Kohler K91RT User manual

-KOHLER
ENGINES
4-CYCLE
• SHORT-STROKE
•
AIR-COOLED
M0DEL
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-
vision of skilled 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 with a heavy
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 hole of oil fill
plug is open. If oil bubbles out of vent hole of
oil fill plug, there is too 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. Little or no choking will be necessary when
engine is warm. 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 screw is set at factory for fast idle. Close
throttle and set at full choke. When engine has
started, open choke slowly, making adjustments
1
as engine warms up. Use Autolite AR8 spark
plug or equivalent.
Below _250 F.
Apply heat to engine cylinder head, spark plug,
and oil pan. Engine will start at -40 0 F. 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 out of service for a considerable length of
time.
4. Precautions
Stop engine before filling fuel tank. Avoid spilling
gasoline on a hot engine. Always use fresh, clean
gasoline.
a. Avoid lnJuries. Always disconnect spark plug
cable before making any adjustment to machine
powered by engine.
Cont. on page 4
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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
1220541
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 I1I
A-220092
I Dipstick-assembly
97 1
220873
Disc,regulating
50 1
220854
Cover, duct
51 1 220855
Body, duct
EXHAUST GROUP
IGNITION GROUP
31
235308
Element
2
X-81-1 Nut, hex. 7.4:-20
41
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, lock 8 I.E.T.
5 2
X-132-1 Screw, H.C. >i-20xYs
56 1
A-220145
Muffler-assembly
1 X-25-48
Washer 8
64
X-132-5
Screw, H.C. >i-20x%
FLYWHEEL GROUP
1
X-25-63
Washer >i
81
220049
Baffle, head
Washer, lock Vt6
105 2
X-67-22
Screw, self tapping 10
91
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 2220011 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
4I
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, 4 H.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' 120
I
1I
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 1220211
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 1220492
Lock, connecting rod
35
1
X-271-15 Seal, front oil 91 1
220218
Gasket, cover
127 2220491
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 housing at filler hole
130 1
220003
Pin, piston
39
1220071
Gasket, bearing plate
until oil
runs from oil level hole at lower 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%
42
I1I
220433 I Crankshaft
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, drive w /screen
CYLINDER HEAD GROUP
1
X-269-13 Ring, snap
43
I1
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
1220131
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
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GEAR REDUCTION
The reduction unit is a gear type running in oil. Tl,1e
drive gear is machined on the crankshaft and the driven
gear is keyed and pressed onto the power-take-off shaft.
The shaft is supported 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 unit to oil level hole. Use same grade of oil
recommended for engine.
b. The reduction gear is vented through the oil fill
plug. This vent should be checked daily to see
that it is 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 gear to protect 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 should be wrapped around shaft to prevent
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.
KoHLE R oFKoHLER
EN405 6M-7-62-Z
6
LITHO IN U. S. A.
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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 afew 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
setting or run 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 oil in crankcase.
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 plug to .025.
Use Autolite AR-8 plugs, or equivalent, 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 #5 grade
oil.
4. Instructions for Storing
If engine is to be out of service 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 surfaces of engine.
e. Spread a light film of oil over any exposed sur-
faces of engine subject to corrosion.
f. Pour tablespoon of oil 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 list of troubles 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. Dirty or clogged intake screen, shroud or .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 Missing at High Speed
a. Spark plug gap too wide.
b. Improper carburetor adjustment or lack of fuel.
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.
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c. Partially fouled spark plug.
d. Defective ignition timing.
6. Knocking
a. Fuel octane rating too low. Use a good 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.
Water in fuel.
c.
Faulty choke control.
d. Improper fuel mixture.
e. Loose ignition system connection.
f. Air leaks in manifold 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 coil or condenser.
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 adjustment is necessary because of fuel values
and/ or air conditions, the following procedure is recom-
mended:
a. Turn high speed adjustment screw (center ver-
tical screw on top of carburetor) 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. If engine misses and backfires, high speed mixture
is too lean. To correct-high speed adjustment
screw should be turned counter-clockwise, 74:
turn at a time, until condition is corrected.
d. If engine 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 speed is controlled 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 side of carburetor) 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 has a die cast aluminum housing. A friction
shoe assembly, under spring tension, is used to engage
in the drive cup when starter handle is pulled. The
drive cup is held in place on engine by the flywheel nut.
A pin on the cup is engaged in the crankshaft keyway
to prevent slippage of the drive cup.
1. To Align Starter
a. Place in desired position on blower housing with
centering pin engaged in center hole of crankshaft.
If centering pin is too short to reach crankshaft,
pull pin out to correct length with a pair of pliers.
2. Operating Tips
a. Be sure starter screen IS kept clean when engine
5
is operating. Severe damage may result from
overheating.
b. After starting engine, return cable slowly. Re-
leasing handle when cable is extended will shorten
life of starter.
c. Use a steady pull to start engine. Jerking cable
to the end will result in wear.
d. Pull handle so that cable will remain centered
in guides.
If for any reason recoil starter should not operate,
starter assembly can be removed and engine cranked
with a rope. The starter cup will serve as a rope
pulley.
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