O.S. engine MAX-12CV-R Setup guide

It is of vital importance, before attempting to
operate your engine, to read the general
'SAFETY INSTRUCTIONS AND WARNINGS'
section on pages 2-5 of this booklet and to strictly
adhere to the advice contained therein.
•Also, please study the entire contents of this
instruction manual, so as to familiarize yourself
with the controls and other features of the
engine.
Keep these instructions in a safe place so that
you may readily refer to them whenever
necessary.
It is suggested that any instructions supplied
with the vehicle, radio control equipment, etc.,
are accessible for checking at the same time.
•
•

CONTENTS
SAFETY INSTRUCTIONS AND
WARNINGS ABOUT YOUR O.S. ENGINE
INTRODUCTION, BASIC ENGINE PARTS
INSTALLATION
AIR CLEANER
NOTES CONCERNING THE RECOIL STARTER
GLOWPLUG
TOOLS, ACCESSORIES, etc.
CARBURETTOR CONTROLS
PRESSURIZED FUEL SYSTEM
STARTING THE ENGINE &
RUNNING-IN('Breaking-in)
FINALADJUSTMENT
CARBURETTOR CLEANLINESS
CARE AND MAINTENANCE
O.S. GENUINE PARTS &
ACCESSORIES
ENGINES EXPLODED VIEW &
PARTS LIST
CARBURETTOR EXPLODED VIEW &
PARTS LIST
THREE VIEW DRAWING
7 ~ 8
IF THE ENGINE FAILS TO START
2 ~ 517
19
20
21
17
~ 18
22
~ 27
28
~ 29
30
~ 32
8
~ 10
10
~ 11
11
~ 12
12
~ 13
13
~ 14
15
~ 16
14
6
1

Remember that your engine is not a "toy", but a highly efficient internal-
combustion machine whose power is capable of harming you, or others, if it is
misused.
As owner, you, alone, are responsible for the safe operation of your engine, so act
with discretion and care at all times.
If at some future date, your O.S. engine is acquired by another person, we would
respectfully request that these instructions are also passed on to its new owner.
SAFETY INSTRUCTIONS AND WARNINGS ABOUT YOUR O.S. ENGINE
The advice which follows applies basically to ALL MODEL ENGINES and is
grouped under two headings according to the degree of damage or danger
which might arise through misuse or neglect.
WARNINGS NOTES
These cover events which
might involve serious (in
extreme circumstances, even
fatal) injury.
These cover the many other
possibilities, generally less obvious
sources of danger, but which, under
certain circumstances, may also
cause damage or injury.
2

WARNINGS
Model engine fuel is poi-
sonous. Do not allow it to
come into contact with the
eyes or mouth. Always
store it in a clearly marked
container and out of the
reach of children.
Model engine fuel is also
highly flammable. Keep it
away from open flame,
excessive heat, sources of
sparks, or anything else
whichmightigniteit.Donot
smokeorallowanyoneelse
to smoke, near to it.
Never operate your engine in an en-
closed space. Model engines, like
automobile engines, exhaust deadly
carbon-monoxide. Run your engine
only in an open area.
Model engines generate
considerable heat. Do not
touch any part of your
engine until it has cooled.
Contact with the muffler
(silencer), cylinder head
or exhaust header pipe, in
particular, may result in a
serious burn.
••
•
•
3

This engine is intended for model cars.
Do not attempt to use it for any other
purpose.
Mount the engine in your model
securely, following the manufacturers'
recommendations, using appropriate
screws and locknuts.
Fit an effective silencer (muffler).
Frequent close exposure to a noisy
exhaust (especially in the case of the
more powerful highspeed engines)
may eventually impair your hearing
and such noise is also likely to cause
annoyance to others over a wide area.
The wearing of safety glasses is also
strongly recommended.
Take care that the glowplug clip or
battery leads do not come into contact
with rotating parts. Also check that the
linkage to the throttle arm is secure.
For their safety, keep all onlookers
(especially small children) well back
(at least 20 feet or 6 meters) when
preparing your model for running.
NOTES
•
•
•
•
•
•
4

NOTES
To stop the engine, fully retard the
throttle stick and trim lever on the
trans-mitter, or, in an emergency, cut
off the fuel supply by pinching the fuel
delivery line from the tank.
•
Warning! Immediately after a glowplug-
ignition engine has been run and is still
warm, conditions sometimes exist
whereby it is just possible for the engine
to abruptly restart if it is rotated over
compression WITHOUT the glowplug
battery being reconnected.
•
Do not attempt to disassemble the
recoil starter of the 12CV-RX.
If you do so, the very strong spring
inside will be suddenly ejected. This
can be very dangerous.
Do not extend the starter cord more
than 45cm (18"). Do not abruptly
release the operating handle. Allow
the cord to rewind smoothly while
still holding the handle.
•
•
Pull the operating handle straight out
when starting the engine, so that the
cord does not rub against the vehicle
body or engine. This will help prevent
the cord from being damaged by
abrasion or engine heat.
•
5

INSTALLING THE GLOWPLUG
Carburettor
NOTE:
With this engine, the piston will feel tught at
the top of its stroke when the engine is cold.
This is normal. The piston and cylinder are
designed to achieve a perfect running
clearance when they reach their normal
running temperatures.
Install washer on glowplug
and insert carefully into
cylinder-head, making sure
that it is not cross-threaded
before tightening firmly.
BASIC ENGINE PARTS
The MAX-12CV-R and MAX-12CV-RX are
high-perfomance engines for 1/10 class
R/Cracing cars.There aretwoverions,the
one with 10E-R carburettor and the other
with 10C carburettor. The MAX-12CV-R
has a conventional crankshaft, while the
MAX-12CV-R(P) employs a special
crankshaft with integral pilot shaft.
Crankshaft
Glow plug
Washer
Drive Hub Crankcase
Beam Mount Recoil Starter
Assembly No.5
Heatsink Heat
Starter Handle
6

ENGINE INSTALLATION
Make sure that the vehicle's engine mounting
surfaces are level and in the same plane. Poor
installation may cause distortion of the
crankcase, bearings, etc., resulting in erratic
running and loss of performance.
The recommended screws for securing the
engine are 3mm or 4-40 steel Allen hexagon
socket type.
If existing holes in the engine mount do not align
perfectly with engine mounting lugs, enlarge
them slightly with a needle-file so that screws
enter vertically.
Chassis
Chamfer inside edges of bearers.
INSTALLATION OF THE CARBURETTOR
As delivered, the engine has its carburettor
lightly fit into the intake boss. Secure it as
follows.
Loosen the retainer screw, rotate the
carburettor to its correct position and make
sure that it is pressed well down into the
intake boss, compressing the rubber gasket,
before retightening screw.
Rotate the retainer screw gently until it
stops, then tighten a further 60-90˚.
Do not overtighten the screw as this will
damage the carburettor body.
1.
2.
Rotate the retainer nut
gently until it stops. Tighten a further 60-90˚
7

NOTE:
Where spacers are supplied joined in pairs
(see sketch) separate them as shown.
Either face may be placed downwards.
Avoid forcing the screws. Secure with locknuts.
If the bottom of the recoil starter housing would
otherwise touch the car chassis, fit the engine
mount spacers (supplied) between the engine's
mounting lugs and the engine mount. Use the
M3x15 screws provided. With some vehicles, it
may be necessary to make minor trimming
modifications to chassis or body when fitting the
engine.
Mount Spacer
Engine Mount Spacer
Separate
Engine Mount
This is a heavy-duty wet type air cleaner that has
been developed specifically for the O.S. MAX-CV
series model car engines.
It contains specially impregnated filter elements which
prevent highly damaging dust and dirt from being
drawn into the engine through the carburettor, yet
allow engine performance to be maintained for longer
periods between element renewals. The Type 102 air
cleaner has a special rubber body which facilitates
easy yet secure fitting, with positive sealing at the
carburettor air intake.
AIR CLEANER TYPE 102
INSTALLATION OF AIR CLEANER
Carefully clean the carburettor,
removing any old adhesive or
sealant that may have been
previously used on the outside
of the air intake.
•
Press the air cleaner body firmly
over the carburettor air intake. Make sure that the
outer rim of the air intake engages the internal
annular groove in the air cleaner: failure to do so
may result in the air cleaner falling off. See sketch,
right.
•
8

Always remove contaminated elements carefully, to
ensure that dirt cannot enter the carburettor.
AIR CLEANER TYPE 102S
INSTALLATION OF AIR CLEANER
Carefully clean the carburettor,
removing any old adhesive or
sealant that may have been
previously used on the outside
of the air intake.
•
Press the air cleaner body firmly
over the carburettor air intake. Make sure that the
outer rim of the air intake engages the internal
annular groove in the air cleaner: failure to do so
may result in the air cleaner falling off.
•
It has a single filter element and is intended primarily
for circuit racing, where conditions are less damaging
thantheverydusty,loosesurfacesofoff-roadoperation
for which the double-element Type 101 and 102 Air
Cleaners are recommended.
The lower height of the Super Air-Cleaner 102S also
facilitates easier installation in cars where available
space may be restricted.
Position the air cleaner correctly, so that it does not
foul the cylinder-head or obstruct the needle-valve.
•
AIR CLEANER ELEMENTS
•
•
Lower Filter
Element Upper Filter
Element
Insert beneath flanges.
Replacement elements
arealreadyimpregnated
withfilteroil.Asthis oilis
very sticky, take cere,
whenhandlingelements
to prevent dust or dirt
from adhering them. If
your fingers become
contaminated, wash them with soap and water.
During storage, the oil may have become unevenly
dispersedthrough theelements. Thiswillbeindicated
ifthebluecoloroftheelementmaterialappearspatchy.
In this case, place the elements in a small plastic bag
and gently rub them between finger and thumb to
redistribute the oil.
REPLACEMENT OF ELEMENTS
It is advisable to replace the upper filter element with
a new one after not more than one hour of running
time. It is not necessary to discard the lower element
so frequently, but be sure to change it when it
becomes soiled.
•
9

Position the air cleaner correctly, so that it does not
foul the cylinder-head or obstruct the needle-valve.
INSTALLING THE FILTER ELEMENT
The element is already impregnated with a special
filter oil. As this oil is very sticky, take care, when
handling it, to prevent dust or dirt from adhering to the
element. If your fingers become contaminated, wash
them with soap and water.
During storage, the oil may
have become unevenly
dispersed through the element.
This will be indicated if the blue
colour of the element material
appears patchy. In this case,
place the element in a small
plastic bag and gently rub it
between finger and thumb to
redistribute the oil.
It is advisable to replace the filter element with a new
one after not more than one hour of running time.
Always remove contaminated elements carefully, to
ensure that dirt cannot enter the carburettor.
REPLACEMENT OF ELEMENT
Insert beneath flange
•
•
•
•
◆
◆
◆
NOTES CONCERNING THE RECOIL STARTER
( 12CV-RX ONLY)
REMINDER!
◆
◆
Do not attempt to disassemble the recoil
starter. If you do so, the very strong
spring inside will be suddenly ejected.
This can be very dangerous.
Do not extend the starter cord more than
45cm(18"). Do not abruptly release the
operating handle. Allow the cord to rewind
smoothly while still holding the handle.
Pull the operating handle straight out
when starting the engine, so that the cord
does not rub against the vehicle body or
engine.
This will help prevent the cord from being
damaged by abrasion or engine heat.
Try to avoid spilling fuel over the starter
unit and its cord. Some fuels have a
detrimental effect on these parts.
10

Glowplug life
Particularly in the case of very high performance
engines,
glowplugs must be regarded as expendable
Install a plug suitable for the engine.
Use fuel containing a moderate percentage of
nitromethane unless more is essential for racing
events.
Do not run the engine too lean and do not leave the
battery connected while adjusting the needle.
However, plug life can be extended and engine
performance maintained by careful use, i.e.:
•
•
•
GLOWPLUG
The role of the glowplug
With a glowplug engine, ignition is initiated by the
application of a 1.5-volt power source. When the
battery is disconnected, the heat retained within the
combustion chamber remains sufficient to keep the
plug filament glowing, thereby continuing to keep the
engine running. Ignition timing is 'automatic' : under
reduced load, allowing higher rpm, the plug becomes
hotter and, appropriately, fires the fuel/air charge
earlier; conversely, at reduced rpm, the plug become
cooler and ignition is retarded.
Since the compatibility of glowplug and fuel may have
a marked effect on performance and reliability, it may
be worthwhile to choose the R/C type plug found
most suitable after tests.Recommended O.S. plugs
are No.8, A5 and A3. Carefully fit plug finger-tight,
before final tightening with the correct size plug
wrench.
The starter prevents the engine from being
rotated in the wrong direction.The unit will
be damaged if you attempt to force the fly-
wheel in the opposite direction (i.e. clock-
wisewhen viewed fromthecrankshaft end).
NOTE:
Because, in the interests of personal safety,
dismantling of the starter mechanism is
strongly discouraged, the Recoil Starter is
available for replacement only as a pre-
assembled unit.
However, some related parts, such as
Starting Shaft and Rear Adaptor, are
obtainable separately. (See Parts List.)
◆
11

TOOLS, ACCESSORIES, etc.
The following items are necessary for operating the
engine.
FUEL
Use only top quality methanol-based model engine
fuel.For consistent performance and long engine life,
it is advisable to use fuel containing AT LEAST 18%
lubricant.Thisengineisdesignedtorunonbothlowand
high nitromethane content fuels,i.e. from mild mixtures
containing a few percent of nitromethane, up to high-
speed racing fuels containing 40%,nitromethane.
Generally, power output is increased
- up to a certain
point - asthenitromethanecontentofthefuelisincreased.
Apart from when actually burned out, a plug may
need to be replaced because it no longer delivers its
best performance, such as when:
When to replace the glowplug
Filament surface has roughened and turned white.
Filament coil has become distorted.
Foreign matter has adhered to filament or plug
body has corroded.
Engine tends to cut out when idling.
Starting qualities deteriorate.
•
•
•
•
•
As a starting point, we recommend a fuel containing
10-20% nitromethane, changing to a fuel containing
more nitro only if necessary. When the nitro content of
the fuel is increased or the brand of fuel is changed, it
is advisable to initially run the engine with a richer
needle-valve setting, so that the optimum setting for
the new fuel may be rechecked as described in the
RUNNING-IN paragraphs. When engines are run at
very high speeds and on high-nitro fuels, glowplug
elements do not last so long.
Model engine fuel is poisonous. Do not
allow it to come into contact with the eyes or
mouth. Always store it in a clearly marked
container and out of the reach of children.
Model engine fuel is also highly flammable.
Keepitawayfromopenflame,excessiveheat,
sources of sparks, or anything else which
might ignite it.
Reminder!
ELECTRIC STARTER AND STARTER BATTERY
Use a 12-volt electric starter
with suitable battery for start-
ing the engine.(12CV-R/R(P))
12

BATTERY INTEGRATED GLOWPLUG HEATER
Commercialy available handy
glowplug heater in which the
glowplug battery and battery
leads are integrated.
LONG SOCKET WRENCH
Recommendedfor easyremoval
and replacement of the angled
and recessed glowplug, the
O.S.Long Socket Wrench
incorporates a special grip.
SILICONE FUEL LINE
Heatproof silicone tubing of
approx. 5mm o.d. and 2mm i.d.
is required for the connection
between the fuel tank and
engine.
FUEL PUMP
For filling the fuel tank, a simple,
polyethylene "squeeze" bottle,
with a suitable spout, is required.
CARBURETTOR CONTROLS (10C)
The Needle-Valve:
The Mixture Control Screw:
The Throttle Stop Screw:
For setting the minimum idling speed.
Needle Valve
Mixture Control Valve
Assembly Screw
Throttle Stop Screw
Ball Link
NOTE:
Readjustment may
be necessary, occa-
sionally to allow for
changes in fuel for-
mula, gear ratio or
clutch engagement
point.
Three adjustable controls are provided on this
carburettor.
For adjusting the mixture strength when the throttle
is fully open.
For adjusting the mixture strength at part-
throttle and idling speeds, to obtain steady
idling and smooth acceleration to mid speeds.
13
•
•
•

CARBURETTOR CONTROLS (10E-R)
The Needle-Valve:
The Mixture Control Screw:
The Throttle Stop Screw:
Three adjustable controls are provided on this
carburettor.
For adjusting the mixture strength when the throttle
is fully open.
For adjusting the mixture strength at part-
throttle and idling speeds, to obtain steady
idling and smooth acceleration to mid speeds.
NOTE:
Readjustment may
be necessary, occa-
sionally to allow for
changes in fuel, gear
ratio or clutch en-
gagement point.
Needle Valve
Mixture Control Valve
Assembly Screw
Throttle
Stop Screw
The somewhat violent changes of vehicle attitude
that occur in off-road running, combined with the
fact that, in buggy type cars, the fuel tank is often
located some distance from the carburettor, means
that fuel 'head' at the carburettor can vary and upset
running.Therefore,it is recommended that a muffler
pressurized fuel feed system be used.
Never run your vehicle without installing the air
cleaner. Dust and dirt that may otherwise be drawn
into the engine will rapidly shorten its life.
PRESSURIZED FUEL SYSTEM
•
•
Silencer
Fuel Tank
Silicone tubing
Connect suitable length of
Silicone tubing between fuel
tank and silencer.
For setting the minimum idling speed:
14
•
•
•

approx 1mm
approx 0.3-0.5mm
The following procedure is suitable for these engines
when the O.S. T-1020 tuned silencer and a fuel
containing up to 30% nitromethane are used.
Use the same fuel as is to be employed for all initial
running and containing NOT LESS THAN 18%
lubricant.
Temporarily remove the glowplug to check that it
glows bright red when energized.
Open the Needle-Valve 2 turns from the fully closed
position.
Switch on the transmitter and
receiver and set the throttle
very slightly open from the
idling position.
DO NOT energize glowplug,
but apply electric starter to
draw fuel to carburettor.
Now connect glowplug battery
lead to heat the plug filament
and start the engine.
Re-check the needle-valve
and throttle settings. Turn
the needle-valve clockwise
slowly and gently until it
stops. This is the fully
closed position.Do not use
force to turn the needle-valve beyond this point.
•
•
•
•
Open
Close
Needle Valve
◆In case of the 10C caburettor
•
◆
In case of the 10E-R caburettor
Set the throttle-stop screw so
that the minimum throttle
opening (idle setting) is
approximately 1.0mm.
•
Throttle Stop Screw
•
Rotating
Direction
Front
Rear
•
STARTING THE ENGINE & RUNNING-IN ('Breaking-in')
Starter Handle
Push the choke button on
the fuel tank several times
to deliver the fuel to the
carburetor. (Do not over-
prime or the recoil starter
cannot be pulled.)
Pull the starter handle
briskly straight out several
times to start the engine.
•
•
In case of the 12CV-RX
15
■

30˚
Whentheenginestarts,firstallowittooperateinshort
runsonitsveryrichstartingsettings,withtheglowplug
batterystillconnectedandwithitsdrivingwheelsclear
of the ground. The rich mixture will, under these
conditions,provideadequatelubrication andcooling,
indicated by profuse smoke from the exhaust.
Next, disconnect the glowplug battery and try
running the car on the track. If the engine stalls,
open the throttle fractionally, but try to keep the
engine running as rich as possible: if it stops
because of being excessively over-rich, close the
Needle-Valve 30˚ and try again.
Runthecaronthetrackuntilonetankoffuelhasbeen
consumed, then close the Needle-Valve 30˚ and run
the car for another full tank of fuel.
Repeat this procedure until 5 more tanks of fuel have
been consumed, during which time the throttle may
Needle
The position of the needle-valve
when starting the engine.
Close the needle-valve approx.
30˚ after running the vehicle for
one full tank of fuel.
Repeat this procedure several
times.
•
•
•
30˚
30˚
To stop the engine, close the throttle to idling speed,
then shut it off completely with the trim lever on the
transmitter. To cut off the fuel supply, pinch the fuel
delivery tube to the carburettor.
•
If the engine should need to be disassembled (e.g. for
cleaning or minor parts replacement) it is advisable to
return the Needle-Valve to the original rich, starting
setting and check whether further running-in time is
required before the car is raced again. In the event of
any major working parts(e,g, piston/cylinder liner
assembly) being replaced, the complete running-in
should be repeated.
Remember!
It is vitally important to set the
throttle at the correct position
before attempting to start the
engine. If the engine is allowed to
run with the throttle too far open
under "no load" conditions, it will
rapidly overheat and may be seriously damaged.
Remember!
be opened for brief bursts of increased power. If the
engine stops at medium speeds, close the Mixture
Screw 45-90˚.
16

IF THE ENGINE FAILS TO START
Check the following:
Glowplug battery discharged or glowplug defunct.
Fuel not reaching carburettor.
Engine flooded. Do not over-prime. (This could also
cause hydraulic lock and damage the engine on
application of the electric starter.)
Remove glowplug, close needle-valve and apply
starter to pump out surplus fuel. At this time cover
the plug hole with waste so that splashing fuel will
not get into your eyes or mouth.
•
•
•
Run the vehicle (with throttle fully open) over the
longest available straight course, in order to observe
the model's speed. Next return the car to the starting
point, close the Needle-Valve 30˚ and repeat the
run, taking note of the improvement in performance.
Continue with further runs, gradually reducing the
Needle-Valve setting and aiming to achieve the
highest straight-line speed. Remember, however,
that, if the Needle-Valve is shut down too far, the
engine will overheat and, accompanied by visibly
diminished exhaust smoke, the model will lose
speed. At this point, throttle down immediately, stop
the vehicle and reopen the Needle-Valve 30˚.
With the engine running, close the throttle and allow
it to idle for about five seconds, then reopen the
throttle fully. If, at this point, the engine puffs out an
excessive amount of smoke and the vehicle does
not accelerate smoothly and rapidly, it is probable
that the idling mixture is too rich.
FINAL ADJUSTMENT
•
•
•
12CV-R/R(P) 12CV-RX
Having established the optimum Needle-Valve
setting, check the Mixture Control Valve setting as
follows.
17

In this case, turn the Mixture Control Valve
clockwise 45~90˚. If, on the other hand, the engine
tends to speed up momentarily and then cut out
abruptly when the throttle is opened,the idling
mixture is too lean. Correct this by turning the
Mixture Control Valve counter-clockwise 45~90˚.
Warning!
NOTE:
Mixture Control Valve adjustment should be made
in steps of not more than 45~90˚, carefully
checking the effect,on throttle response, of each
small adjustment.
Carry out adjustments patiently, under actual
running conditions, until the engine responds
quickly and positively to the throttle control.
Mixture adjustments (whether via the Mixture
Control Valve, or the Needle-Valve) cannot be
made accurately under 'no-load' conditions,
which, in any case, are not advised, since such
operation carries the risk of seriously damaging
the engine through over-revving and overheating.
•
•
With the optimum mixture control position, light
smoke is visible during high speed running,and the
engine revolutions increase smoothly during
acceleration. Remember that, if the engine is
operated with the fuel/air mixture slightly too lean, it
will overheat and run unevenly. As with all engines,
it is advisable to set both needle-valve and mixture
control screw very slightly on the rich side of the best
rpm setting, as a safety measure.
If the engine runs too fast with the throttle closed,
the throttle stop screw should be turned counter-
clockwise to allow the throttle opening to be
reduced.
•
•
•
Finally, beyond the nominal break-in period, a slight
readjustment toward a leaner needle setting may be
required to maintain performance.
18

BALL LINK AND SLIDE VALVE EXTENSION
It is seldom necessary to separate the slide-valve
extension from the slide-valve itself. For cleaning,
withdraw this complete sub-assembly from the
carburettor body after removing the slide-valve guide
screw. Then wash with methanol or glow-fuel.
(Note: take care not to lose the guide screw;it is a
special one.) When it is necessary to adjust the ball-
link position, loosen the ball-link retaining screw with
a 2.5mm hexagon key, re-align the ball-link and re-
tughten the screw firmly.
(In case of the 10C caburettor)
REALIGNMENT OF MIXTURE CONTROL VALVE
■
In the course of making carburettor adjustments, it is
just possible that the Mixture Control Valve may be
inadvertently screwed in or out too far and thereby
moved beyond its effective adjustment range.Its basic
position can be found by first rotating the Mixture
Control Valve until its slotted head is flush with the
carburettor body. The valve is then screwed in exactly
2.5 turn to re-establish its neutral position.
Mixture Control Valve
Carburettor Body
First rotate the Mixture Control
Valve until its slotted head is
flush with the carburettor body.
Then screw the valve in exactly
2.5 turn.
This is the standard position.
■In case of the 10C caburettor
In case of the 10E-R caburettor
Carburettor Body
Mixture Control Valve
First rotate the Mixture Control
Valve until its slotted head is
flush with the carburettor body.
Then screw the valve in
exactly 0.5 turn.
This is the standard position.
Throttle Lever
CARBURETTOR CLEANLINESS
The correct functioning of the carburettor depends on its small fuel orifices remaining clear.
19