This is a scanned copy of the "Mayfield motor scythe" instruction book.
Instructions
BEFORE STARTING
Fill the sump of the engine with the correct grade of oil, up to the underside of
the filler hole, which is level with the shoulder on the dipstick. Always keep
the sump FULL. Pour some good quality petrol into the tank. Paraffin or Fuel Oil
is useless. Make sure the engine is level. On engines where the oil filler cap
does not have a dipstick fill to brim of filler hole.
TO START
Turn on the petrol by pulling out the tap, or on some engines the tap is turned
on by rotating anti-clockwise. Close the strangler on the carburettor
(when the engine is warm, or in hot weather, it is advisable to start with the
strangler open, as closing it gives a rich mixture and makes starting difficult).
On some carburettors there is a tickler button on top of the float chamber,
if so, depress this for about three seconds to lightly flood the carburettor.
Pull the lever back until compression is felt, and slowly pull the lever so
that the engine is turned just over the compression point, let the lever return
to the original position and pull the lever back sharply in a long swing standing
alongside the machine, and it should fire first or second time,
When the engine fires, open the strangler gradually until the engine runs
smoothly with it fully open. Do not run for a long period with the strangler
closed, as this will cause excessive petrol consumption and carbon deposit,
and may affect lubrication.
On engines fitted with recoil starters, pull the handle so that the engine is
just over compression. Let the handle return and then pull again, and when
the engine fires return the handle back slowly, don't let it fly back.
If the handle is made from rubber, use two hands to prevent it being pulled through
the fingers.
To set machine in motion, compress clutch lever on handle-bars, move gear lever
to No. I position. Release clutch lever slowly, and machine will move forward
under its own power.
On new machines the gear change is sometimes stiff and difficult to engage.
If so, change gear and engage gear without using the clutch. It is essential
however to use the clutch to stop the machine and select neutral.
1st gear gives 1/ 1/4 m.p.h., 2nd gear gives 2 m.p.h., 3rd gear gives 3/ 1/2 m.p.h.
To stop the engine press the shorting clip on to the sparking plug, or press the
small button which is situated at the rear of the fan casing. Turn off the petrol.
HANDLEBAR ADJUSTMENT
There are three positions. To adjust, remove small bolt each side, which fixes
handlebar to stay. Set to required height, and fix bolts in the nearest hole.
WHEN WORKING THE MACHINE
First gear is suitable for heavy growth, while second gear is advised for grass
or similar cutting. Third gear is recommended for driving the machine when
not cutting, and for transporting purposes with wheelbarrow in position.
When cutting tall grass or similar growth it is advised to set the wheels
in the wide position, this allows the cut grass to fall away better.
Alternatively, the cutting blade can be offset, and the swathboard fitted.
In the offset position it is better to set the wheels in the narrow position.
LUBRICATION
Engine.—Check oil level twice daily, top up if necessary.
Drain sump by removing grass cutter mechanism, and tilting machine forward with
filler cap removed, every 50 Hours. On some engines with the filler cap between
the engine and gearbox, there is a drain plug fitted in front of the engine for
draining the sump. If this is not fitted the engine must be removed for sump draining.
Use Castrol XXL in hot weather, XL in normal temperatures.
Gear Box.—Check weekly, and add Castrol XXL if necessary.
Do not overfill. In hot climates use Castrol D. Gear Oil.
Countershaft.—There is one nipple to be greased daily.
It is situated underneath the gear box and is easily accessible by inserting the
grease gun through the space in the lower cover at the rear end of the machine.
Use medium grease.
Wheel Spindle Bearings.—There is one nipple on each bearing.
Grease daily, using medium grease.
Ratchet Hubs.—Chains.—Oil daily (with oil can). Use Castrol XXL.
Vee Grooved Pulley Spindle Bearing.—There is one nipple through
the hole in the middle of the cutter unit frame. On some models there are two grease
nipples, one each side of the frame. Every eight hours, grease the single nipple models
until the grease comes out one side of the bearing. On the models with two grease
nipples grease each one every eight hours with six strokes of the grease gun per nipple.
Use medium grease.
Bell Crank Pivot Bearing.—Grease every four hours until the grease
comes out at the top or underneath the bearing. Use medium grease.
At the bottom end of the bell crank where it operates the cutter bar there is another
grease nipple, grease this every four hours using medium grease. On some machines
the cutter bar can swivel if the locknuts are slackened off and relocked.
If used in this position be sure to grease the bearing underneath the cutter unit
frame every eight hours until the grease comes out at one end. Use medium grease.
Oscillating Mechanism.—There are three nipples. Grease every four hours.
Use medium grease during normal temperatures.During hot weather use heavy or
high melting point grease.
Cutter Bar.—Daily grease block where bell crank locates. Use medium grease.
Oil cutter bar (with oilcan) frequently. On dry sandy soils it is better to let
the cutter bar run dry. The cutter bar may not cut any better for efficient lubrication,
although wear will be reduced considerably except under conditions mentioned above.
CHAIN ADJUSTMENT
Primary Chain.-I.e., chain between engine and gear box. Remove lower
cover when adjusting any chain.Slacken the two nuts underneath the gear box
Unscrew the locknut on the setscrew which is between the engine and gear box
several turns. Now turn this setscrew, which will push the gear box backwards,
and thus tighten the chain. When tension is corrcct, there should be 1/2in.
to 3/4in. free up and down movement when the chain is in its tightest position.
Tighten up nuts underneath the gear box, and re-tighten locknut on the
adjusting screw.
Secondary Chain.-I.e., chain between gear box and countershaft.
Unscrew the nut on the gear box adjusting bolt, underneath the frame (rear end)
several turns. Now turn the nut on top of the frame, on the gear box adjusting bolt.
This raises the gear box platform and tightens the chain. There should be 1/2in.
to 3/4in. free movement when the chain is in its tightest position. Tighten
up nut on the gear box adjusting bolt underneath the frame. On Mk. 20 models
there is a setscrew on the LH side at the rear end of the gearbox platform.
When the secondary chain has been correctly adjusted this setscrew should be
screwed down until it touches the frame, and then locked in position. This
setscrew prevents undue strain on the gearbox platform adjusting bolt.
Final Drive Chain.-Slacken the two nuts underneath the countershaft
bearing bracket. Unscrew the 1/4in. lock nut on the adjusting screw several
turns. Turn the adjusting screw which pushes the countershaft bearing bracket
backwards and tightens the chain. As this is a short drive, there should only
be 1/4in. to 1/2in. free movement when the chain is in its tightest position.
Re-tighten nuts underneath the countershaft bearing bracket, and also the
locknut on the adjusting screw.
CLUTCH ADJUSTMENT
Slacken locknut on the cable adjuster on top of the gear box. Now unscrew
the adjuster to take up the slack in the cable until the slack is only
1/32in. to l/l6in. measured at the clutch lever on the handlebars
Tighten the locknut after adjusting. It is essential to have this small
amount of slack in the cable otherwise the clutch is liable to slip, and
will make starting the engine with the starting lever impossible.
The slack in the cable can also be taken up as follows:- disconnect the cable
on the clutch operating arm on the gear box. Swing the arm back and remove the
plunger. Screw in the setscrew on the plunger one-third of a turn at a time.
Replace to see if it is sufficient or too much. A little adjustment at this
point alters the position of the arm considerably.
If clutch slip occurs and makes starting difficult when it is correctly
adjusted, this is due to the oil on the clutch corks. This is not serious,
and if the operator can start the engine with a rope no harm will be done
to the clutch using it in this condition. To cure this fault the corks
can be washed in petrol and the surface of them roughened up with glass-
paper but even this is not a 100 per cent cure and relining is advisable.
Factory exchange service clutches are available.
WHEELS
Keep the tyres hard (50 lbs. per square inch), this reduces vibration to a
minimum To lock the wheels to the wheel spindle which is recommended when
descending steep slopes, proceed as follows:- It may be advisable to only
lock one wheel, as this will stop the machine running away down hill and
yet turning will be easier than if both wheels are locked. If the LH wheel
only is locked, turning to the left is easy and if the RH wheel is locked
turning to the right is easy.
On some machines there is a small rectangular pin held in place by a clip.
Loosen the engine nut holding the clip, and the pin can be withdrawn.
Turn the clip away and there is a 5/16" dia. hole, turn the wheel forward
and after each "click" look to see if the pawl is visible, when it is,
insert the rectangular pin fully and this locks the wheel. Swing the clip
back over the hole, which retains the pin and tighten up the wheel nut
On older machines wheels are locked by a locking plate with two 1/4in dia.
pins held on by two wheel nuts, or one central screw. These are used as follows.
Remove the locking plate and turn the wheel forward, so that the two 1/4in dia.
holes on the outer hub plate line up with two more 1/4in dia. holes inside.
When they do push the locking plate into position with the pins in the holes,
and replace the two nuts or the central screw, as the case may be.
When traversing across steep slopes it is recommended to reverse each wheel.
As the rims are dished this increases the track by eight inches.
On each side of the wheel bearings there is a collar. After a good deal of use
or if the spindle bearing lubrication has been neglected there will appear a
little wear at this point, and even 1/32" will cause excessive vibration when
the cutter bar is fitted. To rectify this wear remove the grubscrew, turn the
collar through 180 degrees, re-dimple the spindle through the tapped hole in
the collar, using a 1/4" diam. drill, while both collars are as close as possible
to the side of the bearings and then re-fit the grubscrew. As the wear is usually
so small only one collar need be re-positioned. If both collars have worked
loose the final drive chain must be lined up if both collars need re-positioning.
CUTTER UNIT
This can be removed quickly by unscrewing the two nuts in front of the engine
and lifting the whole unit off. When replacing don't forget to put the V belts
in position at the same time. The V belts should always be removed or placed in
position in this way. On no account should they be stretched over the pulleys.
Should the V belts become slack special "C" washers can be supplied to put
underneath the engine to tighten the belts. On some machines the belt tension
is adjustable as follows:- Loosen the locknuts at the top of the frame, and
slacken the two clamping nuts on the Tractor half a turn. Adjust the two
setscrews equally so that the belts get tighter and are in line with
the pulleys.
It is not necessary to have the belts too tight as they will drive satisfactory
just taut. Tighten the two locknuts after adiusting, and tighten the two clamping
nuts on the Tractor.
When fitting the cutter unit with adjustable belts always make sure it is replaced
correctly with the vee grooved pulley in line with the engine pulley, and the
adjusting screws touching the frame.
TO CHANGE FROM CENTRAL TO OFFSET
CUTTING
Unscrew the three locknuts underneath the three setscrews that secure the
finger bar to the frame, and then unscrew the three setscrews to enable the
cutter bar to be removed. Remove the two knife clips on the right hand side
and slide out the central blade. Slide the offset blade in position. Remove
the three setscrews at the right hand end of the finger bar. Now attach the finger
bar to the frame in the offset position, care being taken to position the curved ends
of the swivel block so that they touch the faces of the knife bar block. The flat
faces of the swivel block face front and rear. Use the long setscrews taken from
the middle position on the finger bar. Now use the three short setscrews taken
from the end position, and screw these in the three central holes of the finger bar.
Replace the knife clip on the right hand side nearest the centre, and replace nuts
on the finger bolts, where extreme right hand knife clip was positioned (if these
nuts had to be removed).
If the machine will be used mostly in the offset position, it is advisable to
remove all the knife clips except the one on the extreme left. These three knife
clips can then be repositioned along the finger bar, so that there is a total of
four knife clips, as when the blade is in ihe central position. When knife clips
are repositioned, it is essential to reposition the wearing plate under the knife clips.
SWATHBOARD
It is advisable to use this item when cutting in the offset position. It sweeps
the cut grass away from the uncut grass, so that a clear path of about 6in. wide
is left. This prevents any of the cut grass clinging to the end fingers on the next cut
It is attached by removing the two setscrews on the end of the finger bar, and
fixing the holding bracket there. The staff attached to the swathboard can be
adjusted to suit the height of the grass being cut. It should be in a position
to push the cut grass over.
Do not forget to tighten the locknut on the setscrew after adjusting staff position.
When the cutter bar is fitted with knife clips which are held in position with one
nut between the two guards (fingers), it will be necessary to move the knife clip
on the extreme left, to between the second and third guard from the left, or turn
the adjusting setscrew, so that the head underneath the clip rests on top of the
swathboard holding bracket.
CUTTER BAR ADJUSTMENT
To obtain best results the knife should be kept sharp and correctly adjusted.
To remove the knife, unscrew the three locknuts underneath the three setscrews
that secure the finger bar to the frame, and then unscrew the three setscrews
so that the cutter bar can be removed.
Remove two knife clips on one side (if centrally mounted) and slide Out the knife.
If the blade is offset, the knife can be pulled out without disturbing the knife
clips. On no account lever the ball end of the bell crank out of the knife bar block.
When resharpening the knife. always file or grind bevelled side only, and keep the
sloping sides symmetrical. The ledger plates in the fingers cannot be sharpened,
but it is advisable to remove any burrs caused by stones or other obstacles.
When replacing knife bar clean the fingers thoroughly, and oil all the sliding
surfaces. The knife clips should keep the knife bar pressed down without causing
undue friction.
The knife clips arc adjustable as follows:-
Turn the setscrew at the back of the knife clip, the head of this screw is
underneath the knife clip. Turning one way will press the head down harder on
the knife, and the other way will increase the gap. When correctly adjusted the
knife will slide easily and the gap between each knife clip head and the knife
will be a minimum. Tighten the central nut after adjusting and make sure the knife
still slides easily.
It should be possible to turn the pulley by hand easily when the knife clips
are correctly adjusted. If the adjustment is too tight, it will be difficult or
impossible to start the engine. On the other hand if the knife clips are not
adjusted when necessary this results in bad cutting and causes excessive vibration.
OSCILLATING MECHANISM
This is correctly adjusted on all new machines before leaving the works. and
if lubricated as instructed, should not need any further attention.
There are three bearings in the mechanism, thus forming a universal joint.
These three bearings are of ample size, and wear will not take place unless
lubrication is neglected. Should any wear develop, have new bushes fitted immediately,
to save further wear or damage.
The overall length of the mechanism is adjustable. This is necessary so that the bell
crank can be made to swing equally on either side, so that each knife section moves
from the centre of one finger to the centre of the next finger. This is important
for efficient cutting.
To effect this adjustment it is necessary to remove the split pin and unscrew
the nut on the bell crank, and slide off the bearing block of the mechanism.
Slacken the locknut on the special bolt, and the lower part of the mechanism
can be turned backwards or forwards as necessary. Place in position and pull
the starting lever over to make sure adjustment is correct. Be sure to see the
grease nipple on the bearing block is on top, and don't forget to tighten the
locknut after adjustment.
It is absolutely essential to fit the oscillating mechanism on the correct way.
That is, the bearing block with only one bearing bush goes on the eccentric end
of the pulley spindle.
The special bolt has a disc head, which is enclosed in the fork. Between the
bolt and the bottom of the hole in the fork is a rubber disc. Fitted over the
bolt is a rubber collar, and this is retained in the fork by a gland nut.
The object of this assembly is to act as a shock absorber should the knife be
stopped suddenly by an unseen obstacle.
It is essential that the special bolt is retained tightly in the fork,
and new rubbers should be fitted if this is not so.
On some machines this mechanism has been superseded by a connecting rod which
is not adjustable, and does not contain a shock absorber. With these models the
vee belts are adjustable, and they must not be too tight, but just taut enough
to drive efficiently, so that if an obstacle causes a stoppage by jamming the
knife, which in turn stops the engine, the vee belts will slip slightly and
save damaging the engine and operating mechanism.
INSTRUCTIONS FOR USING HOEING AND
CULTIVATING EQUIPMENT
For hoeing row crops it is strongly advisable to fit the tool frame on the front
of the tractor by means of the frame extension. Place the tool frame the correct way
so that the ends are roughly in line with the wheels. Attach the hoe blades with
the stalks adjacent to the plants. Attach the depth control skids so that the blades
pass under the soil at the required depth.
For cultivating fit the toolframe on the rear of the tractor and space the four
cultivators as required. Be sure to attach the balance weight on the front of the
tractor. When cultivating it may be found beneficial not to use the depth control skids.
STANDARD MACHINES (18 in. track)
For l2in. and i4in. wide rows reverse both wheels so that track is 26in. Straddle
two rows, but only hoe one row unless two rows were drilled at once.
For l6in., l8in. and 2Oin. wide rows, keep wheels in narrow position.
For 22in. and 24in. wide rows, reverse one wheel.
For 26in. and 28in. wide rows, reverse both wheels.
For 3Oin. wide rows and above keep wheels in narrow position and use as
an inter-row machine.
WIDE AXLE MACHINES (22in. track)
For l2in. and l4in. wide rows reverse one wheel and straddle two rows.
Only hoe one row unless two rows were drilled at once.
For l6in. wide rows reverse both wheels and straddle two rows.
Only hoe one row unless two rows were drilled at once.
For l8in., 2Oin., 22in. and 24in. wide rows keep wheels in narrow position.
For 26in., 28in. and 30in. wide rows reverse one wheel.
Above 3Oin. wide rows keep wheels in narrow position and use as an inter-row
machine.
When using the machine for inter-row hoeing use the two side hoes with the stalks
in the wide position and use the sweep hoe blades in the middle.
When hoeing on the front it may be found advisable to walk in the next row to
be hoed. This saves treading on the work and one can see the hoe blades better.
Steering is very simple with one hand.
Standard cultivating equipment is only intended for one row. If two rows need
to be worked additional blades will be necessary.
N.B.-With all rear mounted attachments including the trailer it is essential
to fit the front balance weight. Separate instructions are issued with Lawn Mowing
and Spraying attachments.
INSTRUCTIONS FOR FITTING AND USING THE
PLOUGH ON THE MAYFIELD TRACTOR
Please note when describing the Left Hand side or Right Hand side, it is
assumed one is standing between the handlebars facing forward.
If the soil is heavy or hard, we strongly advise the 90lb. adjustable balance
weight, and Wheelstrakes fitted on each wheel.
Attach balance weight to the front of the tractor.
Attach Frame attachment bracket at the rear end of the tractor. This bracket
is painted red, and the long slot formed by the two pieces of steel should be below
the two 1/2" nuts.
Attach the handlebar bracket to the handlebars, and clamp in place with the hook,
so that the bracket is parallel to the crossbar.
Set the disc coulter on the plough as follows.
The lower edge of the disc should be 1/2in. to 1in. above the point of the
plough share.
The disc should be 1/2in. approximately away from the landside edge
of the plough i.e., the straight side; it should not be over the mould board.
The above dimensions are for clean soil. If weeds are prevalent these
dimensions should be increased slightly.
Make sure the clamp is in the correct position before tightening.
The force tending to push the disc backwards when ploughing, also tends to
turn the clamp on the plough beam. When in the correct position the clamp is
diagonally on the plough beam, and the disc being forced backwards cannot turn
the clamp any further.
The distance of the disc from the landside is easily adjusted by the nuts on
the clamp.
As the disc stem is clamped to the curved surface of the plough beam,
loosening the top nut and tightening the bottom nut moves the disc away from
the landside, and loosening the bottom nut and tightening the top nut moves the
disc nearer the landside.
Now attach the plough by fitting the tongue at the front end of the plough
into the long slot on the frame attachment bracket, so that the plough is central
between the wheels. Insert the bolt, and screw on the nut underneath but not too
tightly. The tongue on the plough must be free in the slot.
Attach the two long atrips on the plough, to the handlebar bracket (one each
side) and adjust the L.H. one with several holes so that the round crossbar on
the plough is level.
Adjust the clamps on the crossbar so that the plough is straight. The plough
should now be in the middle of the wheels (approximately) and the landside
at a right angle to the wheel axle.
This is now ready for cutting the first furrow, and the handle will have to
be turned to adjust the angle of the plough, to give the best results on the
soil conditions encountered.
Cut the first furrows along the outside edge of the area to be ploughed.
If it is a large field. to save wasted time turning at the headland, divide the
plot into equal size areas, and cut the first furrows along the outside edge
of each area. When the plot is flat plough along the longest side. When the plot
is hilly or on a slope it is best to get advice locally from an experienced man.
After one has cut the first furrow. the plough needs resetting.
The R.H. wheel of the tractor will now run in the gully of the first furrow,
so that the axle will be sloping downwards towards the furrow.
We have now got to adjust the plough so that it is level, and also move it
from between the middle of the wheels to ihe left side of the R.H. wheel in the
furrow.
To accomplish this loosen the nut on the right of the handlebar bracket,
and remove the bolt holding the strip with several holes. Remove the bolt on
the frame attachment bracket and fit the tongue in one of the holes nearer
the R.H. wheel, so that the landside of the plough is about 4in. left of the
inside edge of tbe R.H. wheel.
Refit the strip with several holes so that the crossbar of the plough is level.
Position the plough on the crossbar, so that the landside edge trails a
little to the left, and tighten both clamping collars.
The plough then acts as a rudder on a boat, and tends to make the R.H. wheel
in the furrow try and climb out.
TOOL KIT
To avoid the purchaser paying for tools which he most probably already possesses,
only special spanners and a grease gun are provided.
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