Service manual

ManualsBrandsSCORPION ManualsSnowmobiles1975 Brut

SERVICE

MANUAL

-

1975

SCORPION

BRUT

FUNCTIONAL

DESCRIPTION:

GENERAL

The

purposes

of

the

carburetor

are:

( 1)

to

break

fu

e l

int

o

tiny

partic

l

es

(vaporize)

(2)

to

mix

the

fuel

with

air

in

the

proper

ratio

and

(3)

to

deliver

the

combustible

mixture

to

the

engine.

Pulsations

from

the

crankcase

through

the

impul

se

tube

ac

tuat

e

th

e

fuel

pump

diaphragm

to

transport

fuel

from

the

tank

into

the

carburetor

.

As

engine

fuel

demand

increases

,

differential

pressure

f

orces

fuel

from

the

carburetor

float

bowl

through

app

li

cab

le

orifices,

je

t s a

nd

passages

into

the

main

bore

and

from

the

bore

into

the

engine.

The

floats

actuate

the

car

b u

retor

needle

valve

to

maintain

an

adequate

fuel

supply

in

the

bowl

for

all

eng

ine

demands.

In

order

for

the

carburetor

to

provide

the

correct

air/fuel

ratio

under

all

eng

i

ne

loads,

four

sepa

rat

e

fluid

circui

ts

are

provided:

(1)

Starter

Syst

em

(2)

Pilot

System

(3)

Main

System

(4)

Float

System

The

schematics

included

in

the

section

are

functionally

correct

but

do

not

necessar

ily

represent

the

actua

l

physical

appearance

of

the

carburetor

. A

signif

i

cant

departure

from

the

physical

arrangement

occurs

in

connection

with

the

main

jet

.

The

schemat

ic

indicates

the

main

jet

to

be

attached

to

the

lower

end

of

the

need

le je

t.

On

the

Mikuni

carburetor

used

on

the

Brut,

the

main

jet

is

l

ocated

in

the

main

jet

holder

(See

FIG

. 2-

12).

but

it

st

ill

performs

the

same

function.

On

this

carburetor,

the

fitting

on

the

l

ower

end

of

the

needle

jet

serves

to

hold

the

nee

dle

jet

in

position.

It

is

bored

out

l

arger

than

the

main

jet

so

that

it

does

not

restrict

the

fluid

f lo

w.

2-2

)