Ransomes MINOR MK. 7 Operation and maintenance manual

Publicaon A 16752 G
INSTRUCTIONS
FOR THE
OPERATION AND MAINTENANCE
OF
MINOR MK. 7
MOTOR LAWN MOWERS
RANSOMES SIMS & JEFFERIES (AUSTRALIA) PTY. LTD.
CLAYTON VICTORIA

2 RANSOMES SIMS & JEFFERIES (AUSTRALIA) PTY. LTD.
GENERAL DESCRIPTION
ENGINE.
This model is equipped with the Villiers 98 cc. two-stroke engine, fied with a kickstart.
Maintenance of Engine. If trouble is experienced when starng the engine through the
sparking plug becoming wet and oily, the crank case should be drained by taking out the
small plug which will be found at the base on the le-hand side of the crank case. This
trouble occurs through overflooding of carbureor or by leaving the petrol turned on when
the machine is not in use, allowing the oil to sele in the carbureor.
The engine should be decarbonised at the end of each season. All carbon should be
thoroughly cleaned off piston, cylinder head and exhaust port. When replacing, care should
be taken to replace the piston correctly, i.e., the sloping side of top towards the exhaust
port or front of engine. The silencer and exhaust system should also be cleaned out.
CLUTCHES.
All models are fied with a centrifugal clutch in the engine sha and a fricon plate land roll
clutch controlled from the handles.
Main Driving Clutch (see illustraon page 14): This clutch is of the automac type and
comes into operaon as the engine speed increases. To delay the acon of the centrifugal
clutch shoes (P), springs (Q) are fied which allow an engine speed of up to 500 r.p.m.
without engagement. As the speed increases from this, the clutch shoes gradually take up
the drive. Should an overload be put on the clutch, the tendency will be for the clutch to pull
the engine speed down and then slip without stalling the engine. The clutch shoes are lined
with bonded ferodo lining and can be easily detached when relining is necessary. It is
essenal to use the correct lining and method of riveng for this purpose. When replacing
the shoes, care must be taken to see that the hinged ends of the shoes point towards the
direcon of running.
- Land Roll Plate Clutch (see illustraon page 3): This clutch will allow the cung cylinder to
remain under power whilst the land roll is disengaged from the engine. The land roll clutch
should always be disengaged when starng the engine or when leaving the machine with
the engine running.
Note: Clutch life will be prolonged if plates are kept slightly oily.

RANSOMES SIMS & JEFFERIES (AUSTRALIA) PTY. LTD. 3
Figure 1 - Land Roll Plate Clutch
LUBRICATION.
RECOMMENDED LUBRICANTS.
SHELL Two Stroke Motor Oil
VACUUM Mobil Mix TT
WAKEFIELD Castrol XL
C.O.R Energol Motor Oil SAE30
CALTEX Two Stroke Motor Oil, Medium
AMPOL Two Stroke Oil

4 RANSOMES SIMS & JEFFERIES (AUSTRALIA) PTY. LTD.
LUBRICATION OF ENGINE.
All lubricaon to the engine is provided by mixing the lubricang oil with the petrol, and this
is taken in through the carbureor to the crank case, from which the main bearings, piston
and cylinder walls are all automacally lubricated. The mixture we advise as most suitable is
20 parts of petrol to 1 part of the best oil suitable for air-cooled engines, i.e., 1 measure of
oil to I pint of petrol. With a new engine the rao should be increased to approx. 16 to 1 for
the first 25 working hours, i.e., approx. 11 measures to 1 pint.
It is important that oil and petrol in the correct proporons should be mixed in a separate
container or petrol can before pouring into the fuel tank. Just sufficient fuel for immediate
use should be mixed, as stale mixture is liable to make it difficult to start the engine.
LUBRICATION OF MACHINE.
(Illustraons pages 7, 8, 9).
Parts to be oiled each me the machine is used.
1. Clutch sha bearing through nipple (A).
2. Land roll spindle bearings through nipples (B) in housings.
3. Land rolls, through nipples (C) which will be found through surface of each roll.
4. Cung cylinder bearings through nipples (D).
5. Land roll clutch through nipple (G) in outer plate. Remove the chain cover to expose
this nipple.
6. Starng free wheel. A LITTLE oil through the nipple in flywheel.
7. Kickstart Spindles.
8. Wood Rolls can be oiled between the rolls and at each end.
All other oiling points such as chains and kickstart bearings should be oiled weekly.

RANSOMES SIMS & JEFFERIES (AUSTRALIA) PTY. LTD. 5
OPERATION
TO START ENGINE.
1. Fill up with correct mixture (see above). It is best to mix the petrol just before using,
and not more than is required for immediate use. An old petrol n will be found
useful for mixing purposes. On no account should the mixture be made up in the
tank.
2. See that the land roll drive clutch is disengaged.
3. Pull out petrol cock at underside of tank and flood the carbureor by depressing the
ckler.
4. The posion of control lever on right handle of machine for starng should be
slightly open.
 To open throle or admit gas to the engine, the control lever should be moved in
a clockwise direcon; the reverse direcon closes the throle.
5. Close choke on cold days, kick engine over smartly when the engine should start in
two or three turns.
6. Aer the engine is running, the posion of control lever can be adjusted to give
required speed of engine and 'the choke opened.
FAILURE TO START.
If the engine will not start aer a reasonable number of trials, ascertain whether this is due
to lack of compression, faulty fuel supply, or faulty ignion.
FUEL SUPPLY.
Depress ckler at side of carbureor body. If fuel is reaching float chamber it will spurt out
of vent at top of ckler. It is important that the venlang hole in the filler cap of the fuel
{tank should not be allowed to become choked up.
IGNITION SYSTEM.
Unscrew sparking plug from cylinder head and place it, with ignion cable aached, on a
metal poron of the engine. A spark should be visible at the plug points when the engine is
rotated if the plug and ignion system are in order. If there is no spark, try a new plug, or
alternavely, check whether a spark occurs at the end of the ignion cable when this is held
about one-eighth inch away from a clean metal part of the engine.
If the engine will not start aer these preliminary tests lt the machine back on its handles
go that the drain plug on the engine crankcase is directly under the cranksha. Remove
drain plug and drain off any oil which may have accumulated in the crankcase.
If aer this the engine will not start, a more detailed examinaon will be required.
Compression should be felt when the engine is rotated at normal starng speeds with
throle partly open.

6 RANSOMES SIMS & JEFFERIES (AUSTRALIA) PTY. LTD.
TO OPERATE MACHINE.
The machine can be operated either by driving on the land roll clutch, or by leaving the
clutch engaged and driving with the throle lever over the centrifugal clutch. The laer
method is most convenient for straighorward cung and the former method for difficult
condions, involving blind ends, etc.
To drive on land roll clutch, allow engine to warm up, increase engine speed, then engage
clutch slowly at the same me opening throle. Let clutch fully in and the machine should
glide forward. Open or close the throle to achieve a comfortable walking speed. To stop
the machine, disengage the clutch and close throle. When leaving the machine with the
engine running, in order to empty the grass box or for any other reason, throle down unl
the cung cylinder stops revolving, otherwise the rotang cylinder will tend to bruise the
grass.
To drive on the centrifugal clutch and throle, allow the engine to warm up, then reduce
engine speed unl the clutch sha stops revolving. Engage the land roll clutch and the
machine can then be controlled solely by the throle lever.
Speeding up of the engine will bring the centrifugal clutch into acon and consequently the
machine will move off. By reducing engine speed, the machine will come to a standsll.
With a very lile pracce it will be found that manipulaon of machines with this self-
energising clutch becomes very simple with an exceponally smooth take-off, especially
when stopping and starng in long grass.
For safety purposes, the land roll clutch should be disengaged if the machine is to be le
standing for such things as emptying of the grassbox, etc. The machine should be driven at a
comfortable walking pace and can be operated and adjusted enrely to suit the individual
requirements for all classes of cung. Do not try to help the machine to do its work, but
simply hold it steady and watch the cung to get a regular and even cut.
ADJUSTMENTS.
ADJUSTING THE KNIVES.
Each machine is sent away with the cung cylinders properly set to the boom blade, but it
is possible they may be upset during transit to the user. When the machine does not cut
perfectly, set the cung cylinder carefully to the boom blade, so that the revolving cuers
just touch the boom blade throughout the whole length and without causing any friconal
pressure.
For seng the knives a simple method is used, viz.: —adjusng screws (K) (see illustraon
page 9) on either side of machine.
To set cung cylinder closer to boom blade, turn in clockwise direcon. It is advisable
when adjusng to make a small adjustment to each screw alternately.
When correctly set, the knives should revolve freely and at the same me be able to cut a
leaf or piece of wring-paper held at edge of the boom blade. This test should be made
over the enre width of blade.

RANSOMES SIMS & JEFFERIES (AUSTRALIA) PTY. LTD. 7
If the cung cylinder is set hard on to the boom blade no cleaner cut is obtained, but
extra work and undue wear is put on to the machine.
Aer adjustments make sure that the cung cylinder chain is not too ght.
CAUTION. Never touch the cung cylinder or chains when the engine is running.
TO ALTER THE HEIGHT OF CUT.
Slacken the nuts (H) (see illustraon below) and move brackets up or down as required
lining up the pointer on the brackets with the dimples in the side frame.
CAUTION. The machine should never be used with 'the boom blade pressing on the lawn.
If it does, the spiral cuers are liable to be damaged by the boom blade being forced
upwards; the machine will also work heavily, and the turf will be badly marked. It is a fallacy
to think that grass is cut shorter by having the blade hard on or touching the ground. If the
blade is just clear of the ground, it does not press the grass down and a cleaner cut is made.
Figure 2

8 RANSOMES SIMS & JEFFERIES (AUSTRALIA) PTY. LTD.
To check that the height is correctly set, lt the machine backwards unl it rests on its
handles, place a straight edge across the land and front rolls; the boom blade should then
be clear of the straight edge. In dry weather, in. to in. and in wet weather, in. to in.
clearance should be allowed for the machine sinking into the turf.
HANDLE ADJUSTMENT.
The height of the handles can be adjusted to suit the user. Slacken the bolts at the boom
of the handles, alter the height of handles as necessary and re-ghten bolts.
Figure 3

RANSOMES SIMS & JEFFERIES (AUSTRALIA) PTY. LTD. 9
Figure 4
TRANSMISSION CHAINS.
These are both adjusted by posioning the land roll plate clutch. To adjust, disengage the
clutch by liing the clutch lever, rotate the outer plate unl the two holes line up with the
two holes in the nut beneath, insert pin spanner provided and turn an-clockwise to slacken
nut, slide the clutch bodily to ghten chains and then re-ghten nut. When adjusted the
chains should be slightly slack in all posions.
If at any me a chain is removed, take care when replacing that the gap in the spring clip
points away from the direcon of rotaon.
LAND ROLL CLUTCH.
Adjustment is provided at the lower end of the Bowden cable. When adjusted correctly
there should be a small amount of play between the end of the operang pin and lever
when the clutch is disengaged, i.e., the clutch should drive firmly when engaged and be
completely free when disengaged.

10 RANSOMES SIMS & JEFFERIES (AUSTRALIA) PTY. LTD.
MAINTENANCE.
ENGINE.
If trouble is experienced when starng the engine through the sparking plug becoming wet
and oily, the crank case should be drained by taking out the small plug which will be found
at the base on the le-hand side of the crankcase. This trouble occurs through over-flooding
of the carbureor or by leaving the petrol turned on when the machine is not in use,
allowing the oil to sele in the carbureor.
DECARBONISING.
Decarbonising the Villiers Two-Stroke Engine is quite straight forward, because of the
simplicity of this type of unit. The following points, however, are worth special aenon.
When removing and replacing the cylinder, care should be taken not to twist it round the
piston — it should be pulled off or pushed on straight so that the rings cannot catch in any
of the ports and break.
All carbon should be removed from inside the piston head, as well as from the top of the
piston and the cylinder head.
The ports in the cylinder, parcularly the exhaust port, should receive careful and should be
kept clean, but on no account must the size or shape of these ports be altered by filing.
Piston ring grooves must be kept free from carbon in order to leave the rings quite free.
Piston rings should be bright round their surface which makes contact with the cylinder
bore. Should wear cause the joint gap to exceed in. when in the cylinder, the piston ring
should be replaced.
Carbon will form on the gudgeon pin at either side of the small end bush, and should be
carefully removed, otherwise difficulty will be experienced in removing the pin from the
piston. The small end bush and the piston bosses should be kept quite free from carbon.
It is of the utmost importance that silencers and exhaust pipes are kept quite clean
internally, and that a heavy deposit of carbon is not allowed to accumulate. This would
cause back pressure and of power.
It is important that air leaks should be avoided. The connecon between carbureor and
inducon pipe must be absolutely airght and aer dismantling the engine, new washers
should be fied at the inducon pipe joint and cylinder base joint if the original ones have
been disturbed.
The engine should be decarbonised at the end of each season.
VILLIERS JUNIOR CARBURETTOR.
This is of the concentric float chamber type, allowing the machine to be worked on
undulang grounds without affecng the running of the engine.
In this carbureor, a taper needle is aached to the throle and provides a correctly
adjusted mixture at all throle openings.

RANSOMES SIMS & JEFFERIES (AUSTRALIA) PTY. LTD. 11
The carbureor is set at the Works before delivery, but if it is desired to make adjustment at
any me, proceed as follows:
1. First remove the throle by unscrewing the top ring of the carbureor.
2. At the top of the throle there is a small screw. Turning this in a clockwise
direcon lowers the needle and will give a weaker seng. Turning the screw in
an an-clockwise direcon will give a richer seng.
3. For adjustment give approximately half a turn at a me unl a correct seng is
found.
If the float cup has to be removed at any me for cleaning, etc., do not use too much force
in ghtening the boom nut when re-assembling.
Periodically gee that the gauze in the petrol connecon is free from dirt. This gauze is fied
to the bolt which aaches the petrol pipe to the carbureor.
IGNITION.
MAGNETO TIMING
If at any me the flywheel magneto is removed from the end of the cranksha, care must
be taken when replacing to check the relave posion of the flywheel to the piston posion.
The back or armature plate is held by two screws and the drain hole should be at the
boom. Great care must be taken in posioning the flywheel itself. The magneto is med to
give a spark when the piston is in. before top dead centre with the points commencing to
open. When building the engine, the ming is set as shown, flywheel ghtened on sha,
then rotated unl piston is at top of stroke. Two ming marks are then punched directly
opposite one another, one on the boss on the armature plate and the other on the flywheel
rim.
FLYWHEEL REMOVAL.
The cam operang the contact breaker is riveted to the flywheel which is driven by a taper
on the cranksha, and if alteraon to magneto ming is necessary, the flywheel must be
released, by unscrewing the centre nut with a special hammerght spanner which can be
supplied. This nut has a right-hand thread and is imprisoned in the flywheel, and it should be
unscrewed unl the flywheel is just free to revolve on the cranksha. With the piston at top
of stroke the flywheel should then be moved round unl the ming marks are in line, then
ghten up the nut firmly and re-check ming. This nut must be ghtened up hard by hing
with a hammer on the end of the spanner.
The taper of sha and cam must be clean and dry; if any oil is present on the surfaces, it will
be impossible to secure an effecve drive.
MAGNETO ADJUSTMENTS.
The magneto is built into the flywheel. To adjust the contact breaker points (H) (see
illustraon page 12), the cover must be removed. Having removed the cover rotate the
flywheel to see if the points open and close correctly.

12 RANSOMES SIMS & JEFFERIES (AUSTRALIA) PTY. LTD.
If the rocker arm (K) appears to be ght, remove it from its bearing and thoroughly clean the
pin. A lile oil should be smeared on the bearing when re-assembling. Providing the contact
breaker points are kept clean, and above all, free from oil, they will probably need
adjustment only at long intervals. When the points are fully open, the gap should be .015-
inch. If adjustment is necessary, slacken locknut (M) and turn the contact screw (N) unl the
gap is set to the thickness of the gauge aached to the magneto spanner; then screw up the
locknut again unl it is firmly locked.
Figure 5 - Contact Breaker
H. Contact Breaker Points. K. Rocker Arm.
M. Contact Screw Locknut. N. Contact Screw.
SPARKING PLUG.
Clean and reset the points .025-inch gap aer each 100 hours operaon.
Adjustment of the gap should be done by moving the points aached to the outer body of
the plug. Never bend the centre pin. Keep the outside of the plug insulaon free from water
and dirt. When screwing the plug in the cylinder head, should any undue sffness be
experienced do not force but examine thread for any parcles of grit or carbon which may
be present. These must be removed, otherwise the threads in the cylinder head may be

RANSOMES SIMS & JEFFERIES (AUSTRALIA) PTY. LTD. 13
damaged. It is a good plan to smear a lile graphite grease on the plug threads before
replacing.
AIR CLEANER.
The air cleaner should be periodically examined and cleaned; when used under very dusty
condions frequent inspecon is necessary. Running the engine with a choked air cleaner
causes a very rich mixture to be drawn into the cylinder.
The cleaner should be washed every 100 hours or sooner, depending on dust condions. To
do this remove and submerge in petrol. Rinse and then dip c in engine oil.
HINTS AND TIPS.
1. Always thoroughly mix the oil and petrol before pung in tank.
1. 2. It is wise to filter your petrol mixture through a fine wire gauze when pung in
tank.
2. Do not flood carbureor before starng when the engine is warm.
3. Stop engine by turning off fuel tap if engine is not to be used for several days.
4. Do not experiment with cheap sparking plugs—use type recommended.
5. Crank shas should only be taken apart by a skilled mechanic. Special tools are
required for ensuring alignment when re-assembling and as the makers have these
facilies, repairs can be undertaken by them at the lowest cost.
6. It is important that air leaks should be avoided at the following points :-—
(a) Between inlet pipe and cylinder.
(b) Between inlet pipe and carbureor.
(c) Between cylinder base and crankcase.
(d) Between the two halves of crankcase.
7. When decarbonising the engine it is very important that silencers and exhaust pipes
are also cleaned out.
8. Avoid all sharp bends in the carbureor control cables.
TO REMOVE LAND ROLL ASSEMBLY.
Remove chain case cover, remove land roll clutch assembly complete with chains. Unscrew
chainwheel on land roll spindle (note—Le Hand Thread). To prevent the land roll spindle
turning with the chainwheel, engage a key, Whig) can be provided, in the slot at the
opposite end of the spindle. Aer removing the six setscrews (three on either side of the
machine) which secure the land roll spindle bearing, the enre assembly may be dropped
out of the main shell. Assemble in the reverse order.
TO REMOVE WOOD ROLL ASSEMBLY.
Loosen off height adjusng nuts and drop wood roll spindle unl clear of the main shell.
Loosen socket screws in both adjusng brackets and draw out wood roll spindle. If it is
desired to remove the adjusng brackets, undo the height adjusng nuts and withdraw the
brackets from their pivot pins. Assemble in the reverse order.

14 RANSOMES SIMS & JEFFERIES (AUSTRALIA) PTY. LTD.
Figure 6 - Main Driving Clutch
TO TAKE CUTTING CYLINDER AND BOTTOM BLADE UNIT OUT OF MACHINE.
Remove chain case cover, concave, and chains. Unscrew the pinion securing screw by
turning clockwise. Prevent the cylinder turning by placing a piece of wood in cuers and
unscrew the pinion (L.H. thread). Remove the two screws on each side securing the cung
unit and the enre assembly can be dropped out of the machine.
WRITE TO THE MAKERS.
If anything goes wrong that you cannot correct, communicate at once with the Distributors
who supplied the machine or with Ransomes Sims & Jefferies (Australia) Pty. Ltd., Clayton,
Victoria.
Note. When ordering spares always quote registered number of the machine.