Page 1
-KOHLER
ENGINES
4-CYCLE
•
SHORT-STROKE
•
AIR-COOLED
M 0 D
E
L
1.8
H.P.
at
1800
R.P.M.
K91RT
2.6
H.P.
at
2400
R.P.M.
3.S
H.P.
at
3200
R.P.M.
SPEC.
NO.
31600-A
3.8
H.P.
at
3600
R.P.M.
f
AS
MANUFACTURED FOR
4.0
H.P.
at
4000
R.P.M.
.!
THE
ESKA
COMPANY
Kohler
engines
are
manufactured
under
the
close
super-
visionofskilled
technicians.
The
engines
are
precision
units,
machined
and
assembled
to
deliver
many
hours
of
reliable
service.
All
components
are
produced
under
rigid
inspection,
tested
under
load
conditions,
and
adjusted
to
meet
exact
specifications
before
shipment
is
made.
Kohler
engines
are
solidly
constructed
withaheavy
duty
cast
iron
block,
employing
modern
short
stroke
design,
and
built-in
mechanical
governor.
This
folder
will
assist
you
by
offering
the
correct
procedures
for
care
of
Kohler
engines.
For
a
K91
engine
service
manual
with
complete
operation,
main-
tenance,
overhaul,
and
parts
identification
information,
send
$1.50
to:
Engine
Service
Department
Kohler
Co.,
Kohler,
Wisconsin
OPERATING INSTRUCTIONS
1.
Before
Starting
a.
Remove
oil filler
cap
and
check
oil level.
Add
clean
oil
to
mark
indicated
on
dipstick
(SAE
5W-20).
Oil
should
not
be
over
full
mark.
b.
Keep
fuel
tank
filled
with
clean,
fresh
gasoline
of
regular
grade
to
prevent
condensation
in
cold
weather.
DO
NOT
MIX
OIL
WITH
GAS-
OLINE.
Be
sure
fuel
tank
cap
vent
hole
is
open.
Vent
hole
can
freeze
over
while
plowing.
c.
Remove
both
plugs
of
reduction
gear
unit
and
add
oil,
(same
grade
as
used
in
crankcase)
to
oil level hole.
Be
sure
that
vent
holeofoil fill
plugisopen.
If
oil
bubbles
outofvent
hole
of
oil fill
plug,
thereistoo
much
oil.
d.
Break
rotor
blade
free
before
starting.
2.
To
Start
a.
Open
valve
on
sediment
bowl.
b.
Close
choke
lever.
Choking
may
be
necessary
due
to
variations
in
temperature,
grade
of
fuel,
etc.
Littleorno
choking
willbenecessary
when
engineiswarm.
Experience
will
teach
you
the
degree
necessary
under
varying
conditions.
Open
remote
throttle
about
half
way
until
engine
starts,
then
set
at
desired
speed.
Extreme
Cold
Idle
screwissetatfactory
for
fast
idle.
Close
throttle
and
setatfull
choke.
When
engine
has
started,
open
choke
slowly,
making
adjustments
1
as
engine
warms
up.
Use
Autolite
AR8
spark
plugorequivalent.
Below
_25
0
F.
Apply
heattoengine
cylinder
head,
spark
plug,
and
oil
pan.
Engine
will
startat- 400F.
with
heat
application.
c.
Give
starter
pulley
quick,
steady
pull.
Do
not
jerk
or
pull
retractable
starter
to
end
of
cable
-return
handle
slowly.
DO
NOT
ALLOW
HANDLE
TO
SNAP
BACK.
d.
Slowly
return
choke
to
open
position
as
engine
warms
up.
3.
To
Stop
Whenever
possible,
allow
engine
to
idle,
with
no
load,
before
stopping.
a.
Press
red
breaker
point
"STOP"
button
and
hold
until
engine
is
completely
stopped.
b.
See
Instructions
for
Storing
if
engine
is
to
be
taken
outofservice
for a
considerable
length
of
time.
4.
Precautions
Stop
engine
before
filling fuel
tank.
Avoid
spilling
gasoline
onahot
engine.
Always
use
fresh,
clean
gasoline.
a.
Avoid
lnJuries.
Always
disconnect
spark
plug
cable
before
making
any
adjustment
to
machine
powered
by
engine.
Cont.onpage
4
BrentChalmers.com
Page 2
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130--~L
I!'
125
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117
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118
123
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II
6-
113
o
121
54
29
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97
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BrentChalmers.com
Page 3
ESKA
MODEL K91RT
-
SPEC.
NO.
31600-A
PARTS
LIST
Item I
Quan-I
Part
I·
Item
Quan-
Part
Item
Quan-
Part
No.
tity
No.
Description
No.
tity
No.
Description
No.
tity
No.
Description
----------
--
--
--
--
46
1
220541
Head,
cylinder
99
1
220132
Bushing,
governor
AIR INTAKE
GROUP
100 1
220156
Bracket,
speed
con'trol
1 2
X-18-2
Washer,
lock
DIPSTICK
GROUP
101
1
220380
Linkage,
governor
2 2
X-51-43
Screw,
R.H.M.
8-32xYs
48
I
1
I
A-220092
I
Dipstick-assembly
97
1
220873
Disc,regulating
50
1
220854
Cover,
duct
51
1
220855
Body,
duct
EXHAUST
GROUP
IGNITION
GROUP
3
1
235308
Element
2
X-81-1
Nut,
hex.
7.4:-20
4
1
220537
Gasket
54
1
220122
Gasket,
muffler
1
X-5-1
Screw,
H.C.
7.4:-20x%
55 2
220133
Stud,
muffler
104
1
X-20-1
Washer,
lock
7.4:
BAFFLES &
SHROUD
GROUP
1
X-22-18
Washer,
lock8I.E.T.
5 2
X-132-1
Screw,
H.C.
>i-20xYs
56
1
A-220145
Muffler-assembly
1
X-25-48
Washer
8
6
4
X-132-5
Screw,
H.C.
>i-20x%
FLYWHEEL
GROUP
1
X-25-63
Washer
>i
8
1
220049
Baffle,
head
Washer,
lock
Vt6
105 2
X-67-22
Screw,
self
tapping
10
9
1
220054
Baffle,
cylinder
60 1
X-23-1
102
1
X-67-37
Screw,
self
tapping
10 1
220220
Housing,
blower
61 1
X-43-3
Key,
woodruff
5
8-32x%
62 1
X-88-2
Nut,
hex.
Vt6-2O
103 4
X-131-1
Screw,
F.H.M.
10-24xYs
BREATHER
& VENT
GROUP
63
1
A-220636
Flywheel-assembly
(w/washer)
11 1
X-20-1
Washer,
lock
7,{
106
1
X-489-1
Rod,
breaker
12
1
X-81-1
Nut,
hex.
7,{-20
FUEL
TANK&FITTINGS
GROUP
107
1
A-220136
Cover,
breaker-assy.
13 1
210256
Filter
64
2
X-5-7
Screw,
H.C.
>i-20x1
108 1
220174
Gasket
14
1
220357
Plate,
breather
65
2
X-101-8
Nut,
stop
>i-20
109
1
A-220409
Stator-assembly
15 1
220358
Cover,
valve
66 1
X-217-6
Nipple
115
1
220435
Coil
16 1
220368
Stud,
cover
67
1
210101-A
Filter,
fuel-assenbly
116 1
220434
Condenser
17 1
220369
Seal,
breather
68
1
220097
Line,
fuel
110
1
A-220443
Cable,
hi-tension
18 2
220370
Gasket,
cover
71
2
220154
Strap,
tank
111
1
A-220474
Breaker-assembly
19
1
220379
Reed,
breather
72
1
220158
Bracket,
tank-L.H.
112 1
A-220512
Lead,
breaker
74
2
220166
Webbing
1
220856
Spring,
stop
control
CAMSHAFT & VALVES
GROUP
73
1
220514
Bracket,
tank-R.H.
1
220857
Bracket,
stop
control
20
1
220008
Valve,
intake
1
220547
Sleeve
113 1
240667
Plug,
spark
21
1
220009
Valve,
exhaust
1
220786
Nut
114
1
275183
Clip,
cable
22 2
220010
Spring,
valve
70 1
A-220852
Tank,
fuel-assembly
23 2 220011
Retainer,
spring
1
220853
Cap,
tank
NAMEPLATE
GROUP
24
2
220013
Tappet,
valve
69
1
231510
Elhow,
compression
25
2
220052
Pin,
valve
lock
117
I
4
I
X-S13-1
Screw,
sheet
metal
26
1
220053
Pin,
camshaft
GEAR REDUCTION
GROUP
-7x3/g
27 1
A-220140
Camshaft--assembly
76
2
X-5-4
Screw,
H.C.
>i-20x1>i
118 1
220630
Nameplate
77
4
X-6-23
Screw,
H.C.
5j6-24x%
1
220673
Decal,4H.P.
CARBURETOR
GROUP
78
4
X-20-1
Washer,
lock
Yi
31
2
X-140-1
Screw.
sltd.
hd.
79
2
X-21-1
Washer,
lock
K6
OIL
PAN
GROUP
7,{-20x%
80
1
X-75-2
Plug,
pipe
)4'
120I1
I
X-75-2
I
Plug,
pipe
)4'
29 1
210223
Gasket,
carburetor
2
X-81-1
Nut,
hex.
)4'-20
122 4
X-154-1
Screw,
H.C.
%;-18xYs
32
1
E-220517
Carburetor-assembly
81
1
X-230-11
Plug,
expansion
113 1
220167
Pan,
oil
1
231324
Decal,
choke
82
1
X-271-11
Seal,
gear
cover
121
1
220775
Gasket,
pan
30
1
231510
Elbow,
compression
83
1
X-271-15
Seal,
gear
housing
28
1
220547
Sleeve
84
2
D-997
Washer,
copper
1
220786
Nut
85
1
205013
Plug,
pipe
PISTON&ROD
GROUP
86
1
220211
Housing,
gear
124 1
220467
Ring
set-std.
CRANKCASE
GROUP
87
1
220212
Cover,
gear
1
B-220070
Rod,
connecting-assy.
33
4
X-5-1
Screw,
H.C.
7.4:-20x%
88
1
220213
Gear,
drive
125 1
B220111
Connecting
rod
34
4
X-25-55
Washer,
copper
7.4:
90
2
220216
Bushing,
drive
shaft
126
1 220492
Lock,
connecting
rod
35
1
X-271-15
Seal,
front
oil
91
1
220218
Gasket,
cover
127
2
220491
Screw,
connecting
rod
36
1
X-271-16
Seal,
rear
oil
2
220790
Stud
128 1
A-220103
Piston-assy.,
std.
37
1
X-301-6
Button,
plug
89
1
220858
Shaft,
gear
129
2
220004
Retainer,
pin
38
2
200110
Bearing,
ball
Pour
engine
oil
into
gear
housingatfiller
hole
130
1
220003
Pin,
piston
39
1
220071
Gasket,
bearing
plate
until
oil
runs
from
oil
level
holeatlower
end.
40
1
220385
Plate,
bearing
RETRACTABLE
STARTER
GROUP
41 1
A-220459
Block,
cylinder-assy.
GOVERNOR
GROUP
131 4
X-19-1
Washer,
lock
10
CRANKSHAFT
GROUP
92
1
X-5-7
Screw,
H.C.
>i-20x1
4
X-25-7
Washer
10
93
2
X-25-63
Washer
7,{
132 4
X-50-2
Screw,
R.H.M.
10-32x%
42I1
I
220433ICrankshaft
1
X-67-5
Screw,
drive
133
1
C-220589
Starter,
recoil-assy.
94
1
X-81-1
Nut,
hex.
>i-20
134
1
A-220594
Cup,
drivew/screen
CYLINDER HEAD
GROUP
1
X-269-13
Ring,
snap
43I1
1220124
I
Gasket,
head
95
1
220119
Spring,
governor
44
6
220257
Screw,
H.C.
%;x18x1->i
96
1
220126
Lever,
governor
220151
Gasket
set
45
6
220S34
Washer
%;
98
1
220131
Shaft.
governor
Indented
part
numbers
and
descriptions
are
components
of
preceding
assembly.
Order
parts
from
your
nearest
Kohler
dealer
giving
part
number
and
description
of
part
and
model
number,
specification
number
and
serial
number
of
engine.
3
BrentChalmers.com
Page 4
GEAR REDUCTION
The
reduction
unit
is a
gear
type
runninginoil.
Tl,1e
drive
gearismachined
on
the
crankshaft
and
the
driven
geariskeyed
and
pressed
onto
the
power-take-off
shaft.
The
shaftissupported
by
two
bronze
bearings
located
in
the
gear
housing
and
in
the
gear
cover.
.
1.
Before
Operating
a.
Remove
oil fill
plug
and
oil level
plug
and
fill
gear
unittooil level hole.
Use
same
gradeofoil
recommended
for
engine.
b.
The
reduction
gearisvented
through
the
oil fill
plug.
This
vent
should
be
checked
dailytosee
thatitis
open.
c.
Change
reduction
gear
oil
every
100
operating
hours.
2.
To
Service
a.
Remove
four
cap
screws
from
gear
housing,
slide
off
cover
and
remove
power-take-off
with
driven
gear.
b.
Remove
four
cap
screws
that
hold
gear
hop.sing
to
engine
block.
Use
socket
wrench.
c.
Wash
all
parts
and
inspect
shaft,
bushing,
and
gears
for
wear.
Replace
all
worn
parts,'
d.
Remove
old
oil
seals
and
install'new
seals
(flat
side
out)
in
gear
housing
and-reduction
.gear
cover.
3.
Assembly
a.
'Wrap
tape
around
crankshaft
geartoprotect
oil
seal,
slide
gear
reduction
housing
over
shaft
and
attach
to
block.
Two
lock
washers
are
used
on
outside
and
copper
washers
inside.
b.
Place
thrust
washers
on
shaft,
one
on
each
side
of
reduction
gear.
c.
Tape
shouldbewrapped
around
shafttoprevent
keyway
from
damaging
oil
seal
while
cover
is
installed
on
power-take-off
shaft.
d.
Install
gaskets
on
cover
and
place
assembly
in
position
on
gear
housing.
CONTACT YOUR
NEAREST
KOHLER
DEALER
FOR REPAIR
PARTS
KOHLER
CO.
Established
1873 KOHLER,
WIS.
K
o
H
L E R
o F K o H
L
E
R
EN405
6M-7-62-Z
6
LITHO
INU.S.
A.
BrentChalmers.com
Page 5
b.
Crankcase
and
air
cleaner
must
be
properly
serviced
at
all
times.
Dirt
drawn
through
im-
properly
serviced
air
cleaner
can
ruin
an
engine
in
a few
operating
hours.
c. Allow
engine
to
warm
up
before
applying
work
load.
d.
Keep
cylinder
block,
flywheel,
cylinder
hea.
cooling
fins,
and
rotating
air
screen
free
of
ice
and
snow.
e.
Do
not
operate
at
speeds
greater
than
governor
settingorrun
continuously
under
maximum
load.
MAINTENANCE
1.
Each
Day
a.
Check
fuel
supply
and
oil level
in
crankcase.
Add
oil
only
as
needed
to
keep
level
between
marks
on
oil
gauge.
b.
Clean
oil,
dirt,
and
snow
from
external
surface
of
power
unit.
c.
Check
air
intake
and
cooling
fins
for
obstructions
and
ice.
2.
Every
2S
Operating
Hours
a.
Change
oilincrankcase.
b.
Check
gasket
joints
between
air
cleaner,
car-
buretor,
and
air
intake
manifold.
3.
Every
100
Operating
Hours
Perform
25
hour
service
and
in
addition:
a.
File
electrode
areas
and
regap
spark
plugto.025.
Use
Autolite
AR-8
plugs,orequivalent,
for
cold
weather
operation.
b.
Remove,
clean,
and
replace
sediment
bowl.
c.
Check
breaker
points
and
regap
to
.020.
d.
Oil recoil
starter
through
hole
indicated
on
starter
housing.
Use
lube
equivalent
to#5grade
oil.
4.
Instructions
for
Storing
If
engineisto
be
outofservice
for a
considerable
length
of
time,
the
following
procedure
is
recom-
mended:
a.
Drain
fuel
tank.
b.
Drain
carburetor
by
pressing
bowl
drain
button
on
bottom
of
carburetor
bowl.
c.
Remove,
clean,
and
replace
sediment
bowl.
d.
Clean
exterior
surfacesofengine.
e.
Spreadalight
filmofoil
over
any
exposed
sur-
faces
of
engine
subject
to
corrosion.
f.
Pour
tablespoonofoil
into
spark
plug
hole
and
crank
engine
slowly
by
hand.
Replace
plug.
g.
Do
not
expose
to
elements-store
in
dry
place.
TROUBLE
SHOOTING
Following
is a
listoftroubles
which
may
occur
through
average
use
and
normal
wear:
1.
Hard
Starting
a.
Faulty
Ignition
(1)
Loose
or
grounded
high
tension
on
breaker
point
leads.
(2)
Improper
breaker
point
gap.
(3)
Defective
breaker
points.
(4)
Faulty
spark
plugs.
(5)
Faulty
condenser
or
coil.
(6)
Incorrect
spark
timing.
(7)
Check
ignition
system
for
moisture.
b.
Faulty
Carburet
ion
(1)
Gasoline
not
getting
to
carburetor.
(a)
Ice,
dirt
or
gum
deposits
In fuel
line.
(2)
Dirt
in
carburetor.
(3)
Carburetor
improperly
adjusted.
c.
Compression
Loss
(1)
Valves
leaking
or
sticking.
(2)
Rings
worn.
(3)
Head
gasket
leaking.
4
2.
Overheating
a.
Insufficient
cooling
air
available.
b.
Dirtyorclogged
intake
screen,
shroudor.cooling
fins.
c.
Improper
fuel.
d.
Fuel
mixture
too
lean.
e.
Improper
ignition
timing.
3.
Backfiring
a.
Fuel
mixture
too
lean.
b.
Sticky
intake
valve.
c.
Improper
ignition
timing.
d.
Point
gap
open
too
far.
4.
Occasional
MissingatHigh
Speed
a.
Spark
plug
gap
too
wide.
b.
Improper
carburetor
adjustment
or
lackoffuel.
c.
Wrong
type
spark
plug.
d.
Improper
ignition
timing.
S.
Missing
Under
Slow,
Hard
Pull
a.
Spark
plug
gap
too
wide.
b.
Pitted
breaker
points.
BrentChalmers.com
Page 6
c.
Partially
fouled
spark
plug.
d.
Defective
ignition
timing.
6.
Knocking
a.
Fuel
octane
rating
too
low.
Useagood
grade
of
regular
gasoline.
b.
Improper
ignition
timing.
c.
Overheated
engine.
d.
Loose
connecting
rod.
e.
Excessive
carbon
In
combustion
chamber.
f.
Lack
of
lubrication.
7.
Operating
Erratically
a.
Clogged
fuel line.
b.
Waterinfuel.
c.
Faulty
choke
control.
d.
Improper
fuel
mixture.
e.
Loose
ignition
system
connection.
f.
Air
leaksinmanifold
or
carburetor
connections.
8.
Engine
Will
Not
Idle
a.
Improper
carburetor
idling
adjustment.
b.
Carburetor
jets
clogged.
c.
Spark
plug
gap
too
small.
.025.
d.
Leaking
carburetor
or
manifold
gaskets.
e.
Sticking
or
leaking
valves.
f.
Weak
coilorcondenser.
9.
Engine
Stops
While
In
Operation
a.
Check
fuel
tank
cap
vent
hole.
b.
Air
cleaner
can
be
clogged
with
fine
snow.
CARBURETOR ADJUSTMENTS
The
carburetor
is
adjusted
at
the
factory
and
under
normal
operating
conditions
will
not
require
readjust-
ment.
If
adjustmentisnecessary
becauseoffuel
values
and/orair
conditions,
the
following
procedureisrecom-
mended:
a.
Turn
high
speed
adjustment
screw
(center
ver-
tical
screwontopofcarburetor)
counter-clockwise
two
full
turns
from
closed
position
and
start
engine.
b.
After
engine
has
reached
normal
operating
tem-
perature,
accelerate
and
check
response.
Operate
engine
under
full
load
and
adjust
high
speed
needle
for a
slightly
richer
mixture
for
improved
cooling
and
greater
power.
c.Ifengine
misses
and
backfires,
high
speed
mixture
is
too
lean.
To
correct-high
speed
adjustment
screw
should
be
turned
counter-clockwise,
74:
turn
atatime,
until
conditioniscorrected.
d.Ifengine
shows
sooty
exhaust
and
is
sluggish,
mixture
is
too
rich.
To
correct-high
speed
adjustment
screw
should
be
turned
clockwise
until
engine
runs
smoothly.
e.
To
make
final
check
of
high
speed
adjustment,
operate
under
full
load
and
make
corrections
to
achieve
smooth
operation.
f.
Idle
speediscontrolled
by
stop
screw
on
car-
buretor
throttle
shaft
and
should
be
set
at
a
speed
not
less
than
1000
RPM.
g.
Adjustments
to
idle
mixture
screw
(angled
screw
on
sideofcarburetor)
and
idle
stop
screw
should
be
made
at
the
same
time
as
each
affects
the
other.
Adjust
until
engine
idles
smoothly.
WARNING:
Do not use force on high speed needle
or
idle
screw-they
will
be
damaged.
RECOIL
STARTER
The
starter
hasadie
cast
aluminum
housing.
A
friction
shoe
assembly,
under
spring
tension,isusedtoengage
in
the
drive
cup
when
starter
handle
is
pulled.
The
drive
cupisheldinplaceonenginebythe
flywheel
nut.
A
pin
on
the
cupisengagedinthe
crankshaft
keyway
to
prevent
slippageofthe
drive
cup.
1.
To
Align
Starter
a.
Placeindesired
position
on
blower
housing
with
centering
pin
engagedincenter
holeofcrankshaft.
If
centering
pinistoo
short
to
reach
crankshaft,
pull
pin
outtocorrect
length
withapairofpliers.
2.
Operating
Tips
a.
Be
sure
starter
screenISkept
clean
when
engine
5
is
operating.
Severe
damage
may
result
from
overheating.
b.
After
starting
engine,
return
cable
slowly.
Re-
leasing
handle
when
cableisextended
will
shorten
lifeofstarter.
c.
Useasteady
pulltostart
engine.
Jerking
cable
to
the
end
will
resultinwear.
d.
Pull
handle
so
that
cable
will
remain
centered
in
guides.
If
for
any
reason
recoil
starter
should
not
operate,
starter
assembly
canberemoved
and
engine
cranked
witharope.
The
starter
cup
will
serveasa
rope
pulley.
BrentChalmers.com
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