Howard Gem User manual

Howard"
Rotavator"Gem
"
and Super Gem
Operating + >. Instructions - - .:

GENERAL SAFETY PRECAUTIONS
1. Read and familiarise yourself with the
operating instruction book.
2. Do not allow children to operate the machine.
Do not allow adults to operate the machine
without proper instructions.
3. Clear the work area of objects which might be
picked up and thrown.
4. Before attempting to start -themachineensure
the gear lever
is in neutral and the rotor drive
disengaged.
5. Nevertamperwiththe reverse gear mechanism,
this
is asafety device.
6. Disengage the rotor drive before reversing or
turning the machine.
7. Work up and down the face of steep slopes,
never across them.
8. Handle petrol with care -
Use an approved petrol container.
Never removethecap of the fuel tank or add
petrol toa runningor hot engine, or fill the
tank indoors. Wipe up spilled petrol.
9. Open doors if the engine is run in the garage -
exhaust fumes are dangerous.
1.0. Keep all nuts, bolts and screws tight and be
sure that the equipment is regularly lubricated
to keep
it in a safe working condition.
11. Keep all safety guards in place.
12. Never touch the rotor with the engine
running
- switch off first.
13. Always wear substantial footwear to provide
as much protection
as possible.
14. The warning transfer (part number 27409)
illustrated below should always be in position
onyour machine. If, for any reason
it is missing
a replacementwill be supplied free of charge.
WARNING
beware of rotating
blades see there
is no one in the
direction of driving

Howard
Rotavator
Gem
and Super Gem
Operating Instructions
CONTENTS
Aircleaner ......................... 8
Blade maintenance ...................... 8
Cleaning chaincase ...................... 8
Cleaning gearbox ....................... 8
Drivechain ......................... 8
Roadwheels ........................ 8
Rotor flange weedcutters .................... 8
Rotor friction drive ...................... 8
Attachments ......................... 10
Depth control wheel
..................... 10
Furrower .......................... 10
Pictine rotor ........................ 10
............................ Controis 3
.................... Lubrication and maintenance 5
Lubrication and maintenancechart ................ 6 & 7
Makingthe most of your Gem .................... 11
......................... Rotor and blades 9
Serial number .......................... 2
Specifications .......................... 2
....................... Working the machine 4
........................ Your new machine 3
The Howard Gem is THE heavy duty hand-controlled
Rotavator for growers. farmersand contractors
.
From seedbed making to land reclaiming. catch cropping to
weed control. mixing-in manureto breaking up pasture. the
work power and engineering quality of the Gem are
unequalled
.
The Gem has three forward gears providing the right speed
for any type of work or soil condition
. A reverse gear gives
ease of handling in confined areas; adjustable handlebars.
up or down. side to side. aid operator comfort and
flexibility of control
.
Simple construction and a proven design keep maintenance
to
a minimum .
Optional attachments include a furrower. depth control
wheel and front-end weights
.

SPECIFICATIONS
ENGIIVE LANDSPEEDS
(at 2800 rpm)
STANDARD GEM
Kohler K301T 4-stroke petrol producing 11 hp
(rnax.) at 2800 rprn governed engine speed. 22 Ib-ft
(30 Nm)torque at 2200 rprn or
Hatz E780 4-stroke diesel producing 9 hp (max.)
at 3000 rprn governed engine speed. 19 Ib-ft
(25.75 Nm)torque
at 2100 rpm.
SUPER GEM
Kohler K341T 4-stroke petrol producing 15 hp
(rnax.)
at 2800 rprn governed engine speed. 28 Ib-
ft 138 Nm)torque at 2600 rprn or
Hatz E785 4-stroke diesel producing 11 hp (rnax.)
at 3000 rprn governed engine speed. 23 Ib-ft
(31Nm)torque at 2100 rpm.
FUEL CAPACITY
9 litres (2gallons).
TRANSMISSIQN
Three forward speeds, one reverse. Transmissionby
hardenedgears runninginoiI.All shafts mounted on
ball-bearings.Fulldifferential for easy turning, with
automatic locking when rotor is engaged. Safety
clutch with slip action when under shock load.
CLUTCH
Heavy duty two-platedry type.
CONTROLS
1. Rod-operated clutch lever with safety reverse
interlock.
2. Engine governor control by Bowden cable.
3. Rod-operatedgear lever.
4. Rod-operatedrotor engagement lever.
5. Handlebars adjustable for height and sideswing.
6. Depth setting lever.
WHEELS
4.00
- 12 2-ply traction tread pneumatic tyres.
Tyre pressure 1.4 kg/cm2 (201b/in2).
ROTOR
Rotor speed 188 rprn
at 2800 rprn engine speed.
Rotor widths 51 cm (20 in) Standard GEM only.
61 cm (24 in) Standard and Super
GEM.
76 cm (30 in) Super
GEM (diesel)
on1 y.
DEPTH OF CUT
Adjustable to 23 cm (9in) maximum.
1
st gear 1.54 km/h (0.96 mile/h).
2nd gear 2.3 km/h (1.46 milelh).
3rd gear 4.9 km/h (3.05 mile/h).
Reverse 2.9 km/h (1.85 mile/h).
OILCAPACITY
Gearbox
- 3.4 litres (6pints)
Chaincase - .25 litre ( ;pint)
Engine - see Engine handbook
DIMENSIONS
Length:203 cm (80in)petrol:208 cm (82 in) diesel:
Height to top of handlebar: 104 cm (41 in).
Width: 63 cm (25 in)
- 51 cm (20 in) rotor.
74
cm (29 in)
- 61 cm
(24
in) rotor.
89
cm
(35
in)
- 76 cm (30 in) rotor.
WEIGHT
(Approx.)
Standard GEM - Kohler engine.
292 kg (644Ib)
- 50cm (20in) rotor.
305 kg (672Ib)
- 61 cm (24in) rotor.
Standard GEM
- Hatz engine.
296 kg (652
Ib) - 50cm (20in) rotor.
306 kg (674 Ib) - 61 cm (24in) rotor.
Super
GEM - Kohler engine.
312 kg (688Ib)
- 61 cm (24in) rotor.
Super GEM
- Hatz engine.
338 kg (746 Ib)
- 61 cm (24in) rotor.
391 kg (862Ib)
- 76 cm (30in) rotor.
EXTRA EQUIPMENT
Depth Control Wheel; Furrower; Pictine Rotor.
Front-endWeights.
RECOMMENDED LUBRlCAlVTS
SAE 90 - Gearbox and chaincase.
EngineOil
- Rotor Dog Clutch; rotor stub axle;
depth control wheel (iffitted).
SERIAL NUMBER
The serial number of the Gem
is stamped on the
plate fixed to the left-hand top side of the front
shield, and on the main frame top side near the
handlebar pivot.
For future reference, record the serial number in
the space below:
.................................. Gem Serial No
Date Purchased
.................................

YOUR NEW MACHINE
On receipt of your new "Gem" first read and study the
instruction manuals for both engine and machine.
Satisfactory performanceandalongworking lifefor your
Rotavator will depend upon your following the instruc-
tions given. Be certain to keep the manuals in a safe,
convenient place ready for quick reference.
When in need of spare parts or service, contact your
Howard dealer. He has genuine replacement Howard
parts, and trained, experienced staff to service your
machine correctly.
Before starting to use your "Gem", first fill thefuel tank,
check the gearbox and chaincase oil levels, and the
lubrication points. Check that all nuts and bolts are
tight.
Run the machine lightly at first, and gradually increase
the loads during the first
25 hours work. NEVER allow
the engine to labour during this running-in period.
After the first five hours of operation, check all nuts and
bolts for tightness, including the two wheel hub centre
nuts.
CONTROLS
HANDLEBAR
ROTOR
IGNITION
ENGAGEMENT
LEVER
9a
B THROTTLE
CONTROL
EAR LEVER

WORKING THE MACHINE
Start the engine according to the engine instruction
book. Lift the clutch lever and engage the required gear.
DO NOT FORCE THE GEARS INTO MESH. If they do
not immediately engage, release the clutch lever
momentarily.
The slight noise which may be heard when the clutch
is engaged is due to the positive action of the twin
clutch plates.
When in a position to begin Rotavating, lift the clutch
lever again, and move the rotor engagement lever to
the "IN" position.Increase the engine speed and gently
release the clutch, allowing the machine to pull itself
into the work.
The rotor engagement lever also operates the differ-
ential lock. The lever must therefore be put into the
"OUT" position for turning.
The depth is controlled by pressing the depth control
lever to the right. This releases the skid in the socket,
allowing itto be repositioned as required.The skid itself
has two alternative holes, the lower one of which per-
mits a greater depth to be obtained.
Choose the depth to suit the crop being planted. Itthis
is deeper than can be obtained in one pass without the
engine labouring, several passes should be made at
progressively increasing depths.
First gear should be used for heavy work, and where a
fine tilth is required Second gear should be used for
average conditions, and top gear for light hoeing and
road work.
Where a coarse tilth is required, the rotor shield should
be raised as high as possible with the trailing board
folded back. The rotor should always be disengaged
when reversing as well as when turning at headlands.
To stop the machine, raise the clutch lever, and move
the gear lever to the centre (neutral) position. Move
the rotor engagement lever to the "OUT" position and
then release the clutch.
REVERSING
To reverse, pull upthe clutch lever, move the gear lever
to Reverse (this simultaneously operates the safety
interlock) and release the clutch lever. No movement
occurs until the clutch lever is pushed down. Removal
of pressure automatically stops the machine. To dis-
engage levers, pull up the clutch lever and move the
lever to neutral.
IVEVER, UNDER ANY CIRCUMSTAIVCES, TAMPER
WlTH THE REVERSE GEAR LINKAGE. THE INTER-
LOCK MECHANISMISASAFETYDEVICEAND MUST
NOT BE INTERFERED WlTH OR REMOVED.
TURNING
It is often found that the machine is most easily turned
in reverse gear, especially when ground conditions are
very wet and sticky, w~tha considerable amount of
earth adhering to the underside
of the shield Prov~ded
the rotor is disengaged and the blades are lifted clear of
the ground, the machine can be turned quite eas~ly,
either in forward or reverse gear If turning appearsto be
difficuit, ctieck that the differe~tiallock is fully dis-
engaged when the rotor lever is pulled back. Adjust-
ment can be made on tt-ie differential lock control rod,
should this not be the case.
HANDLEBAR ADJUSTMENT
The height of the handlet~arscan be adjustedto suit the
operator, bymeansofthealternative holes inthe handle-
bar lugs.
The handlebars can also be offset to one side or the
other, by pressing downthe handlebar positioning lever
to its full extent, and swinging the handlebarstowhich-
ever side is required.
A hole is provided at each end of
the handlebar slide for positive locking in the required
position
HINTS FOR TOP PERFORMANCE
1. The importance of correct and regular lubrication
cannot be over-stated. Study the lubrication chart on
pages
6 and 7.
2. Do not neglect air cleaner maintenance.
3. Always shut the throttle to the idling position when
lifting the clutch lever for engaging or disengaging
gears.
4. Do not allow the engine to idle at slow speeds for
long periods.
5. Do not press the handles down should the machine
jump if hitting a stump or similar obstacle; lightly resist
the movement and let the machine right itself. This
applies particularly when working on hillsides in badly
cleared land.
6. When taking sharp corners, put the rotor out of gear,
lifting the handlebars to help in turning.
7. Never run the "Gem" with the engine labouring.
Selection of the right gear, and correct depth of work
ensures a constant reserve of engine power.
8. Always use the clutch in the same way as in a car,
that is, for changing gear only. DO NOT "slip the
clutch" to obtain extra engine speed.
9. For the first 25 hours, attempt only fairly light work,
to allow the working partsto "bed down".

LUBRICATION AND MAINTENANCE
The simple, sturdy construction of the Howard "Gem"
enables it to w~thstandthe toughest conditions of work
and use The small aniount of maintenance and lubrica-
tion detailed below, w~ll,if done regularly, extend its
working life and rnainta~nits high efficiency.
BEFORE OILING, ADJUSTING OR SERVICING
THE MACHINE SWITCH OFF THE ENGINE
OILS
Use only good quality 011s.SAE 90 grade should be
used in the gearbox and chaincase; engine oil for all
other lubricat~onpoints.
AIR CLEANER
The alr cleaner is of the oil-bath type, and its niainten-
ance must not be neglected. Never allow sediment to
build up In the air cleaner base. In dusty conditions,
change the air cleaner oil tw~cea day; if not changed
promptly, the accumulated dust in the oil-bath will
raise ttie level of the oil to a point where dirt-laden oil
will be sucked into the engine, to cause immediate and
costly damage.
FIRST MAINTENANCE
(if niach~rienot already serviced by dealer) :
1.Check engrne oil level.
2. Check ttie alr cleaner oil level.
3. Check tightness of all nuts and bolts.
4. Check the gearbox oil level (with the dipstick
attached to the square-headed plug screwed into the
gearbox top)
5. Check the chaincase oil level: with the bladestouch-
ing the ground, oil shouldjust seep out of the level hole
at the lower rear of the chaincase, with the oil level
plug removed.
6. Check the tension of the drive chain; total up and
downnlovenient should benomorethan
2 in. (9.5mm.)
to 4 in. (1 2.7 rnm.).See Adjustments Section, page 8.
7. Lubricate the rotor stub axle with an oilcan (the oil-
way screw IS located on the rotor tube just inside the
r~ght-handflange).
8. Oil the rotor dogs; remove the small square-headed
plug from the top side of the rotor dog clutch housing
and lubricate with several strokes from an oilcan.
9. Lightly oil the throttle cable, the gear, clutch, and
rotor control pivots, handlebar swivel and slide, shield
hinges and depth control adjustment.
10. Check that the engine clutch is adjustedto give in.
(6 rnm.) free movement at the handlebar lever. Adjust-
ment should be taken upat the front clutch control arm
by means of the wing nut.
11 Check tyre pressures (20 p.s.i.
- 1.4kg./sq.cm.).
12. Check that the weed cutter blades just clear the
outside blades of the rotor.
EVERY 10 HOURS OR DAILY
1. Check the engine oil level.
2. Check the level and condition of the air cleaner oil;
wash out with petrol and replenish with fresh oil if
necessary (twice daily if very dusty conditions).
3. Check tightness of blade bolts, and straighten any
bent blades, using the blade setting bar.
4. Watch for signs of excessive rotor clutch slip. Adjust
if necessary, on the four spring-loaded clutch nuts on
the rotor left-hand end. For normal setting, tighten the
nuts to fully compress the springs, then slacken back
each nut half a turn
EVERY 25 HOURS OR WEEKLY
(additional to 10 Hours maintenance)
1. Service the engine (see engine instruction book).
2. Check gearbox oil level.
3. Check chaincase oil level.
4. Check chain tension.
5. Oil rotor dogs.
6. Oil the rotor stub axle bearing.
7. Oil all pivot points, hinges, and other oiling points
(see First Maintenance, para. 9 above).
8. Check the engine clutch adjc~stnientand reset if
necessary.
9. Remove and clean out the sediment bowl on the
fuel tank.
10. Check all nuts and bolts for tightness.
11. Check tyre pressures.
12. Adjust weed cutter blades if necessary.
EVERY 250 HOURS OR 3 MONTHLY
(additional to 10 Hours and 25 Hours nia~ntenancej
1.Drain the gearbox, flush out and ref111w~th 6 pints
(3.4litres) SAE 90 gear oil (See Adjustments section,
page 8).
2. Remove the chaincase, and wash the chilin and the
case with petrol Replaceand ref111with
;: plr~t(.25litre)
SAE 90 gear oil. (See Adjustments section, page 8).
3. Check the tightness of ttie hut)nuts, 1.e. the large nuts
which hold the hubs or1 to the taper splined shafts.
4. Remove air cleaner coniplete, and flush out with
paraffin or kerosene .(See
Adjustrrients section, page 8).
NUTS AND BOLTS
All nuts and bolts must be kept tight, and as a guide,
the following chart may help.
Nut Sue
a BSW
BSW
gBSW&UNC
BSW b UNC
,? BSW & UNC
; BSW
a BSF
BSF
& BSF
; BSF
BSF
2 BSF
Blade Bolt Nut

EVERY 25 HOURS
LUBRICATE THROTTLE CABLE. GEAR CLUTCH AND
LUBRICATION AND
ROTOR COluTROL PIVOTS, HANDLEBAR SWIVEL AND
SLIDE SHIELD HINGES, DEPTH COhTQOL MECHANISM
EVERY 25 HOURS
CHECK CHAIN TENSION
EVERY 25 HOURS
CHECK GEARBOX 011
EVERY 250 HOURS
DRAIN AND RE-FILL
EVERY 25 HOURS
CHECK CHAIN CASE OIL LEVEL
\@I I
EVERY 250 HOURS
DRAIN, WASH OUT AND RE-FILL
CHAIN CASE
EVERY 10 HOURS
WATCH FOR SIGNS OF UNDUE
ROTOR CLUTCH SLIP
ADJUST IF NECESSARY.
EVERY 25 HOURS
CHECK ALL BOLTS AND NUTS
FOR TIGHTNESS
EVERY I0 HOURS
CHECK FOR BENT BLADES AND
BLADE BOLT TIGHTNESS

MAINTENANCE CHART :;:K::2CSibnpLnvAT~~v~~)
. LEVEL
GEARBOX
E!ERY I0HOURS
(OR TWICE DAILY
IN VERY DUSTY CONDITIONS.)
CHECK AIR CLEANER OIL EVERY
25 HOURS
CLEAN OUT SEDIMENT BOWL.
LEVEL
ENGINE SUMP
:VERY 25 HOURS
IlL ROTOR STUB AXLE
\
EVERY 250 HOURS
CHECK HUB NUTS
FOR TIGHTNESS
\
RECOMMENDED LUBRICANTS
\
EVERY 25 HOURS
CHECK
WEED CUTTER BLADES,
ADJUST IF NECESSARY.
GEARBOX AND CHAIh CASE . ... . 5.A E. 90
ROTOR DOG CLUTCH
ROTOR STUB
AXLE
) US. ENGIME OIL
DEPTH CONTROL WHEEL (IF FITTED)

ADJUSTMENTS
ROAD WHEELS
Each road wheel IS mounted on its hub by a friction
clutch device. These are adjusted so that the wheels
have sufficient grip to pull the machine, but will slip if
they becomejammed wlth an obstruction between the
wheels and the frame.
For normal adjustment, tighten each of the four nutsto
fully compress the springs, then slacken back each nut
half a turn
Should the wheels appear not be driving, check that
the adjustment is correct.
DRIVE CHAIN
Correct drive cha~ntenslon is as Important as correct
lubrication. Total up and down movenlent should be
nomorethan in
(9.5 nim.)to : in. (1 2.5 mm.) Check
wlth a suitahle screwdriver Inserted through the oil
filler hole on the top
side of the chaincase. Turn the
screwdriver to
grlp the cha~nbetween the links. Loosen
the locknut
onthe external adiuster on the bottomfront
of the chaincase, and screw
In the adjl~stln<]screw to
increase chain tenslun Re-t~ghterlt1-i~locknut
CLEANING CHAINCASE
After 250 hours of worh the ctlalncase should be
cleaned out
Unscrew <]I!the bolts securlny the chain-
case to the bdckplate allovv~n<l the chalncase o~lto
dra~nout frorri the jolnt nodrain plug 1s fitted Remove
the cover ensuring that the gasket IS not damaged and
wash out the lnslde of the case and the chaln wlth
petrol or kerosene Re-assemble, and fill wlth ,: pint
( 25 Iltre) SAE 90 gear 011
CLEANING GEARBOX
The gearbox must also be cleaned out after 250 hours
work Unscrew the
dra~nplug on the bottomright-hand
inner side of the gearbox and drain the box immediately
after a period of runnlnq The
011 will bewarm and free-
running and any sedlment will be in suspension in the
oil. Replace the drarn plug and ref111the gearbox with
about
6 pints (3.4 litres) of flushing 011 Runthe machine
for about
3 minutes wlth the rotor well clear of the
ground, then drain the flushing oil. Refill the gearbox
wlth 6 pints (3.4 Iitres) of goodquality SAE 90 gear oil.
ROTOR FRlCTlOlU DRIVE
The rotor to which the blades are bolted is driven direct
frorn the main gearbox through a friction clutch. This
clutch should only operate when the rotor blades strike
an obstacle, when despatched from the factory the
clutch is adjusted so that no slip occurs znder normal
working conditions. If the clutch appears io slip too
easily, it can be adjusted by tightening the four clutch
nutstofully compress
the springs. then slackening back
each nut half a turn.
AIR CLEANER
The air cleaner oilbath oil level must be checked every
10 hours, or every 5 hours In very dusty conditions.
Every
250 hours,the air cleaner lntcrior must becleaned
out. Undo the two nuts
beh~rlcl the air cleaner, to
separate the air cleaner fromthe support bracket onthe
main frame, and undo the jutjllee
clip on the end of the
air cleaner hose to disconnect the cleaner completely.
Remove the black, domed pre-cleaner from the top of
the air cleaner, and flush out the interior of the air
cleaner with paraffin or kerosene, to remove all dirt and
dust frorn the wire gauze elements inslde.
When clean, refit the pre-cleaner and secure the air
cleaner on the support bracket. Re-connect the hose.
MAINTENANCE OF BLADES
Only the cutting edges of the blades should rub in the
soil: the backs of the blades should be clear
The blades are so deslgnecj that use In average so~ls
should keep them sharp. If the <]roundis very stony
however, ~t
IS recon~rnendedthat two sets of hoe blades
be used alternately, so
that one set may be kept
sharpened
The
efficiency of the machine is determlned largely by
the condition of the blades. If they are left bent or dls-
Iorted through strlking solid obstacles in the ground,
they will requlre double the power to drlve. the quality
of the work will bepoor and the blades
will wear much
more quickly. Trouble w~llalso arise with clogging
under the shield Blades must therefore be examined
daily and any bent ones replaced
immediately
ROTOR FLANGE WEEDCUTTERS
Two weedcutter blades are provided, one at each side
of the machine, to prevent longgrass or weeds binding
aroundthe end rotorflanges. The bladesare slotted and
secured bytwosetscrews each, and should beadjusted
so that they just clear the rotor flanges when the rotor
is turned BY
HAND. Severe power losses will occur in
weedy conditions unless these blades are correctly
adjusted.

ROTORS AND BLADES
BLADES
The Howard "Geri~" is normally delivered with the
blades already fitted If it
IS necessary to fit your own
blades, this
IS done as follows:
1. Identify left-hand and r~ght-handblades.
2. The left-hand end flange carries two right-hand
blades.the right-hand end carries twoleft-hand blades.
3 The centre flange (or flanges, depending on the
rnachlne width), carries two left-hand and two right-
hand blades leading The blades should be fitted to the
left-hand side of the centre flange(s), with the heads
I
of the bolts against the blades and spring washers and
nuts against the flange.
PICTINE ROTOR
Inaddit~on, a Pictine rotor, with flanges closer-spaced
than the standard rotor,
IS ava~lablefor use with pic -
tines or pasture renovating (lucerne) tines, for very hard
soil condit~ons,or for pasture renovation. (See Attach-
ments section,
page 10).
TWISTED
BLADE
CUTTING EDGE
R.H. BLADE
How to identify right and left-hand blades.
Gem Rotor (20 in. model), 24 in. and 30 in.
rotors have two centre flanges
BLADE INCORRECT
ALlGNMENl
I
I
3"
3-2 CLEARANCE I
L/J
STRAIGHT EDGE
DIRECTION
OF
TRAVEL
Correct blade setting showing clearance at back of blade.

ATTACHMENTS
FURROWER
DEPTH CONTROL WHEEL
A Depth Control Wheel IS standard with 24 In. and 30 in.
models, but optional, In place of the skid, on the
20 In.
"Gem".
The Furrower is fitted on the depth control skid. Pivut
the depth control lever clipand movethe lever sideways
to withdraw the skid engagement pin. Pull out the skid
from the socket under the rotor shield.
Assemble the furrower onthe skid leaving the furrower
bottom 4 in. (1.25 cm.) above the foot of the skid, or
as required for the crop to be planted, then tighten the
locking nut.
Fit theassembly intothesocltet and connect
to the depth control lever.
For machines fitted with a depth control wheel ~nstead
of a skid, order a skid IP addition to the Currower.
When using the furrower, the rotor is put Into gear so
that cultivating and furrowing are done simultaneously.
PICTINE ROTOR
The Pict~neRotor w~thflanges spaced closer than on
the standard rotor can befitted with
PIC tines or pasture
renovating (lucerne) tines.
The pictines have a horizontal ch~selpo~nt,and are
used for breaking upvery hard ground, old tracks, etc.
The pasture renovating tines have a vertical kn~feedge,
and are used to tear up and aerate old matted turf, to
encourage fresh growth of young grasses.
To fit the pictine rotor, slacken off allthe nutsandbolts
holdingthe support bracket which carries thestubaxle,
staytube and rotor shield. Remove the four rotor clutch
nuts and springs. Spring the bracket off the stub
axle.
using a suitable bar, and slide the rotor sideways to
remove. Then reverse the sequence to fit the pictine
rotor, ensuring that all nuts are correctly tightened and
rotor clutch adjusted.
NOT ILLUSTRATED:-FRONT-END WEIGHTS

MAKING THE MOST OF YOUR "GEM"
GENERAL
As the scope of opct 3tion is so wide, and, as soil ti!lage
methodsdiffer so gre'itly accordingto crop, climate and
soil condition, it is not possibleto deal morethan super-
ficially with this aspect. However, it is hoped that the
following hints will help the user to obtain the best
results from the machine.
The Howard "Gem" will cultivate to a maximum depth
of
9 in. (23 cm.). On certain, especially the heavier,
types of soil, th~sdepth will not be obtained in a single
pass. Where cultivation in depth is needed, afirst pass
shouid be made at
3-4 in. (7-10 cm.), followed by a
fsrther pass at full depth.
The low gear must be used when cultivating ground
which is very hard or covered with heavy growths.
Second gear is usedfor all ordinary cultivation, and top
gear for light cultivation. Always work ~nthe highest
gear that will produce the quality of tilth necessary.
Always use top gear for running the machine between
jobs. A depth control skid or a wheel, is fitted, and by
moving this up and uown the depth of work can be
controiled in
2 in. (19 mm.) stages down to 9 in. (23
cm.) deep.
If the surface of the ground is very hard or baked, the
depth control should be adjusted so that the machine
just bites the surface. Further passes should then be
made until the required depth is reached.
On heavy land which is to be laid upfor the winter, the
surface should be left rough. By using the ridging or
furrowing attachment during this final or late autumn
cultivation, the land can be left in ridges to promote
better drainage and to expose a greater surface area to
the weather.
If heavy land
IS Rotavatedtoo finely and left bare to the
winter rains, the soil may pack together, making spring
cultivations difficult.
When cultivating a ploughed field, the "Gem" should
be run across the furrows, not along them. This will
ensure complete cultivation.
On hilly ground always run the machine around the
contour, working from the top to the bottomof the hill.
After the first cut, one road wheel can be run in the soil
just worked, so that any tendency to slip will be
countered by the wheel coming against awall of uncut
soil.
On light soils, two courses are open. The ground may
either be left rough, or it may be Rotavated to medium
depth and sown to a green crop, e.g. rye. The green
crop will prevent the leaching out of the nitrogen inthe
soil. In the early part of the year the crop is then
Rotavated. After a week or ten days, the spring seed
bed may be prepared. This Rotavation should be
shallower than that used to work-in the green crop.
SEED BEDS
In ground which has been cultivated properly, seed
beds should seldom exceed
2 in. (5 cm.) in depth,
except for certain crops. Seeds require a well-aerated
soil with afirm bottom.Some small seeds requireaseed
bed to be lightly consolidated. This is particularly
important on light soil, where consolidation will bring
moisture nearer to the seedling plant.
Competition from weeds is most critical when the crop
is at the seedling stage. To obtain weed-free seed beds,
thegroundshould be preparedafewweeks ahead ofthe
sowing dates. Rotavation should be carried out at a
depth of
4 In. (1 0 cm.);this causes any weed seeds to
germinate. These weeds may be turned in by a second
Rotavation, which will prepare the seed bed at the
same time. It is most important that this second
Rotavation is shallower than the first. Remember that
the ground is now more open, so that the machine will
tend to dig more deeply. When the seed bed has been
prepared, it should ideally be allowed to settle for
24
hours before sowing.
WEED CON-TROL
Rotavation produces a well-aerated warm seed bed in
which germination takes place readily. Inevitably, such
conditions also favour weed seeds.
Weeds are eliminated by preventing them seeding or by
progressiveweakening
of the deeptap rootsor rhizomes.
Weeds are killed most easily and inexpensively by
Rotavating them directly they show green.Annuals will
be killed outright and perennials will be reduced until
they too, die out. This is true even of such persistent
weeds as couch or twitch.
ROW-CROP WORK
Work will be easier if rowsare madeas long as possible.
At least
3 ft. (1 m.) should be allowed at each end for
turning.
Weeds between rows may be controlled by Rotavation.
Ideally, this should be done when the weeds are small,
but even a heavy growth can be turned in.
This will not prevent weeds growing inthe rows them-
selves; such weeds must be controlled by hand-hoeing
when small. Should land become weed-infested
because these weeds have been allowed to seed, the

following crop should be a cleaning crop, e.g. roots or
potatoes, which will give a period of several weeks in
the early part of the year when the weed seeds will
shoot and can be killed by Rotavation.
In planning your crops to make the best use of the
"Gem", allow
2 or 3 in. (5 or 7 cm.) over the effective
width on each side of the machine.
GREEN MANURING
Land not immed~atelyrequired may be sown down to
such crops as mustard or rye grass during spring and
summer, or rye during the winter. These crops should
be allowed to mature if they are to be used
as green
manures
- they will then have the best effect on the
soil. A winter covercropwill preserve plant foods which
would otherwise be leached away, so it need not be
allowed to mature.
LAND RECLAMATION
The "Gem" may also be used to bring derelict land back
into cultivation.Virgin ground or soil tightly bound with
roots or grass
is best cultivated by fjrst working at only
a shallow depth, to break up the surface. Depth can
then begradually increased bysubsequent passesmade
at intervals of about a week or ten days.
CONCLUSION
Never overtax the power of the machine. Far better
results will be obtained from working in easy stages,
rather than byforcing the machine to dowork inexcess
of its horsepower.
The right to alter and/or amend all designs,specifications and/or prices withoutprior notice is strictly reserved.

Howard Rotavator
r - *'
P<-Y,-:?7 a
A member of the How
Telephone Bury St E-ds (0284 ) 6326