O.S. engine MAX-21VZ-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.

●

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.

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 an 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.

••

•

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.

Install 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

•

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.

•

BASIC ENGINE PARTS

With this engine, the piston will feel tight 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.

Heatsink Head

Carburetor

Type 20K

Crankshaft

Crankcase

Mounting Lugs

Exhaust

As delivered, the engine has its carburetor lightly

fit into its intake. Secure it changing its angle

according to the car chassis.

NOTE

Standard accessories

Glow Plug P7 Cylinder-head gasket (0.1mm)

Exhaust Seal Ring Dust Cap 3, 16, 18

The MAX-21VZ-R is high performance 3.5cc

class power unit for one-eighth-scale radio-

controlled 'Track racing' cars. It has been de-

signed to meet the exacting requirements of

the world's most expert drivers. An exhaustive

program of research, development and proto-

type testing has resulted in one of the most

powerful production model racing car engines

currently available.

NOTE

The engine is fitted with one each of 0.1mm and

0.2mm cylinder-head gasket when leaves the

factory. Another 0.1mm head gasket is supplied

with the engine. You may addit at initial running-

in, when a glow plug tends to burn out due to high

temperature and / or high humidity or when you

prefer fuel economy to power.

Cover Plate

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

themslightlywithaneedle-filesothatscrewsare

in alignment with the mounting holes.

Chassis

Chamfer inside edges of bearers.

INSTALLATION OF THE CARBURETOR

Asdelivered,theenginehasitscarburetorlightly

install into its intake boss. Secure it as follows.

Loosen the retainer screw, rotate the

carburetor to its correct position and make

sure that it is pressed well down into the

intake boss, compressing the rubber gasket,

before retightening screw.

2. Rotate the

retainer nut

gently until

it stops.

Tighten a

further

120-180˚

Rotate the retainer

screw gently until it

stops, then tighten

a further 120-180˚.

Do not overtighten

the screw as this

will damage the

carburetor body.

2. Install the exhaust seal ring supplied.

Insert carefully into heatsink head, making

sure that it is not cross-threaded before

tightening firmly.

Do not allow bottom

of crankcase to

touch chassis.

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 P7. Carefully install plug finger-tight, before final

tightening with the correct size plug wrench.

GLOWPLUG

The role of the glowplug

Glowplug life

Particularly in the case of very high performance

engines,

glowplugs must be regarded as expendable

items. However, plug life can be extended and engine

performance maintained by careful use, i.e.:

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.

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.

•

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.

•

TOOLS, ACCESSORIES, etc.

FUEL

Generally, it is suggested that the user selects a fuel

that is commercially available for model two-stroke

engines and contains 10-30% nitromethane. As a

starting point, we recommend a fuel containing 20%

nitromethane, changing to a fuel containing more nitro if

necessary. When the brand of fuel is changed, or the

nitro content increased, it is advisable to repeat the

running-in procedure referred to in the RUNNING-IN

paragraphs.

The following items are necessary for operating the

engine.

REMINDER!

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. Keep it away from open flame,

excessive heat, sources of sparks, or

anything else which might ignite it. Do not

smoke or allow anyone else to smoke,

near to it.

Please note that with high-nitro fuels, although power

may be increased for competition purposes, glowplug

elements do not last so long and engine life will be

shortened.

BATTERY INTEGRATED GLOWPLUG HEATER

Commercialy available handy

glowplug heater in which the

glowplug battery and battery

leads are integrated.

FUEL PUMP

For filling the fuel tank, a simple,

polyethylene "squeeze" bottle,

with a suitable spout, is required.

STARTER BOX

For starting the engine.

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.

CARBURETOR CONTROLS

The Needle-Valve:

•

The Mixture Control Screw:

•

The Throttle Stop Screw:

For setting the minimum idling speed:

•

Four 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.

Needle Valve

Mixture Control Valve

Assembly Screw

Throttle Stop Screw

NOTE: Readjustment may be necessary,

occasionally to allow for changes in fuel formula

gear ratio or clutch engagement point.

The Metering Needle:

•

Metering Needle

For changing the feeling at mid speads and

acceleration. (Do not rotate the screw more chan

one turn.)

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