Kohler KT17 User manual

Section 1 - GENERAL INFORMATION ............... .
Section 2- TROUBLESHOOTING ................... .
Section 3- AIR INTAKE SYSTEM ................... .
Section 4- FUEL SYSTEM AND GOVERNOR ........ .
Section 5- LUBRICATION SYSTEM ................. .
Section 6- ELECTRICAL SYSTEMS & COMPONENTS ..
Section 7- DISASSEMBLY .......................... .
Section 8 - ASSEMBLY ............................. .
SUBJECT INDEX ...................................... .
1
'
I
I
3-10
11-13
15-18
19-26
27-28
29-40
41-52
!
53-69
71-74

-------INTRODUCTION-------
Long-life strengthand on-the-job durability are designed and built into
these Kohler engines.
Parts subject to most wear and tear -like cylin-
ders, crankshaftsandcamshafts -aremadefrom precision-formulated
cast iron ... and because the cast iron cylinders can be rebored, these
engines can last even longer.
These Kohler engines are easy
to service. All routine service parts -
points, condenser, spark plugs, air cleaner, carburetor -are easily and
quickly accessible.
This manual provides the technician with information andinstructions
for servicingandrepairingtheKT17 & KT19 Series II, and KT17- KT19-
KT21 engines. It is recommended the technician study the procedures
and illustrations in this manual and use them
as references when per-
forming repairs.
KT engines use one of two types of Pressurized Lubrication Systems.
KT SMESJ[ engines have a Full Pressure lu-
bricationsystem. TheSpecification Numbers
for
KT Series II models are:
KT17 Series
II -Specifications 24300 And
Higher
KT19 Series
II -Specifications 49200 And
Higher
Other KT17-KT19·KT21 engines use a Pres-
surized Spray lubrication system. The Speci·
fication Numbers for those models are:
KT17 -Specifications 24299
And Lower
KT19- Specifications 49199 And Lower
KT21 -All Specifications
Refer to Section 5 - Lubrication System for additional information.
The SMESJ[logo appears throughout this
manual
to identify information and service
procedures unique
to the Series II models.
2

SECTION 1 -GENERAL INFORMATION
ENGINE IDENTIFICATION
NUMBERS
When ordering parts, or in any communication
involving an engine, always include the Model,
Specification,
and Serial numbers of the engine.
The Model and Specification numbers appear on
the engine identification decal, and directly below
it is the decal with the Serial number. Both decals
are located on the top of the engine shrouding.
The significance of each of- these numbers is
shown below.
Serial
Number Specification And Model Number
Figure 1·1. Engine Identification Decals
Engine Model Code
24- KT17
32- KT21
49- KT19
Year of Manufacture
90-94 1978
95-99 1979
100-109 1980
110-119 1981
120-129 1982
130-139 1983
140-149 1984
u-oHLER@illl~Dilll@ 'l
17HP I Variation
of
Basic Engine
Spec.n. 24102d·~=---~---f--~~~~~~--~
Model no. KT17§.- Version Code
Refer
to owners manual
for operation and
maintenance
instructions
I
W' KOHLER COMPANY
I~ KOHLER WISCONSIN USA
Serial
No.
3
G- Tapered Crankshaft
P- Threaded Crankshaft
S - Electric Start
Q- Quiet Model
EP -Electric Plant
Factory Code
•

SECTION 1
GENERAL INFORMATION
FOR YOUR SAFETY
This symbol points out important safety WARN-
INGS and CAUTIONS which should be followed
at all times. Follow WARNINGS to ensure the
safety of yourself and others. Follow CAUTIONS
to prevent damage to the engine or equipment.
General Safety Warnings
Before working on engine orequipment,disconnect
battery cables from battery. Always disconnect
the negative (ground) cablefirst. When connecting
battery cables, always connect the negative
(ground) cable last.
Never inhale exhaust fumes-all engine exhaust
contains poisonous carbon monoxide. Never run
the engine in a closed building or a confined area
without adequate ventilation.
Never operate engine or equipment with shrouds,
covers or
safety guards removed. Hands, feet,
clothing, or
hair can get caught in moving parts
resulting in personal injury.
Never touch the engine cylinder block. exhaust
system, or cylinder head while the engine is run·
ning-or immediately after it is turned off. These
parts can get hot and could burn you.
Never touch electrical wires or components while
engine is running-they may be sources of electri·
cal shock, which could severely injure or kill you.
Make sure cleaning solvents and other flammable
liquids areproperly identified and stored in cover·
ed containers safely away from the danger of
combustion from open flames, sparks, etc.
------------------------------------
OIL RECOMMENDATIONS
The importance if checking and changing crankcase
oil cannot be overemphasized. Insufficient, or dirty
oil causes premature engine wear and failure.
Oil Type
Use high quality detergent oil of API (American Pe-
troleum Institute) service class SF or SG. Select the
viscosity based on the air temperature at the time of
operation as shown below:
Recommended SAE Grades Oil Change
Straight 3D-weight oil is recommended. Do not use
multi-viscosity oils above 32°F (D°C) as consider-
able increases in oil consumption and combustion
deposits will result.
NOTE: Using other than service class SF or SG oil
or extending oil change intervals longer than
recommended can cause engine damage
which is not covered by the engine warranty.
A logo
or symbol on oil containers identifies the API
service class and SAE viscosity grade.
4
On a new engine, change oil after the first 5 hours
of operation and then
every 25 operating hours
thereafter.
Drain oil while the engine is still warm from operation
-it flows freely and
carries away more impurities.
Better drainage will result if
the engine is tilted
slightly toward
the oil drain. After draining, reinstall
drain plug.
Fill with
proper viscosity oil to the "F" mark on dip-
stick. Always
check level on dipstick before adding
more oil. Engine must be level for accurate read-
ing. Overfilling can
cause engine to overheat.
On overhauled engines or those rebuilt with a new
shortblock, use straight 3D weight service class SF
or SG for the first 5 hours of operation. Change the
oil after this initial run-in period. Refill with oil as
specified in oil
type.
Checking Oil
Before checking oil level, clean areas around dip-
stick and oil fill
to prevent dirt from falling into en-
gine.

Always check oil with engine stopped and on a level
surface.
Check oil before each use when the engine is cool
and the oil
has drained back into the sump. Add
oil, if low, to bring level up to, but not over the "F"
mark on the dipstick.
NOTE: Do not operate engine with oil level below
the "L" mark or over the "F" mark on the
dipstick.
t
Operating
Range
~
FUEL RECOMMENDATIONS
WARNING: Explosive Fuel!
A Gasoline is extremely flammable
.. and its vapors can explode if ig-
nited. Store gasoline only in ap-
proved containers, in well-venti-
lated, unoccupied buildings, away
from sparks
or flames. Do not fill
the fuel tank while the engine is hot
or running, since spilled fuel could
ignite
if it comes in contact with hot
parts or sparks from ignition. Do not
start the engine near spilled fuel.
Never use gasoline as a cleaning
agent.
General Recommendations
Purchase gasoline in small quantities and store in
clean, approved containers. A container with a ca-
pacity of 2 gallons or less with a pouring spout is
recommended. Such a container is easier to handle
and helps eliminate spoilage during refueling.
Do not use gasoline left over from the previous sea-
son, to minimize gum deposits in your fuel system
and to insure easy starting.
Do not add oil to the Qasoline.
Do not overfill the fuel tank. Leave room for the
fuel to expand.
5
SECTION 1
GENERAL INFORMATION
On gravity feed systems, turn the fuel valve off
when the engine is not in use. Keep the vent hole
in the tank filler cap open. If vent hole is plugged,
pressure may build up in tank causing flooding or
dangerous spraying of gasoline when cap is re-
moved. A vacuum may also be created which
could disrupt fuel flow to the carburetor during en-
gine operation.
Fuel Type
For best results, use only clean, fresh, unleaded
gasoline with a pump sticker octane rating of 87 or
higher. In countries using the Research method, it
should be 90
octane minimum.
Unleaded gasoline is recommended, as it leaves
less combustion chamber deposits. Leaded gaso-
line may be used in areas where unleaded is not
available and exhaust emissions are not regulated.
Be aware however, that the cylinder head will re-
quire more frequent service.
Gasoline/Alcohol blends
Gasohol (up to 10% ethyl alcohol, 90% unleaded
gasoline by volume) is approved as a fuel for Kohler
engines. Other gasoline/alcohol blends are not ap-
proved.
Gasoline/Ether blends
Methyl Tertiary Butyl Ether (MTBE) and unleaded
gasoline blends (up to a maximum of 15% MTBE by
volume) are approved as a fuel tor Kohler engines.
Other gasoline/ether blends are not approved.
SERVICE SCHEDULE
NOTE: Intervals stated are for good, clean opera-
ting conditions. Service more frequently (even
daily)
if extremely dusty or dirty conditions prevail.
Service Frequency
Change Lube Oil ............................. 25 hrs.
Service Precleaner ............................ 25 hrs.
Check Air Cleaner ............................ 50 hrs.
Clean Cooling Fins and External Surfaces ...... 50 hrs.
Check Spark Plugs .......................... 100 hrs.
Check Compression ......................... 500 hrs.
Service Breaker Points ....................... 500 hrs.
Check Ignition Timing ....................... 500 hrs.
Check Valve & Tappet Clearance .............. 500 hrs.
Service Cylinder Head
....................... 500 hrs.
Service Starting Motor Drive .................. 500 hrs.
'250 hours when leaded gasoline is used.
The above service
procedures should also be performed as part
of any seasonal tune-up.

SECTION 1
GENERAL INFORMATION
AIR CLEANER SERVICE
KT engines have tear drop, square, or round air
cleaners with dry type filter elements. Elements
should be checked every 50 operating hours and
replaced when dirty. Check and replace more often
under extremely dirty, dusty conditions.
Replace
with a genuine Kohler element. Carefully
handle element -do not use if sealing surfaces are
damaged.
Somemodels are equipped with Precleaners, which
should be washed and oiled every 25 hours-see
Section 3 for details, and for proper disassembly
and reassembly procedures of air cleaners.
Air lnlake
Tube
Housing
COOLING SYSTEM SERVICE
Air is drawn into the cooling shrouds by fins on the
flywheel. The air intake screen and cooling fins on
the cylinder heads and barrels must be kept clean
and unobstructed at all times.
CAUTION:
Do not operate engine with blower
housing or cooling shrouds removed.
They direct air flow past cooling fins
and removal results in improper air
circulation, overheating and engine
damage.
External surfaces (see Figure 1-2), must be kept
clean, free of oil and dirt accumulation. Dirty
external surfaces result in poorcooling efficiency.
Figure 1-2. Keep These Areas Clean
SPECIFICATIONS AND TOLERANCES
GENERAL SPECIFICATIONS
KT17 KT19 KT21
Bore (Nominal).............. 3.125" (79.375 mm) 3.125" (79.375 mm) 3.312" (84.125 mm)
Stroke . . . . . . . . . . . . . . . . . . . . . 2.750" (69.8 mm) 3.063" (77.8 mm) 3.063" (77.8 mm)
Displacement ............... 42.18 cu. in. (691.4 cc) 47 cu. in. (770.4 cc) 52.76 cu. in. (864.7 cc)
Horsepower at 3600 RPM...... 17 (12.7 kW) 19 (14.2 kW) 21 (15.7 kW)
Weight . . . . . . . . . . . . . . . . . . . . . 1181b. (53.5 kg)
121 lb. (54.9 kg) 1241b. (56.2 kg)
Oil Capacity................. 3 pts. (1.42 L) 3 pts. (1.42 L) 3 pts. (1.42 L)
Spark Plug Gap.... . . . . . . . . . . .025" (0.635 mm) .025" (0.635 mm) .025" (0.635 mm)
Spark Plug Size.............. 14 mm 14 mm 14 mm
SparkPiugReach............ .460 (11.7mm) .460" (11.7mm) .460" (11.7mm)
Spark Plug Type ............ _ .............................. Champion RBL15Y or Equivalent .............................. .
Breaker Point Gap............ .017/.023" (.432/.580 mm) .017/.023" (.432/.580 mm) .017/.023" (.432/.580 mm)
6

SECTION 1
GENERAL
INFORMATION
TORQUE SETTINGS -Special KT17 KT19 KT21
Spark Plugs (ft. lbs.) ......... .
Flywheel Retaining Screw
{ft. lbs.) ............•...•..
Manifold Screws (in. lbs.) ..... .
Closure Plate Screws
10-15 {14-20 N m)
{1.4-2.1
kgm)
40 {54 N m) {5.5 kgm)
150 {17 N m) {1.7 kgm)
10-15 {14-20Nm)
{1.4-2.1 kgm)
40 {54 N m) {5.5 kgm)
150 {17 N m) {1.7 kgm)
10-15 {14-20 N m)
{1.4-2.1
kgm)
40 {54 N m) {5.5 kgm)
150 {17 N m) {5.5 kgm)
{in. tbs.) . . . . . . . . . . . . . . . . . . 150 {17 N m) {1.7 kgm) 150 {17 N m) {1.7 kgm) 150 {17 N m) {1.7 kgm)
............... (See Closure Plate Diagram Page 62 for Correct Tightening Sequence) ............. .
Cylinder Head Screws*
{ft. tbs.) ...........•.......
15-20 {20-27 N m) 15-20 {20-27 N m) 15-20 {20-27 N m)
{2.8-3.7
kgm) {2.8-3.7 kgm) {2.8-3.7 kgm)
.............. (See Cylinder Head Diagram Page 63 for Correct Tightening Sequence) ............. .
Cylinder Barrel Stud Nuts
{in. lbs.) . . . . . . . . . . . . . . . . . . 360 {40.5 N m) {4 kgm) 360 {40.5 N m) {4 kgm) 360 {40.5 N m) {4 kgm)
.................. {See Barrel Diagram Page 62 for Correct Tightening Sequence) ................ .
Connecting Rod Screws*
(in. lbs.) ................. .
Connecting Rod Nuts*
(Posi-Lock Rods)
New Rod {in. lbs.) ......... .
Used Rod (in. lbs.)
....... .. .
Crankcase Stud Nuts
200 {23 N m) {2.3 kgm)
140 {15.8 Nm) (1.6 kgm)
100 {11.3 Nm) (1.2 kgm)
200 {23 N m) {2.3 kgm)
140 {15.8 Nm) {1.6 kgm)
100 {11.3 Nm) {1.2 kgm)
200 {23 N m) {2.3 kgm)
{in. lbs.) . . . . . • . . . . . . . . . . . . 260 {29 N m) {3 kgm) 260 {29 N m) {3 kgm) 260 {29 N m) {3 kgm)
Crankcase Cap Screws .......................... (See Crankcase Diagram Page 60 for Torque and Sequence) ............. ..... .
Crankcase Slot Head Screw
(in. lbs.) ................. . 35 {4 N m) {0.4 kgm)
35 {4 N m) {0.4 kgm)
35 {4 N m) {0.4 kgm)
·Lubricate with oil at assembly.
TOLERANCES, FITTED PARTS
Crankcase End Play
(Ball Bearing) ............. .002/.023" {.051/.580
mm)
.002/.023" {.051/.580
mm) .002/.023" {.051/.580
mm)
Crankshaft End Play
(Sleeve Bearing) ........... .002/.014" {.051/.355
mm)
.002/.014" {.051/.355
mm) .002/.014" {.051/.355
mm)
Crankshaft Running Clearance
(Sleeve Bearing) ........... .0013/.0033" {.034/.083 mm) .0013/.0033" {.034/.083 mm)
.0013/.0033" {.034/.083 mm)
Camshaft End Play ........... .003/.013" {.077/.330 mm) .003/.013" {.077/.330
mm) .003/.013" {.077/.330
mm)
Camshaft Bearing ............
.0010/.0025" {.025/.063 mm) .0010/.0025" {.025/.063 mm)
.0010/.0025" {.025/.063 mm)
Connecting Rod to
Piston Pin Running .........
.0006/.0011" {.016/.027 mm) .0006/.0011" {.016/.027 mm)
.0003/.0008" {.008/.020 mm)
Connecting Rod to
Side Play on Crankpin ...... .005/.016" {.13/.41
mm)
.005/.016" {.13/.41
mm) .005/.016" {.13/.41
mm)
Connecting Rod to
Crankpin Running .......... .0012/.0024" {.030/.060
mm)
.0012/.0024" {.030/.060
mm) .0012/.0024" {.030/.060
mm)
Piston Thrust Face to Bore
Running
(@Gage Dia.) ...... .006/.008" {.15/.20
mm)
.0065/.0085" {.165/.216
mm) .0065/.0085" {.165/.216
mm)
Rings- Side Clearance .... Top .002/.004" {.051/.10
mm) .002/.004" {.051/.10 mm) .002/.004" {.051/.10
mm)
..... lnt .001/.003" {.025/.077
mm)
.0011.003" {.025/.077
mm) .0015/.004" {.038/.01 mm)
..... Oil .001/.003" {.025/.077
mm)
.001/.003" {.025/.077
mm) .001/.003" {.025/.077
mm)
Rings- End Gap ............. .010/.020" {.254/.508 mm) .010/.020" {.254/.508 mm)
.010/.020" {.254/.508 mm)
Wrist Pin to Piston Boss-
Max ......................
.0003" {.008 mm) .0003" {.008 mm)
.0003" {.008 mm)
Wrist Pin to Rod ............. .0006/.0011" {.016/.027
mm)
.0006/.0011" {.016/.027
mm) .0003/.0008" {.008/.020
mm)
Intake Valve to Tappet-
Cold ..................... .003/.006" {.076/.150
mm)
.003/.006" {.076/.150 mm)
.003/.006" {.076/.150 mm)
Exhaust Valve to Tappet -
Cold .....................
.011/.014" {.279/.355 mm) .011/.014" {.279/.355 mm) .011/.014" {.279/.355
mm)
Valve Lift -Zero Lash .........
.280" {7.11 mm) .280" {7.11 mm)
.280" {7.11 mm)
Intake Valve Stem to Guide-
Max. .....................
.0045" {.114mm)
.0045" {.114
mm) .0045" {.114
mm)
Exhaust Valve Stem to Guide-
Max. ..................... .0065" {.165
mm)
.0065" {.165
mm) .0065"
{.165mm)
7

SECTION 1
GENERAL INFORMATION
TOLERANCES, FITTED PARTS (Cont'd)
KT17 KT19
KT21
Tappet Clearance in Guide-
Max . ..................... .0005/.0024" (.013/.060 mm) .0005/.0024" (.013/.060 mm) .0005/.0024" (.013/.060 mm)
Valve Guide Interference
Fit in Cylinder ............. .005/.002" (.013/.051 mm) .005/.002" (.013/.051
mm) .005/.002" (.013/.051 mm)
Valve Guide Ream
Diameter
......... ......... .312/.313" (7.925/7.950 mm) .312/.313" (7.925/7.950 mm) .312/.313" (7.925/7.950 mm)
Pump Shaft to Crankcase
Running
.................. .001 0/.0025" (.025/.063 mm) .0010/.0025"
(.025/063 mm) .0010/.0025" (.025/.063 mm)
Pump Drive Gear End Play ..... .010/.029" (.254/.736 mm) .01 0/.029" (.254/.736 mm) .010/.029" (.254/.736
mm)
WEAR TOLERANCES
Cylinder Bore-
New Diameter ............. 3.125" (79.375 mm) 3.125" (79.375 mm) 3.312" (84.125 mm)
Cylinder Bore-
Max. Wear Diameter ........
3.128" (79.45 mm)
3.128" (79.45 mm) 3.315" (84.201
mm)
Cylinder Bore -
Max. Taper
................
.0015'' (.038 mm) .0015'' (.038 mm) .0015" (.038 mm)
Cylinder Bore-
Max. Out of Round ......... .002" (.05 mm) .002" (.05mm) .002" (.05mm)
Crankshaft Crankpin
New Diameter
............... 1.3733 (34.882/34.895
mm) 1.3733/ (34.882/34.895 mm) 1.4993/ (38.082/38.095 mm)
1.3738" 1.3738" 1.4998"
Series II ...... ............
1.3733/ (34.882/34.895
mm)
1.4993/ (38.082/38.095
mm)
1.3738" 1.4998"
Crankshaft Crankpin-
Max. Out of Round ......... .0005" (.013 mm) .0005" (.013 mm) .0005" (.013 mm)
Crankshaft Crankpin-
Max. Taper .. .............. .001" (.025 mm) .001" (.025 mm) .001" (.025 mm)
Crankshaft Main Bearing
New Diameter ............. 1.7412/ (44.226/44.252 mm) 1.7412/ 44.226/44.252 mm) 1.7412/ (44.226/44.252 mm)
1.7422" 1.7422" 1.7422"
Crankshaft Main Bearing-
Min. Diameter .............
1.7407" (44.22 mm) 1.7407" (44.22
mm) 1.7407" (44.22 mm)
Connecting Rod Crankpin
Bore -
New Diameter
...............
1.3750/ (34.925/34.943
mm) 1.3750/ (34.925/34.943 mm) 1.5010/ (38.125/38.143 mm)
1.3757" 1.3757" 1.5017"
Series II ............ ......
1.3750/ (34.925/34.943 mm) 1.5010/ (38.125/38.143
mm)
1.3757" 1.5017"
Connecting Rod Crankpin
Bore- Max. Diameter
............... 1.3765 (34.963
mm)
1.3765 (34.963 mm) 1.5025 (38.164 mm)
Series II .......... ........ 1.3765 (34.963 mm) 1.5025 (38.164 mm)
Connecting Rod Wristpin
Bore- New Diameter .... .... .62565" (15.891
mm)
.7511" (19.078 mm) .85975" (21.837 mm)
Piston Thrust Face-
Max. Wear Dia.* ............ 3.1165" (79.159 mm) 3.1165" (79.159 mm) 3.303" (83.896 mm)
*Measured just below oil ring at right angles to pin.
8

SECTION1.
GENERAL INFORMATION
TORQUE SETTINGS -General
Tightening Torque Into Cast iron or Steel
00@
Size Grade 2 Grade 5 Grade 8
8-32 20 in. lb.
25 in. lb.
10-24 32 in. lb. 40 in. lb.
10-32
32 in. lb. 40 in. lb.
1/4-20 70 in. lb. 115 in. lb. 165 in. lb.
1/4-28 85 in. lb. 140 in. lb. 200 in. lb.
5/16-18 150 in. lb. 250 in. lb. 350 in. lb.
5/16-24 165 in. lb. 270 in. lb. 30 ft. lb.
3/8-16 260 in. lb. 35 ft. lb. 50 ft. lb.
3/8-24 300 in. lb. 40ft. lb. 60ft. lb.
7/16-14
35 ft. lb. 55 ft. lb.
80ft. lb.
7/16-20 45 ft. lb. 75ft. lb. 105ft. lb.
1/2-13 50 ft. lb. 80 ft. lb. 115ft. lb.
1/2-20 70 ft. lb. 105ft. lb. 165 ft. lb.
9/16-12
75 ft. lb.
125ft. lb. 175 ft. lb.
9/16-18 100ft. lb. 165ft. lb. 230 ft. lb.
5/8-11
110ft. lb. 180ft. lb. 260 ft. lb.
5/8-18 140ft.
lb. 230 ft. lb.
330ft. lb.
3/4-10 150 ft. lb. 245 ft. lb.
350ft. lb.
3/4-16 200 ft. lb.
325ft.
lb. 470ft. lb.
SPECIAL TOOLS
Service and repair procedures will be made easier
by using proper tools. Use only the correct size tool
to fit each size of fastener.
Some procedures detailed in this manual recom-
mend use of tools which can be made by the service
man. (Figures 1-5 and 1-6)
Some procedures require the use of special Kohler
designed tools (Figures 1-3 and 1-4) which are
available from your Kohler distributor.
Figure 1-3. Flywheel Strap Wrench (52 455 03)
Replacement Strap (52 445 04) 9
Tightening Torque Into Aluminum
Size
8-32
10-24
1/4-20
5/16-18
00@
Grade 2 Grade 5 Grade 8
20 in. lb. 20 in. lb. 20 in. lb.
32 in. lb.
32 in. lb.
32 in. lb.
70 in. lb. 70 in. lb.
70 in. lb.
150 in. lb. 150 in. lb. 150 in. lb.
Conversions
in. lbs. x .083 -ft. lbs.
ft. lbs. x 12 -in. lbs.
ft. lbs. x .1383- kgm
ft. lbs. x
1.3558- N m
WARNING: Suitable
eye protection through the
use of safety glasses, goggles, or face
hood should be worn for any proce-
dure involving the use of compressed
air, punches, hammers, chisels, drills,
or
grinding tools.
Part No. 52 455 02 (9/16")
Figure 1-4. Barrel Wrench

SECTION 1
GENERAL INFORMATION
How to make a "U" Tube Manometer
(Used to measure Crankcase Vacuum. See Section 2
- Troubleshooting.)
1. Cut a piece of 112'' plywood so it measures 10"x
30" as in Figure 1·5.
2. Fasten a six foot length of 112" O.D. clear
plastic tubing to the plywood board as shown in
Figure 1·5. Make a gradual rather than a sharp
bend in the tube.
3. Inside the "U" formed by the tubing, measure
off at least a 24" segment on the plywood board
between the straight sides of the "U". Divide the
segment into one inch increments and mark
these increments on the board. Start with the
middle increment as zero and number in both
directions.
Shut-off Clamp
Measure Difference
Between Columns
;'
t
-3-
v
=-2 ::::
=-1-=
c
-· 0-~
u
-1-
2-
M
-3
·-
:
·.·
4. Drill a 112" hole in the center of a rubber stopper
the size to be a snug fit in the engine oil fill hole.
Insert long end oftube thru stopper hole.
Figure 1-5. "U" Tube Manometer
5. Add a shut-off valve or clamp in front of the
stopper to prevent engine from drawing water
into crankcase under cranking conditions.
6. Pour colored water into the tube until the level
reaches the halfway (0) mark of the scale marked
on the plywood board.
f--r--~1-...L--F-------+i·l
+-:::;:::=======t.l 1).45°
t !.. : ___ l::..r-r'-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_- .. -::-\--,_1_ t
G H 32 I I - C
LBI-- ~ __________________ vrt:D t
~~~-
8
-------A--------~.1
PTO END DRIVER FLYWHEEL END DRIVER
Dimension
A
B
c
D
E
F
G
H
Size Dimension Size
8.5625 A 5.00
0.1563 B 0.0313
1.5605 c 1.385
0.125 DIA. D 0.125 DIA.
1.875 E 1.6250
7.3125 F 4.500
3.00 G 2.00
2.370 H 1.75
Figure 1-6. Seal Driver (P.T.O.)-Seal Driver (Flywheel)
10
f
E
*
p
R
E
s
s
u
R
E
:
:

SECTION 2- TROUBLESHOOTING
When troubles occur, don't overlook simple causes
which might seem too obvious to be considered. A
starting problem could, for example, be attributed
simply to an empty fuel tank. The chart below lists
some common causes of engine troubles- use this
as a guide to locate causing factors.
Engine Starts But Fails To Keep
Running
Restricted fuel tank vent.
Carburetor not properly adjusted.
Broken choke cable.
Dirt or water in fuel system.
Breaker points not properly
adjusted.
Loose wires or connections.
Defective head gasket.
Faulty condenser.
Faulty fuel shutdown control.
Engine Runs But Misses
Breaker points not properly
adjusted.
Defective spark plugs.
Loose wires or connections.
High tension leads loose at coil.
Carburetor float leaking or not
properly adjusted.
Dirt or water in fuel system.
Wrong valve clearance.
Faulty coil.
Air intake or shrouding plugged.
Engine Misses Under Load
Defective spark plugs.
Carburetor not properly adjusted.
Incorrect spark plugs.
Breaker points not properly
adjusted.
Ignition out of time.
Dirt or water in fuel system.
Engine Will Not Idle
Idle speed too slow.
Idle mixture needle not properly
adjusted.
Dirt or water in fuel system.
Restricted fuel tank filler cap.
Defective spark plugs.
Wrong valve clearance.
Low engine compression.
Engine Overheats
Air intake or shrouding plugged.
Carburetor not properly adjusted.
Too much oil in crankcase.
Crankcase low on oil.
Excessive
engine load.
Engine Knocks
Engine out of time.
Excessive
engine load.
Crankcase low on oil
Engine Uses Excessive Amount
of Oil
Clogged breather assembly.
Breather not assembled properly.
Worn or broken piston rings.
Worn cylinder bores.
11
Wrong size piston rings.
Worn valve stems and/or valve
guides.
Incorrect oil viscosity.
Engine Will Not Crank
Hydrostatic drive not in neutral.
Battery discharged or defective.
PTO drive engaged.
Defective safety switch.
Defective starter.
Defective solenoid.
Loose electrical connections.
Defective key switch.
Engine Cranks But Will Not Start
Empty fuel tank.
Restricted fuel tank vent.
Fuel
shut-off valve closed.
Clogged or restricted fuel line.
Breaker points worn or pitted.
Defective spark plugs.
Battery not fully charged.
Loose electrical connections.
High tension leads loose at coil.
Faulty condenser.
Defective ignition coil.
Dirt in fuel system.
Faulty fuel shutdown control.
•

SECTION 2
TROUBLESHOOTING
Engine Starts Hard
Defective spark plugs.
Engine Loses Power
Crankcase low on oil.
Breaker points worn or pitted.
Loose wires or connections.
Restricted fuel tank vent.
Clogged or restricted fuel line.
Broken choke or throttle cable.
Dirt or water in fuel system.
Carburetor not properly adjusted.
Wrong valve clearance.
Air intake or shrouding plugged.
Excessive engine load.
Restricted air filter.
Dirt or water
in fuel system.
Carburetor not properly adjusted.
Defective spark plugs.
High tension leads loose at coil.
Too much oil in crankcase.
Head gasket leaking. Low engine compression.
Low compression. Worn cylinder bore.
EXTERNAL ENGINE INSPECTION
Before cleaning or disassembling an engine,
check the external condition-it may give clues
to
what may be found inside the engine once it is
disassembled.
D Check for buildup of dirt and debris on the
engine block and other external surfaces. Pay
close attention to the air intake screen and
cooling fins-a plugged screen or fins can cause
overheating.
D Check for obvious fuel and oil leaks and dam-
aged components.
If excessive oil leakage is evident, this may
indicate an improperly serviced breather sys-
tem. Normally, an engine operates with a slight
vacuum in the crankcase. If pressures build up
in the crankcase from a clogged breather or
piston blow by, oil will be forced out at oil seals,
gaskets, or any other availabile spot.
D Check the air cleaner cover and baseplate for
damage or indications of improper fit and seal.
Also check the seal on the air cleaner cover
wing nut-a missing or damaged seal could
allow dirt to enter the engine.
D Check the air cleaner element. Look for holes,
tears, cracked or damaged sealing surfaces, or
other damage that could allow dirt to enter
engine. Also note if the element is plugged or
restricted, which would indicate that it has
been underserviced.
D Check the carburetor throat for dirt. Dirt in the
throat is further indication that the air cleaner
is not functioning properly.
12
D Check the oil level. Note if the oil is at the
recommended level or if low or overfilled.
D Check the condition of the oil. Drain the oil into
a container-the oil should flow freely. Check
for metal chips and other foreign particles.
NOTE: It is good practice to drain oil at a
location away from the work bench. Be sure to
allow ample time for complete drainage.
Sludge is a natural by-product of combustion,
and a small accumulation is normal. Excessive
sludge formation could indicate several things:
the oil has not been changed often enough,
operating with improper ignition timing, or an
overrich carburetor adjustment, to name a few.
Cleaning Engine
After checking the external condition of the engine,
it should be thoroughly cleaned prior to disassem-
bly. Also, clean all parts as the engine is dis-
assembled. Only clean parts can be accurately
gauged and inspected for wear or damage.
There are many commercially available cleaners
that quickly remove grease, oil, and grime accu-
mulation from engine parts. If such a cleaner is
used, follow the manufacturer's instructions care-
fully. Make sure that all traces of the cleaner are
removed before the engine is reassembled and
placed in operation. Even small amounts of these
cleaners quickly break down the lubricating
properties of engine oils.
BASIC ENGINE TESTS
Crankcase Vacuum
A partial vacuum should be present in the crank-
case when engine is operating at normal tempera-
tures.

Crankcase vacuum check is best accomplished
with the "U" tube manometer.
Vacuum gauges, mercury and water manometers
are available commercially. However, a simple
"U" tube manometer can easily be constructed.
See "Section 1 Special Tools" for instructions.
An engine in good condition will have crankcase
vacuum of 15 inches (minimum) water column as
read on "U" tube water manometer, or 1.10 inches
(minimum) Hg as on mercury vacuum gauge.
Crankcase Vacuum Test
To test crankcase vacuum with a manometer:
1. Insert stopper in oil fill hole, leave other end of
tube open to atmosphere. Make sure shut-off
clamp is closed.
2. Start engine and run at high speed-3200 to
3600 rpm.
Compression Test
To check compression, remove spark plugs, insert
compression gauge in each spark plug hole, set the
throttle and choke to the wide open position, insure
that air intake and exhaust systems are not re-
SECTION 2
TROUBLESHOOTING
3. Release the clamp and note the water level in the
tube. The level in the engine side should be 15-
20" above the level in the open side. If there is no
vacuum or a positive pressure, check for the
following conditions:
NOTE: Clamp must be closed before stopping
engine.
a. Crankcase breather clogged or inoper-
ative. Disassemble breather, clean parts
thoroughly, reassemble, and recheck pressure.
b. Seals and/or gaskets leaking. Check for
proper sealing of crankcase.
c. Blow by or leaky valves. Confirm by test-
ing compression.
d. Exhaust restriction. Check for defective
muffler.
stricted, and motor engine using the starting
motor. Take several readings on both cylinders. A
difference in pressure reading between cylinders
in excess of 15%, or readings below 90 PSI can
indicate the following:
LOW COMPRESSION
Possible Cause Remedy
A. Cylinder head gasket blown. A. Remove head. check for flatness, replace gasket,
reinstall head, recheck compression. Locate and
correct the cause of initial failure.
B. Cylinder head warped or loose.
B. Remove head, check for flatness (see cylinder head
service).
Locate and correct the cause of initial failure.
c. Piston rings worn- blowby occurring. C. Recondition engine.
D. Valves leaking. D. Recondition valves and seats.
E. Excessive combustion deposits. E. Remove head and clean combustion deposits from
combustion chamber.
13

SECTION 3- AIR INTAKE SYSTEM
AIR CLEANER ASSEMBLY
Three types of air cleaner assemblies are used on
KT models: tear drop, square, and round.
Some
air cleaners may be equipped with a specially
designed "anti-icing" system. The anti-icing sys-
tem uses heat from the exhaust manifold to pre-
vent ice buildup in the carburetor and intake
manifold during cold weather operation.
The following guidelines apply to all air cleaner
assemblies:
1. Air cleaner base must be flat on gasket of air
intake elbow. Replace base if bent or cracked.
2. Gasket surfaces of element must be flat against
base and cover to seal effectively.
3.
Cover seal must be in place to reduce noise and
vibration of cover. Excess vibration can cause
stud hole in cover to enlarge, permitting dirt to
enter carburetor.
4. Wing nut must be finger tightened 1/2 to 1 full
turn after nut contacts cover-do not over-
tighten.
Refer to the instructions for the specific type of air
cleaner being serviced.
Tear Drop (Figure 3-1)
Disassembly
1. Remove the wing nut, cover, air cleaner cover
seal, and element.
2. Remove the breather hose and air intake tube
from air cleaner base.
3. Remove the screws securing base to intake
elbow. Lift base from intake elbow.
Assembly
1. Install air cleaner base and new base gasket on
elbow and secure with four 10-32 x 9/16" hex
washer head screws. Secure base to manifold
with hex nut on manifold stud.
2. Pull end of breather tube through 9/16" hole in
base making sure lips on end of tube seal
securely around hole in base.
NOTE: Early KT17 models have the breather
tube attached to intake elbow.
15
3. Slide airintake tube through hole in base so that
the end of tube extends into the blower housing.
The angled end of tube should face to the right
(long side-left, short side-right) when inserted
into blower housing (as seen from flywheel end).
Make sure lips on end of tube seal securely
around hole in base.
4. Place element on base.
5. Attach air cleaner cover seal to cover. Place
cover on base and secure with wing nut finger
tightened 1/2 to 1 full turn after nut contacts
cover-do not overtighten. (Seal on cover must
be in place and cover tightened to prevent
vibration.)
------- Wing Nut
,.g
Air Cleaner
.~---cover
~ :J Element
~ ..; .'-
~~
I~
! . I
I .
'\
------Base Screw
cg:r--Gasket
Air Intake
Tube
Figure 3-1. Tear Drop Air Cleaner Assembly

SECTION 3
AIR INTAKE SYSTEM
Fabricated Breather Hose
KT17 engines with the teardrop shape air cleaner
built prior to 1980 had a three-piece fabricated
breather hose (Figure 3-2) installed as original
equipment. Some engines show interference be-
tween the governor spring and this fabricated hose
resulting in the end of the hose being dislodged
from the air cleaner base plate.
When servicing a KT17 engine with a teardrop air
cleaner, note the breather hose, and if it is fabri-
cated, check the center portion around the hose
clamps for any indication (rubbing, abrasion, or
wear) of interference with the governor spring. If
interference is found, replace the fabricated hose
with a new one-piece molded hose (Figure 3-3).
Figure 3-2. Three-piece Fabricated
Breather Hose. (No longer used.)
Figure 3-3. One-piece Molded Hose.
Square {Figure 3-4)
Disassembly
7
1. Remove wing nuts, air cleaner cover, element
cover seals, element cover, and element (with
precleaner).
2. Remove the breather hose, air intake tube, and
air cleaner cover seal from air cleaner base.
3. Remove the screw securing air cleaner base to
intake manifold. Lift base from intake elbow.
Assembly
1. Install air cleaner base and new base gasket on
elbow and secure to intake manifold with hex
head screw.
2. Pull end of breather tube through 9/16" hole in
base making sure lips on end of tube seal
securely around hole in base.
16
3. Slide air intake tube through hole in base so
that end of tube extends into the blower hous-
ing. The angled end of tube should face to the
right (long side-left, short side-right) when
inserted into the blower housing (as seen from
the flywheel end). Make sure lips on end of tube
seal securely around hole in base.
4. Place element on base.
4a.
Elements with precleaners have a cover which
fits on top of the element. Place seals on studs
extending through top of cover.
5. Install air cleaner cover seal on base. Place
cover on base and secure with two wing nuts-
finger tightened 112 to 1 full turn after nuts
contact cover-do not overtighten. (Seal on
base must be in place and cover tightened to
prevent vibration.)
·.~ 0 Seals
/"~-~
e~-;;J Element
~ Cover
~=:,' Precleaner
~----Element
11---- Base Screw
w~Base
6
R___ Air Intake
r LT -Tube
~
a-----Gasket
_.-;'-)-,
R
'~ ----Intake Elbow
Figure 3-4. Square Air Cleaner Assembly.

Round (Figure 3-5)
Disassembly
1. Remove wing nut, air cleaner cover, element
cover seal, element cover, and element (with
precleaner).
2. Remove the breather hose from air cleaner base.
3. Remove the screws securing base to intake
elbow. Lift base from intake elbow.
Assembly
1. Install air cleaner base and new base gasket on
elbow and secure with four hex washer head
screws.
2. Pull end of breather tube through 9/16" hole in
base making sure lips on end of tube seal
securely around hole in base.
3. Install precleaner over element and place on
base.
4. Place element cover on element and the seal on
the stud extending through top of element cover.
5.
Secure air cleaner cover with wing nut-finger
tightened 1/2 to 1 full turn after nut contacts
cover-do not overtighten.
""-----Wing Nul
~~1
Air Cleaner
Cover
Element Cover
;'"''---seal
C)----~~~;;~nl
-~-~-
M tj-Precleaner
~~
Element
Base Screw
~Base
cQ)--Gasket
~Intake Elbow
~>-ft;;i/,"
lij -KJl
~
Figure 3-5. Round Air Cleaner Assembly
17
SECTION 3
AIR INTAKE SYSTEM
Anti-Icing System (Figure 3-6)
DTal d .............. Win~ Nut
~
(
~·~ · -~ Aor Cleaner
~ ~::- __ •. Cover
~ ~
~~Heater Plate
Element Cover
~-- _ \ \yl
Seal -L L
E~::~~-~ ~ ~
c ((i~~l em
;l_j ~~\~ I
Precleaner ~~eater Cover
Base/~ Element
Seal i
~~Base
~ Screw
~~Base
~~
Gasket
~Intake Elbow
'
Actual anti-icing system may vary, depending on
application.
Figure 3-6. Anti-Icing System
Disassembly
1. Remove wing nut, air cleaner cover, element
cover seal, element cover, element (with pre-
cleaner), and air cleaner base seal.
2. Remove the breather hose from air cleaner base.
3. Remove the screws securing air cleaner base to
intake elbow. Lift base from intake elbow.
4. Remove the air inlet heater cover, air inlet
heater, or heater plate, if so equipped.
Assembly
1. If so equipped, install inlet heater cover, or
heater plate over the exhaust outlet on the #2
side of crankcase.
2. Install new base gasket and air cleaner base to
intake elbow and secure with four hex washer
head screws.

SECTION 3
AIR INTAKE SYSTEM
3. Pull end of breather tube through 9/16" hole in
base. Make sure lips on end of tube seal securely
around hole in base.
4. Place air cleaner base seal on base. Install
precleaner over element and place on base.
5. Place elementcover on element. Slip the element
cover seal over the stud extending through top
of element cover.
6. Install air cleaner cover with air inlet duct
positioned for the correct season. Refer to the
decal affixed to the cover (see Figure 3· 7).
Position Air Cleaner As Shown Below
For Proper Engine Operation
ENGINE TOP VIEW
WINTER
BELOW 45" F (10" C)
SUMMER
ABOVE 45"F (10"C)
Figure 3·7. Typical Anti·Icing Air Cleaner
Cover Positions
For "winter" position-make sure air inlet duct
fits completely over heater cover or heater plate.
See Figure 3-8. To prevent unfiltered air from
Air Cleaner Cover
Heater Cover
Or
Heater Plate ""
Correct ~
entering engine, make sure air cleaner cover is
sealed around entire perimeter of base.
7. Install wing nut and finger tighten 1/2 to 1 full
turn after nut contactscover. Do not overtighten.
CAUTION: To prevent vapor-lock and to ensure
A proper engine operation, do not
.. operate engine during "summer"
seasons with air cleaner cover in
''winter'' position.
Precleaner
Some models are equipped with a precleaner.
Precleaners extend the useful life of the paper
element by trapping and retaining dust.
Precleaners should be washed and oiled every 25
operating hours, or more often under extremely
dirty,
dusty conditions, as follows:
1. Remove precleaner from air cleaner element
and wash precleaner in water with detergent.
2. Rinse thoroughly until all traces of detergent
are eliminated.
3. Squeeze away excess water and air dry. (Do not
wring precleaner.)
4. Soak in fresh, clean engine oil and squeeze out
excess oil.
5. Reinstall precleaner over air cleaner element.
Air Cleaner Cover
Figure 3-8. Installing Anti-Icing Air Inlet Duct
18

SECTION 4- FUEL SYSTEM &GOVERNOR
CARBURETOR
These engines are equipped with a side draft,
adjustable jet carburetor that was properly set at
the factory and should not have to be reset. If black
exhaust smoke is noted, check the air cleaner first
·an apparent "overrich" mixture can actually be
Condition
1. Black, sooty exhaust smoke, engine sluggish.
2. Engine misses and backfires at high speed.
3. Engine starts, sputters and dies under cold weather
starting.
4. Engine runs rough or stalls at idle speed.
To Adjust Carburetor:
Carburetor adjustments shouldbe made only after
engine has warmed up.
1. Stop engine, tum main fuel and idle fuel ad·
justing screws clockwise, until they bottom
lightly.
CAUTION: Adjusting screw ends taper to cri·
tical needle valves which will be
damaged if screws are turned in
forcefully.
2. Preliminary Settings-Main Fuel -(Models
KT17
and KT19) · turn main fuel adjusting
screw counterclockwise 2·112 turns from bot-
tom. (Model KT21) · turn main fuel adjusting
screw counterclockwise 3 turns from bottom.
Idle Fuel - (For all KT models) ·tum idle fuel
adjusting screw counterclockwise 1 to 1-1/4
turns from bottom.
3. Final Setting-Main Fuel - Start and run
engine at half-throttle for 5-10 minutes to warm
up. Turn main fuel adjusting screw clockwise
from
the preliminary setting until speed de·
creases and note position ofthe screw. Now turn
the screw counterclockwise · the engine speed
may first increase, then it will decrease as it is
turned. Note the position of the screw when
engine speed starts to decrease. Set the screw
midway between the two points noted.
19
due to a clogged air cleaner element. If element is
replaced and black smoke continues, or if other
conditions listed in the following table exist, adjust
the carburetor immediately. An incorrect setting
can lead to fouled spark plugs, overheating, ex·
cessive valve wear or other problems.
Possible Cause/Probable Remedy
1. Mixture too rich - readjust main fuel screw.
2. Mixture too lean - readjust main fuel screw.
3. Mixture too lean- turn main fuel adjustment 1/4 turn
counterclockwise.
4. Idle speed too low or improper idle adjustment -
readjust speed then idle fuel screw if needed.
4. Final Setting-Idle Fuel- Allow engine speed
to fall to idle or put throttle in Idle position.
Make adjustment using the same procedure as
Final Setting · Main Fuel in Step 3.
5. Idle Speed Setting-Run engine at half·
throttle for 5-10 minutes to warm up. Allow
engine speed to fall to idle, or put throttle in Idle
position. Set engine speed to 1200 RPM (± 75
RPM) by turning the idle speed screw clockwise
or counterclockwise.
Screw
Main
---Fuel
Screw
Figure 4·1. Carburetor Adjustments

SECTION 4
FUEL SYSTEM
AND GOVERNOR
CARBURETOR RECONDITIONING
Difficulties with fuel systems usually originate
from improper carburetor settings, or from dirt,
gum or varnish in carburetor components. The
necessity of cleaning will depend upon use and
operating conditions. To clean thoroughly, it will
be necessary to disassemble carburetor.
Cleaning Carburetor
All parts should be carefully cleaned using a
carburetor cleaner (such as acetone). Followclean·
er manufacturer's warnings and instructions on
its proper and safe use.
CAUTION: Carburetor should not be submersed
h in cleaner or solvent, it may damage
8 fiber and rubber seals.
Be sure all deposits are removed from bore, es-
pecially where throttle plate seats in casting. Blow
out all passages with compressed air. Replace all
worn and damaged parts. Always use new gaskets.
Carburetor repair kits are available from your
Kohler parts supplier. Kits include a bowl retaining
screw gasket, bowl ring gasket, float pin, bowl
baffle gasket, and fuel inlet needle and seat.
Disassembly of Carburetor
(see Figure 4-2 for location of parts)
WARNING: Disconnect and ground spark plug
leads to eliminate electrical spark.
When disconnecting fuel lines be sure
to wipe up any spilled fuel and make
surenosources of heat,flame or sparks
are near, as these can cause gasoline
fumes to explode.
1. Shut off fuel source.
2. Disconnect breather hose from carburetor in-
take elbow or from air cleaner base. (See Figure
8-39).
3. Remove air cleaner assembly.
4. Disconnect fuel line, governor linkage and
choke linkage from carburetor.
5. Disconn!'ct carburetor (with elbow attached)
from manifold by removing two nuts. Separate
carburetor from elbow by removing three
screws.
6. Remove bowl retaining screw and bowl. (Bowl
may still contain gasoline-handle carefully.)
7. Remove float pin, float, fuel inlet needle and
seat. Check float for dents and leaks, also
check for wear on float tabs or float hinge.
8. Remove baffle gasket and bowl gasket.
20
Idle Speed
Screw
),~~-:
Idle Fuel
Adjusting
I
Main Fuel
-------
Adjusting
Screw
Screw -~
r-- c:::)----::.~~.
(J
~--Baffle
Float
Hinge
Fuel
Inlet
Needle
~
and sey _;:.;;;;:;:;;;:,::_
\
Float
Bowl Retaining-
Screw
Float Pin
·--Bowl Retaining
Screw Gasket
Figure 4·2. Side Draft Carburetor- Exploded View
9. Remove idle fuel adjusting screw, main fuel
adjusting screw and springs.
10. If the throttle and choke shafts are worn, a
repair kit is available. Refer to the Parts
Manual for the part number of this kit.
Assembly of Carburetor
1. With carburetor casting inverted, install fuel
inlet seat. Torque seat to 35 in. lbs.
Install inlet needle, float, and float pin.
NOTE: Floats in current production carbure-
tors have two tabs on the float hinge. Bend tab