookup). Fixed throttle position, primer-equipped chokeless carb making the proud AUTOMATIC CHOKE decal on the starter housing a laff (maybe that was another fib by the “Foldamatic handle” guy?), replaceable cylindrical paper air cleaner, electronic ignition, toggle-type spark plug shorting engine stop control—a “secondary”, heh, reason not to wear open-toed shoes while mowing. That mower was the victim of a dishonest mechanic named Craig, probably dead now, who machined the crankshaft almost all the way through just above the blade attachment point and told my dad it was a real good thing he’d brought in the mower (for a tune-up), because the blade could fly off and burst through the deck. This, with the assent of Consumer Reports, was replaced by a Lawn Chief № 51D 20″ push rotary, about $170 ($350 today) from True Value hardware. I’d militated for a Tecumseh engine, and this mower had another TVS-90. Kleen-Aire air filter system this time—a really good piece of engineering—and the engine brake safety quick-stop setup with deadman control on the handle (a concept most of two decades old when it was mandated for 1982).
The Lawn Chief was a basic, inexpensive generic mower. There would’ve been nothing the matter with it if not for my overly-eager tinkering. Thing was, I had that giant parts manual and it was just full of temptingly swappable upgrades: 2-quart fuel tank rather than 1! In white rather than black so as to see the level while filling! Bigger/quieter muffler! With nickel-plated finish! The list went on and on, but I had no money for parts, so I had to hasten the demise of stock parts so as to necessitate their replacement. Scheming little rotter! I am sure dad knew—he had to—that plier crush marks don’t just appear on perfectly good polyethylene fuel tank outlets. He questioned me about it; shoulda busted me for it, but he didn’t. I wish I felt better because my monkeyshines didn’t actually cost a whole lot, but I don’t.
The schmuck who’d demised the Craftsman had tried to sell dad a new Snapper; I was all for it, but dad wasn’t into spending big bucks, hence the Lawn Chief. I kept agitating (and, erm, sabotaging) for a fancier mower, and eventually found a used ’84 Snapper № 214X1PS with a Tecumseh TVXL105 heavy-duty 4hp engine. Self propelled by that company’s intriguing disc-drive setup—earlier versions of which had a Reverse position that was conceptually the same as the other drive speeds except completely dangerous—electric start, commercial-duty model (metal ball-bearing wheels, other upgraded stuff), rear bag + side chute, the works with extra mayo, fries and a large drink. Quite an upgrade, but it definitely hadn’t had my kind of fastidious attention from new; it had chronic carburetor troubles and lost at least one ignition module. I should have just put on a new carb. Or maybe a new engine; some fastneners stripped in the aluminum block, which made it hard to secure the shroud. Only troublesome Tecumseh I had. That model was the heavy-duty version of the one on the cover of the brochure:
The Snapper was eventually replaced by a new Toro, a 1990 model. 21″ rear bag/side chute/mulch kit, self-prop, blade clutch. That year there were engine options: Toro’s new GTS (“Guaranteed To Start”) 2- or 4-stroke engines made by Suzuki, or the Tecumseh OVRM-40 (OHV version of TVS-90, with a nifty lost-foam cylinder head casting). I was rabidly, ignorantly, brassily anti-Japanese at the time; Bob, the owner and chief mechanic of the shop I frequented on thoroughly disreputable East Colfax Avenue in Denver, said the Suzuki was the better engine, but “I know this kid, and if he’s keeping it running, let him pick the engine!” So we got the Tecumseh. There was some difficulty sealing the 2-piece exhaust system, and I think I put one carb kit in it, and half of that was just ’cause I wanted the sexy new red primer bulb rather than the boring basic black one. (Why, no, matter of fact, I didn’t have many friends as a kid…what makes you ask?)
Early on, a sooty smudge on the mower deck near the muffler outlet told me it was running rich. The carb had no mixture needle, though. I wrote one of my letters to the poor guy at Tecumseh—Ken Yoho was his name, and I’m sure he was sick to damn death of my annoying questions and requests for decals. But he sent me the part number for the “high altitude” adjustable main jet/bowl nut, which I installed. Presto, no more soot. The mower itself was rather good. The transmission needed one rebuild, which was not too thrilling, but that’s it. I played around with different blade designs, mulching auxiliary blades, etc., aided and abetted by Bob.
When it came time to clean out the house after dad died and mother was moving to DC, I put the grass catcher through the washing machine a couple times, cleaned and carwaxed the deck and engine, and took it back to the shop. Bob was busy in the back, so one of his employees said “Hey, Bob, this guy says you know him and wants to consign his Toro.” Bob glanced up from his work out back and said “Oh, him? I’m sure it’s in perfect condition; write it up.” A few days later, he called me in; he’d got $350 for it when a guy came in, leaned on it, and asked if he had any good used mowers in stock. When Bob said “That one you’re leaning on”, the guy couldn’t believe it was used and bought it straightaway (original purchase price a decade previous: $450 or so—refer again to those adjusted prices from back in the good ol’ days!). When I went to pick up the check, I gave Bob my giant Tecumseh parts manual; I’d moved on from engines with one cylinder to engines with six of them in a row at a 30-degree incline, and didn’t have space to keep or move the book.
I don’t have a mower any more, because I don’t have a lawn any more. What used to be lawn at my house is now bark mulch and native plants. Everyone’s happier this way: me, the bees, the birds, and the bankbook. But last Autumn when I happened to be in Denver for the first time in many years, I ducked in at the mower shop, still in business, and asked ol’ Bob—much the worse for wear, now—if that parts manual might still be around. It was eventually found under a thick layer of dust and precipitated cigarette smoke, probably untouched since shortly after I’d dropped it off. I hauled it back with me. The exploded views are still fascinating, as are my ancient annotations. And this still makes my teeth itch.
P.S.: On the other side of those big bushes my dad’s mowing near in the lead pic of this article was the driveway, where resided—read all about it in a forthcoming COAL—another of my very early inspirations: