Harley Davidson MX 250 1978 Owner's manual

1978

Owner's

Manual

MX

25O

COMPETITION

MODEL

IMPORTANT

NOTICE

The MX-250

Inc. without

factured

federal

public

Some

streets,

state laws

Model warranty.

for

competition

motor

roads

vehicle

prohibit

an organized racing

course which

ed

sanctioning

governmental

For

off-road

additional

Such

spark

with

noise

Performance

n

ecessa ry

This motorcycle

model.

only

permit

cycle, first

For

owner's

carrying

_safe

is conducted urider

body or

authority having

use

other than

spark

arrester-muffler may

arresters

level

and spark

wilt

.

is

The vehicle

passenger.

a

determine

operation

manual

HARLEY-DAVIDSON

carefully.

is sold by Harley-Davidson

This vehicle

use

only. lt

safety

highways

or

operation

or competitive

by

is designed

does not

standards

is illegal.

of this vehicle

event

the

auspices of

permit

issued

and operation

jurisdiction.

sanctioned

are available

arrester

be decreased

designed

that operation

and

and constructed

load limit

Before

proper

MOTOR

commercially

and

maintenance,

racing

required

be

laws

and regulations.

retuning

and seat operating

legal.

is

CO., INC.

Motor

and manu-

conform

except

upon

recogniz-

a

by

the local

events,

to comply

as

an operator

do not

your

read

Co.,

on

a closed

an

by law.

may

be

safely

motor-

the

to

in

YOUR

OWNER'S

MANUAL

Welcome

designed pared

to the Harley-Davidson

and manufactured provide

to

the instructions

Your

owner's

Harley-Davidson

properly

maintain

to be

a simple

carefully

manual

dealer

this vehicle.

TECHNICAL

OPE RATI

I

NSPECTION

MAINTENANCE TROUBLESHOOTING MAINTENANCE SERVICE

and understandable guide

for its

contains

has

instructions

facilities,

the

DATA

NG INSTRUCTIONS

AND

SPECI FICATIONS

Motorcycling

finest

the

maximum

in

performance

experience

TABLE

Section

ADJUSTMENTS

SCHEDULE

Familyl

its field.

for

owner

OF CONTENTS

for

and

Your

The

your

and

care,

genuine

new

Harley-Davidson

instructions

motorcycle's

your

personal

maintenance

Harley-Davidson

in

this book

operation

motorcycling

and minor

Page

2

7

I

16

24 25 26

Motorcycle

have

and care.

repair.

parts

necessary

Motor

pre-

been

Follow

pleasure.

your

Co,, Inc.

is

to

A complete

alphabetical

index

appears

at the

end

of

this manual

WEIGHT

DIMENSIONS

Overall

Handlebar width

Ground

length

clearance

Wheelbase

Dry weight

AND

. . .

.....57.3in.(145.5cm)

Steeringangle.

Rake.

Trail .

Telescopic

Front suspension

Rear suspension

Fuel tank

Transmission

fork .

Frorrt

Model designationletter.

. . .

. .

8.9

. . . Swinging arm,

CAPACITIES

2.2

. . 7 oz.

ENGINE

(wet)

.2112

(212.5

in.

83.6

34.2in.

12

in.

233 lbs.

in.

. 5.5

oil dampened

(225

in.

mm)

oil dampened

US Gallons

pts.

each side

cm)

(87

cm)

(30.5

cm)

(105

Kg)

....45'

... . 30'

(140

mm)

travel

coil spring

(8.5

lt)

No reserve

(1200

(210

..

cc) cc)

MX

Type .

Bore .

Stroke

Piston

displacement

. . . .

Compressionratio

Fuel and

Lubrication

system

. . . .

Startersystem

IGNITION

Type . .

lgnition

Triggbr air

Spark Spark

Capacitor

timing

plug

gap

.

electrode

Discharge

. . . .

gap

CARBURETOR

Type.

Venturi dia . .

Mainjet

Lowspeedjet....

cycle,

2

2.835

2.346

..

3.590

Primarykickstarter

...

SYSTEM

DANSI or

(Dansi)

0.020 in.

.. Dell'Orto

..

single cYlinder

in.

(59.6

in.

1242.6

....11.8:1

mixture

oil

Motoplat

CDI

before

-

0.012

(0.40

-

0.50

(

PHM3SGS

1.496 in.

....189

....,..70

(72

mm) mm)

ccl

: 1

2O

TDC

0.016 in.

mm)

0'5

(38

mm)

2

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Starting

Throttleslide

jet

...

.............

:..

Meteringpin..

Mainnozzle ....

f dfe mixture

screw setting .

Air filter Plastic

1

.....75

....K2

...260A8

1/2 turns

foam

element

open

Gearshiftpattern

Transmission Chain

type

sprocket

.

518

114

x

Harley-Davidson

Part

down

-4up

l

No.40000-77.M

TRANSMISSION

Clutch wet, multi Primary drive Primary Primary

Gear ratios:

drive

ratio .

Firstgear

Second

Third

Fourth

gear

gear.

gear

pinion clutch

gear

... :.....(1:1.928)...

.

,i. . . . . . .(1

.{. .r.

'i

..

SYSTEM

. ..:22teeth

..i...

..60teeth

....(1:1.555)...

:1.238)

(t

:1

.;

. )

. . .

.

Fifthgear.....

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plate

2.727

14127

18/28

2't/26

21/21 23119

Frontwheel

Rear

wheel

Front

brake . . .

Rear

brake

Rims.

Spokes

pressure.

Tire

WHEELS

AND BRAKES

tire..

.

tire .

. internal expanding,

(0.i

psi

.. 10

....3.00x21

single

shoe type,

shoe type, i.d.

36/wheel,4

Kg/cm2

i.d. 140

)front

in.

leading

mm

140 mm

mm

dia.

and

rear

Throttle control

1.

Front brake

2.

Rear

3.

4.

brake

Kickstarter lever

control

pedal

grip

lever

-

Fig. 1

Right

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side view

1.

Gearshift

2.

Clutch leyer

3.

Fuel valve

4.

Fuel

tank

lever

filler

cap

Fig. 2

-

Left

side

view

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5_

Running in the

MX 250

The

Operate the

more

than

engine

This

without high

practice

erly. The

Motorcycle

requires a short breaking

motorcycle for

half

throttle.

RPM

will help

running-in should be

moving

the

Maintain light load or lugging.

parts

first hour using not

to break-in

performed

with new motorcycles, but also after

cylinder,

Fuel

The MX 250

gasoline-oil

a

correct

engine

Use

20

engine.

Use only

gasoline.

piston

and oil

oilquality and

damage.

high

a

:

1 is the coqrect

Premium Grade

,

andlor

recommendation

has a two-stroke

mixture

quality

piston

for

mixture ratio in order to avoid

SAE 30

gas

rings.

engine which requires

proper

lubrication. Use the

viscosity racing oil.

mixture ratio

to oil

(high

octane) leaded

period.

in

on the

prop-

not only

replacing

for

this

much

excessive

preignition.

Fuel

-

Always

Pour

and

sure the fuel

Do not

Remember

easily with

Use the oil-gas mixture within

oil

will cause spark

carbon

mixing

procedure

mix

the oil

shake thoroughly for

that the

tank.

mix vegetable

formation

gasoline

and the

fuel

is

and gasoline

properly

and mineral oils.

that vegetable oils

gasoline

mineral oils

as

oil in

a

plug

that

a clean

fouling

may lead

and

container.

into the container

few

minutes.

mixed, before

not mix

do

do.

few

a

filling

days.

to

Make

as

Too little

engine wear

oil

in

the mixture

possible

and

will cause

engine

severe

damage. Too

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Transmission

premium

Use

a

engine

oil.

oil

quality

SAE

\0

W

-

40

or 20 W

-

50

Starting

-

When enrichment starter

grip.

starts.

when

-

When

mixture

throttle

starter

the engine

lever

sharply

Open the

Lower

the engine

the

the fuel

engine

enrichment

114

of

lever.

is

cold, raise

(A

-

fig.

without

throttle

mixture

warms

up.

is warm,

lever

a turn

the fuel

3). Push

valve

down

opening

when

enrichment

do

not

use

(fig.

4l'.

and operate

mixture

the kick-

the

throttle

the engine

lever

the fuel

Open

the

the kick

Fig.

-

3

Fuel

mixture

-

4

Fuel

mixture

enrichment

lever

-

OFF

ON

(open)

(closed)

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