DIY

Refurbishing Used Power Gardening Equipment

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Unlike rotary mowers, few serious gardening machines have been criminally neglected or worked to death. Few single-function gardening machines get more than a few hours of use per season.
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First check of used-engine condition: Remove and inspect air filter. Moderate discoloration is OK, more means careless use.
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Close-fit tools may be needed. Here, a hex-socket with a large Phillips-head bit forms an offset wrench for flushing bolts holding a muffler. Lock jaw pliers are needed for other bolts.
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We rescued our thirty-year-old Gravely from an immoderate late-winter snowfall, and fired it to life with just a new spark plug and a shot of starter fluid.
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Measure the attachment circle on the back of an engine from center to center of opposing bolt holes and across center of circle. Order a replacement engine of same size and configuration (here, a new 7 hp horizontal shaft Tecumseh "tiller" engine with a 3 5/8 inch 4-bolt circle).
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First step in revitalizing a used engine is squirting carburetor, inside and out, with carb cleaner. Remove mixture-adjust screws and squirt them, too (see the following photo to identify screws).
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Spark plug is removed with a rubber-core sparkplug socket (not pliers or common sockets, or you can snap the ceramic insulator). A gapping tool is needed to set the gap: .025 on J-8s and 0.35 on J-10s, the most common outdoor-tool plugs.
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Here, carburetor is off. Linkage wire are unhooked and twist ties are used to flag holes for correct reassembly. Screwdriver points to upper-mixture adjust screws. Lower adjust screw is at bottom.
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For ease in repair and storage, install an aftermarket cut-off in fuel-line between gas tank and carb. Fasten to hose with stainless screw-type clamps. Improve engine longevity by installing a fuel filter in the other (tank) end of fuel line as well.

Tips on evaluating, buying, and refurbishing used power gardening equipment. (See the image gallery for garden equipment photos.)

You say you don’t fancy the idea of spending as much for a
new gardening machine as you’d pay for a barn roof or a
good used truck? Well, scout around for a good used garden
tractor, tiller, or shredder. Your selection may be limited
to older models, but you’ll save at least half the new
price and may get a real bargain. Even rebuilding the
engine in an older model will work out to be significantly
less expensive than buying new. Learn about refurbishing used power gardening equipment. Here’s how to find an older
gem and make it shine again.

Unlike rotary mowers, few serious gardening machines have
been criminally neglected or worked to death. Few
single-function gardening machines get more than a few
hours of use per season. Multiple-use models such as garden
tractor/tillers with snowblower, shredder, and mower
attachments can work happily year-round. But hardly any in
non-commercial use will see service more than three or four
times per month–and they are made with big
truck-tough running gear and industrial/commercial engines
designed to go 5,000 hours before needing a rebuild. Small
wonder that 50-year-old lawn tractors are still working
faithfully (for owners who maintain them conscientiously).

And don’t evaluate the cost of a used power gardening
machine by comparing it with alternative uses for the
cash–or even for a loan. Price out the hours and
hours and hours of sweat-labor it will spare you (and maybe
your heirs) every year for the next half-century.

MOTHER’s Choice

Last fall (the best season to get a good price on gardening
equipment), MOTHER went looking for a machine to establish
and maintain our new country gardens. We settled on a
’60s-era Gravely “L” with 12 volt battery electric start, a
big rotary mower/brush-hog, a sickle bar, riding sulky,
dozer-blade for snow or gravel, and extra wheels with snow
chains. Prices for similar packages ranged from $1,500 to
our cost, $350. A like-new rotary plow costs another $150
(we could have dickered it down some), and we are still
looking for a tiller and cultivator frame and spades.

Beauty Is Tin Deep

First impressions of used garden gear can be misleading. A
gardener often fails to realize that Old Faithful isn’t
needed any longer till it’s been sitting idle for months or
years. So many perfectly good old tillers, tractors, and
shredders have an accumulation of dried mud, dings,
cobwebs, and surface rust that may signify little.

Your best indication of usage is tire-condition. New tires
on an old machine are rare. The cleats molded into the
rubber tires of tractors and tillers wear slowly on soil
and sod. If you see low and thin, badly-worn cleats with
rounded edges, cracks, and nicks you know the machine has
worked on pavement or has really been around. Most tires
are worn but still serviceable after 20 years or more.

Don’t worry much about paint condition or surface rust on
tractors and tillers. Bright original paint means the
machine has been stored inside and seldom left out in sun
and rain — indication of excellent past treatment and
little use. Desirable, but not essential. How much
full-scale farm equipment have you seen just left in the
fields (with sensitive parts well-greased) ready for uses
year after year? It is tough stuff.

Faded paint indicates outside storage, as sun bleaches.
Repaintings suggest multiple owners (typical of older
machines such as MOTHER’S new/old Gravely that has
circulated locally among several owners . . . for the same
sales price . . . for decades). Our machine is painted green
over the original orange by someone who just liked the
color. So do we.

Rusted tractor shrouds, tiller-tine hoods, gas tanks, and
most other sheet metal parts can be ignored or replaced
easily and cheaply.

But surface rust does count on shredder-grinders made with
a steel framework. The bearings that hold the whirling
chopper reels are bolted or welded to the sides of the
frame, which are exposed to acidic plant material that
encourages rust nearly as much as road salt corrodes
automobile tin.

Shake the reel hard and be sure it does not move up and
down within the bearings. You can replace bearings, but
must also replace the main shaft …which means you need to
gut the machine and replace all the moving parts. Might as
well buy a new shredder.

The fasteners that hold the bearings in, and/or the metal
around the punch out made for the bearing casing, and/or
bolts can corrode. The flail reel vibrates in use and will
quickly rattle loose in a corroded sheet-metal frame even
if the bearings remain solid. (This is why we are partial
to the old WW II line, with its drop-dead sturdy cast-iron
side-frames.) So, inspect an old shredder carefully for
rust around bearings, bolts that hold the frame together,
and around safety shields and baffles. Lightly rusted nuts
and bolt heads can be gussied up with a wire brush and
paint. But look for rot in the sheet metal they poke
through. Reject any machine with noticeable frame
corrosion.

Try to make any self-propelled machine wobble on its
wheels. If it does cant to one side, you may have bad wheel
bearings. Shake tiller assemblies, PTO shafts, and pulley
journals. All should set solidly in their bearings. Pulleys
that wobble or are loose on the shaft may be replaceable,
as the soft metal of the pulley hub wears before the shaft.
But if an axle or drive shaft is at all loose, you may be
asking for major repairs.

Garden Equipment Engines

Except for older machines with a proprietary engine (’20s
models, Gravely through the Model “L,” rare Franklin
tractors and others that belong in a museum rather than in
your corn patch), engines are purchased from Briggs,
Tecumseh, or another engine maker. The gardening machine
and its engine are made and warranted by separate
manufacturers. And though the engine appears to be the
heart of the equipment, it isn’t. Engines are expendable
and interchangeable.

It’s instructive to examine the prepaid maintenance
agreements and “extended warranties” offered for garden
machines by major retailers. Sears’ 1996 agreement for its
shredder grinder lists only four engine repairs: tune up
($15), replace muffler ($19), replace carburetor ($60)
— each with an hour of labor. The fourth is to
replace the entire engine at a cost of $350 plus an hour
and a half of labor. This is typical of today’s labor
market and increasingly modular manufacturing protocols.
Few franchised small-engine shops bother to repair a carb;
indeed, many are “throw-away” designs that are crimped or
riveted (not screwed) together, so they can’t be
disassembled for repair. And, if anything goes wrong inside
the engine, labor and new parts cost more than a new
engine, so the bad one is simply replaced.

Every town has a few small-engine mechanics who have the
tools, know-how, and time to go into engines, and many are
very good at it. But unless you know such an old pro
personally, you are best advised to follow the times. If an
under 10 hp engine is bad, plan on replacing it. The cost
ranges from $150 and up, and you can do it yourself (see
below). If you know a good small-engine rebuilder, you can
save money by rebuilding the larger power plants. Cost is
usually about half the price of a new engine.

To check an engine, ignore a rusted-out muffler and surface
grease or dirt. Mufflers rust more in disuse than hard
service and they are easily and cheaply replaced (soak with
penetrating oil, use hammer and chisel to loosen keeper
ring, and unscrew with a monkey wrench.)

First, remove air cleaner housing cover and inspect the
cleaner element. If it is pristine, the owner is
conscientious at maintenance or is trying to impress you. A
light coating of dust on the element and outer surface of
the housing is normal. If element is thick with dust or
housing is packed with dust, grass, and dead moths, the
machine has not been well-treated–no matter how
glossy the outside. Remove the element slowly and
carefully; the entire inside of the housing and carb behind
the inner element gasket should be shiny clean. If it is
even a bit dusty, dirt is getting into the engine and,
acting like sandpaper, is wearing down the moving parts.

Pull dipstick and inspect oil on it. Fresh-changed oil can
be a warning sign: Is the owner conscientious or trying to
mask problems? Dark but still clear oil is
preferable-suggesting that the machine has been used, but
not abused. Dark and murky is less good. Black, murky, and
gritty means poor maintenance. If oil smells burned, the
bearings may be going. If no oil shows on the dipstick, the
engine is leaking or using oil. Whatever, the owner is
negligent for not keeping it topped up and the engine may
shortly be toast.

Using proper tools, remove the spark plug (best to ask
owners to remove it; if they don’t know how, be doubly
alert to problems). The little hook on the end (the
electrode) should look clean and dry — a sort of
gray. If it is thinner on the end than the base, it needs
changing; and any performance problems may be due to an old
plug. If the plug end is black and greasy, the oil is
blowing by piston or valves — a bad sign.

The most reliable way I know to evaluate the insides of an
engine (short of tearing it apart) is to start it and get
it warmed up, then look and listen carefully. A loud knock
that may be accompanied by a small shudder (as opposed to a
click or a tick) indicates a major problem (rod/crank
bearing or main bearings going or gone.) Even-spaced,
gentle tick-tick-ticks are normal. Listen for uneven
clicks, especially if, when you slow engine speed, the
engine makes blue smoke or twitches in time with the
off-beat click. This can be a bad valve.

Use the throttle to accelerate and decelerate fairly
sharply. If the engine sputters and coughs without making
blue smoke it has a carburetion problem. Black smoke is
unburned fuel (unless you sense a bad valve) — also a
carburetion problem.

Don’t worry if an engine–especially one of the large,
old single-cylinder models — smokes briefly on
start-up. A puff of black smoke on changing speeds is
usually a fouled spark plug or too-rich carb setting. But
if it puffs blue smoke on change of speed, the rings are
worn, which means the piston and cylinder are also
scratched. Using a thick engine oil may give the engine
added life, but the problem will never cure itself and
eventually the engine will fail.

Garden Equipment Fix-Up

Many apparent carburetion problems can be cured by
installing a new spark plug. Remove the old plug with a
proper spark plug socket on your ratchet handle. Take the
old plug to the parts store and have them gap a replacement
plug for you. (The most common small-engine plugs, J-8s and
J-10s, use a .025 gap — the space between electrodes
where the spark that fires the fuel is generated. Gap it
yourself if you have a feeler gauge or plug-gapping tool.)
Put a small coating of oil on the plug threads.

Replace plug, running it well into the head with your
fingers…being sure it is threaded in properly. Don’t
force it …keep trying to restart it ’til it threads in
with minimal force. Tighten just snug (not real tight) with
wrench. Replace plug, put a nail in the plug end of the
ignition, hold nail close to top of plug with
plastic-handled pliers. Pull starter rope or engage
electric starter. A thick blue spark should jump from nail
to plug. If there’s no spark or a weak one you have a
magneto problem–most probably a bad condenser . . . but
getting at it requires removing the flywheel or
disassembling the magneto. Job for a pro (or at least aid
of a repair manual).

First, though, replace the plug wire (new part from a
small-engine shop) if you can get it free without major
surgery. Corrosion or water entering through old, cracked
plug wires causes more ignition problems than anything but
fouled plugs. Use sandpaper to brighten up connectors and a
blob of dielectric grease on each terminal to waterproof
them.

Most carburetion problems can be fixed by fiddling with the
idle and hi-speed mixture screws on the carburetor. Idle is
the big one low on the engine or under the float bowl;
hi-speed is the little one at the throat of the carb. Set
each so engine runs fastest, but without sounding starved,
at idle and at hi-speed. Idle can be adjusted with a third
screw on the throttle control; set it low, but high enough
that exhaust stays clean (no black smoke when you
accelerate).

If that doesn’t work, clean the carb. Use an open space and
be sure there is no fire anywhere near. Drain or shut off
fuel. Remove and clean the glass sediment bowl on larger
carbs. Remove both needle-valve/adjusting screws (counting
full turns and partial turns–down to the
quarter-turn) as you back them out. Watch for (and do not
lose) the tiny “O” rings, washers, and springs that come
off with the adjustment screws

When removing the idle adjust at the bottom of a metal
bowl, fuel will flow out, which is good; it’s likely full
of water and crud. Catch it in a pot and dispose of
properly.

Using the little straw that comes with it, blow carburetor
cleaner up into both screw holes. Put a pot under carb to
catch dribbling cleaner and any small parts that blow out
(and watch to see where they come from). Where you see it
bubble out down inside the carb, blow some cleaner back out
Clean carb throat. With pressure air (a non-freon aerosol
“can of air” is cheaper than an air compressor), blow carb
out. Replace screws the number of turns they were
originally, hook up fuel, being sure there are no leaks,
fire her up and fiddle with the screws a quarter turn at a
time ’til the engine starts and runs well at idle and
hi-speed.

If this doesn’t work, remove carb and attachments
(reserving all the stamped-metal throttle and choke
controls attached to the engine). Take the carb to a shop
along with serial numbers off the engine and see if they
have a quick fix. If not, order a new one. Be sure the new
one is adjusted properly when you pick it up. Carburetors
run from $5 to $50.

Garden Equipment Lube

A machine that’s been sitting for a while will need a
thorough greasing. Control levers must work easily and
wires must slip freely inside their sheaths.

If controls stick, soak with penetrating oil and work loose
if you can. Often it’s easier just to replace the controls.
Generic handles and wire-and-sheath assemblies are
available off the rack at auto supply stores. One or the
other is sure to replace your old throttle, choke, and
light accessory controls.

Hot water and a degreasing detergent, a good solvent,
toothbrush, emery-paper, and elbow grease will clean up
most any machine. When all is de-gooked, de-gummed, and
shiny, blow water out of axles and engine parts and coat
all surfaces with light oil — or, prime and paint.

A certified antique may have shaft, pulley, or wheel
bearings with auto-type Alemite “Zerk” fittings that must
be greased. Look for little steel nubbins with a tiny ball
bearing in the center — located around shafts and
other major moving parts. If you find them, get a
cartridge-type grease gun and give the fittings a shot of
grease every week of heavy use. (Wipe fitting clean, push
nozzle tip on fitting ’til it pops tight and squeeze ’til
old grease oozes out.) Most newer equipment has sealed
bearings that don’t need maintenance.

Machines with automotive-type transmissions and wheel/PTO
drives that run in oil need only to have the lube topped up
and changed any time it gets murky or you see the white,
waxy indication of water on the dip stick.

If balloon tires are shot, remove wheels and take to any
L&G shop, which will install new tires for you. You may
want to take the wheels home, sand, and paint them (with
special attention to the edges of the rim) before new tires
go on. Solid tires are bonded or sprung onto rims and the
whole thing must be replaced if rubber is badly cracked.

With engine and wheels off, remove shields covering drive
gear. You should be able to replace any worn belts, worn or
loose pulleys, and idler arms, as the hardware and parts
are available at auto parts stores. Floppy or broken drive
chains that can’t be replaced and tightened with
intuitively-apparent adjustment screws and any work on gear
drives should be taken to a shop. It requires specialized
tools and know-how that you surely can acquire–but
the tools cost isn’t justified. And the study required
would take time that’s better spent gardening.

Replacing Tines

Tiller tines wear and lose efficiency faster then you might
think. But the loss of mass, length, and sharpness is so
gradual that few owners notice.

Check yours every now and again. If the end few inches of a
tine are noticeably thinner than where it fastens to the
reel, order a new set. Bolt-spacing is fairly standard and
a set of replacement tines from Sears will fit nearly any
generic front-ender. Many larger-hp, name-brand
front-enders and most rear-tined machines use custom tines.
Order from dealer or the parts/repair phones of
mail-order-sold machines. Cost for a set of 16 replacement
tines ranges from $20 for simple stampings used on small-hp
front-enders to around $75 for forged, complex-curved
“bolos.”

Tines are either right- or left-handed, and they are
arrayed around the tine-reels in a complex, interwoven
pattern of right/left opposition that is easy to get
confused, so its easiest to remove and replace one tine at
a time. Confuse the pattern and you’ll never get it right
again without consulting another machine.

On a used tiller (or just to maintain your own) you may
want to disassemble the whole lower unit to replace a drive
chain or to de-rust and repaint. Most tillers have four
tine-reel assemblies. Some are welded in one piece and must
be replaced entirely. On others, tine-stubs are welded to a
short section of tubing and the tines are bolted to stubs.

Tine-axle-tubing is held to axle shaft with a shear pin,
big cotter key, or a soft-steel bolt (all designed to shear
if subjected to excess stress). File deep scratches all
across tops of all the axle-tubes before removing them.
Scratch a notch on the axle drive shaft where the scratches
line up and scratch- number the assemblies right to left.
Then, file left or right arrows on the tine stubs, and you
can tear it all apart to clean it up good and get paint
into all the hidden crannies. Just don’t quit the job and
store the loose parts in a box for six months, or you are
sure to forget what your scratch-code means… if the
scratches don’t rust into oblivion.

Tines should come off with a pair of wrenches, tine
assemblies with a few whacks of a hammer. If frozen on,
soak with water to remove caked-on mud and with penetrating
oil (using a torch if need be ) to loosen rust. If that
doesn’t do it, heat with a propane torch and work at it
with screwdrivers and a mallet. Then, wire-brush flat
pieces to bare metal and soak tube insides and inaccessible
surfaces with Naval Jelly or other rust-remover. Rinse with
hose, dry and dust good, spray-paint with a good metal
undercoat such as Rustoleum, and repaint within 24 hours
with two coats of hard gloss enamel. Grease axles and
hidden surfaces where tines bolt on, and fasten securely
with new galvanized or stainless steel (rustproof)
hardware. Apply the same procedure to exposed tin, handles,
and engine shrouds. Let paint harden for a week before
using the machine and you are good fog many more seasons of
power gardening

You are best advised to replace the relatively small blades
on conventional rotary mower attachments; even two- and
three-bladed models use standard blades But the thick
blades from multiple-blade commercial mowers and
“Brush-Hog” mowers are too expensive to discard. You’ll
need a monkey wrench or a wrench and blade-holder to get
the blades off. Be sure to save any washers or blade-insert
that come off and remember where they go. Blade ends may be
badly dented. If so, even out with hammer and anvil or a
grinder. Then balance on a conical blade balancer (from any
small-engine parts rack) by grinding off the heavy side;
sharpen well and reattach.

Replacing an Engine

If the engine is shot, replacing it is easier than you may
think. Remove fuel lines and drain gas. Remove gas tank and
the whole carburetor-control assembly from engine. Remove
any reverse-controls and PTO links (to engines with a
second PTO shaft). Take off everything that’s bolted to the
engine but the shroud where the starting rope is attached,
the carburetor, and muffler.

Then, remove the engine. It fastens to the machine with
four bolts arranged in a circle at its back, or with four
bolts in a square on the base. Measure bolt pattern, and
locate and record model numbers that are stamped into one
side or top of the shroud on smaller engines, into a flat
space on the cast-metal crankcase on larger sizes.

Pull at pulleys or gears attached to shaft If they don’t
come off with a few hammer taps, take it to a shop with
gear pulleys and skilled staff, have them install gears on
the new engine as well. Then, buy an engine of the same or
one step greater horsepower with precisely the same bolt
pattern and shaft or shafts of the same diameter, length,
and spline slot (where a little half-moon shaped soft-metal
shear pin goes to secure engine shaft to pulley or drive
shaft of the machine itself.)

Good used engines can be had from want ads and some engine
shops for $50, to $100. Many auto supply outlets sell new
ones. Best new engine prices I know of are available from
the catalog (free) from Northern. Their
sales staff will give you all the help you need to obtain the closest replacement possible.

A 2,500-hr 7 hp Tecumseh standard tiller engine costs about
$150 on sale, just under $200 otherwise. An 8 hp Briggs
& Stratton Industrial/Commercial for a big shredder or
tiller costs $375. A 10 hp Kohler with electric start for a
tiller/tractor costs $690. An 18 hp Onan or Honda twin (to
replace a shot engine on a Gravely “L”) costs $1,100. All
mfgrs. offer standard, I/C, electric start and other
premium options.

You don’t have to get a carbon copy of your old engine.
Indeed, the original brand and/or model may not be
available any more. Only shaft-sizes and engine-mount-holes
must match on original and replacement.

Do your best to get an engine that eliminates known
problems with the original. For example, many tillers come
equipped with engines with a carburetor that sticks out to
one side of the engine and can be broken off easily against
shed-door jams and fence posts. Among the replacements
available are several with less-hazardous designs. I once
replaced a conventional 7 hp tiller engine with a 5 hp
“Robin” that had the carb mounted safely at the rear of the
engine. Like most replacements, it came with a
self-contained throttle assembly, so I didn’t bother to
reattach the handle-mounted throttle control but took it
off entirely and regulated engine speed at the engine.
Today, the 5 hp Robin costs $290–a third more
expensive but with 50 percent more service life than
standard engines.

I removed the pancake-style gas tank, wired the original
(oblong-box) gas tank onto the handle cross-bar and
connected it to the new carb with a length of armored fuel
line. I put a gas filter in mid- line and a fuel shut-off
on the tank bottom, so I was able to keep the fuel clean
and fuel the tiller while the engine was hot without fear
of an explosion.

Once you’ve replaced an engine yourself (and realize how
simple it is), you’ll find that such custom modifications
just sort of come to you. And with the confidence borne of
performing such a seemingly formidable task, you’ll find
all kinds of auto-type mechanics easy.

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