KOHLER
GENERATORS
ENGINE
SERVICE
MANUAL -
.
SECTION
E-7
MODELS: ‘L600, 1654
.
CONTENTS’
SUBJECT
SECTION-PAGE ! SUBJECT -
SECTION-PAGE
GENERAL
LU6RICAlION
Prestart Check List .
1.3
Gen. Specifications . 7.4
Service Schedule . . . .
1.4
Oil Requirements . . . .
2.1
Oil Pressure . . . . . . . .
2.1
i COOLING
I
I
I
Radi ator Systems . . .
6.1
Anti-Freeze . . . . . . . .
6.1
Fan Belts . . . . . . . . . .
6.2
. . . . . 6.3
Marine Cool i ng
Oil Filler Cap
......
2.1
Oil Filters
1 GOVERNOR Governor Adjustments
7. I
.........
2.2 -
Dry Air Cleaner
.....
3.1
......
8.1
Oil Bath Cleaner
....
3.2
1 GENERAL SERVICES Cylinder Head
Valves
.............
Flame Arrestor
I
8.1
......
3.2
I
Compress i on
........
8.2
AIR INTAKE
FUEL
Gasol ine Carburetors
4.1
t
Fuel Pump . . . . . . . . . . .
4.4
,
Automatic Chokes . . . .
4.5
1 RECONDITIONING
Inspection-Analysis 9.1
Gas Carburetors
4.6
I
Disassembly . . . . . . . .
9.3
. . . . .
Gas Regu 1 ators
. . . . . .
4.7
I
Reconditioning
. . . . . 9.6
.
Re-assembly
. . . . . . . .
9.11
~~~ ~~
.
IGNITION
Spark Plugs
. . . . . . . . .
5.1
Magneto Sewi ce
. . . . .
5.2
Magneto Installation 5.3
Ignition Timing . . . . .
5.4
I
I
1 SPECIFICATIONS
Clearances-Fi ts
. . . . 70.1
I
.
Ignition Specs. . . . . 10.2
t
Torque Specs.
. . ...*
10.2
KOHLER CO. KOHLER, WISCONSIN 53044
7 QUART CAPACITY
(APPROX.) RADIATGR
/--PRESSURE CAP
THERMOSTAT HOUSING
-FAN-BELT
-AUTOMATIC CHOKE
.
I
.
. .
.
/
/
f
f
1
IrDJUSTABLE 4
~LLEY(BELT
YENSION)
FAN BEFT-
FUEL PUMP
GENERATOR
END COVER
OIL DRAIN-
OIL LEVEL
\
LAIR CLEANER
DIPSTICK
(OIL BATH TYPE) ,
FIGURE 1-7
-M CARBURETOR SIDE VIEW - TYPICAL RADIATOR COOLED PLANT WITH L600 ENGINE
OIL FILLER -
MAGNETO
WATER PUMl
3
-7
7.5 QUART CAPACITY
#I______ . -1--a-a-
BREATHER CAP-----r
(STANDARD) c-i
I
(AWKOX. ] RAPIATOR~-/
/
CONTROLLER
\
\
V IBRQ MOUNT
.
COOLANT
-DRAIN
OIL FILTER
(OPTION) PAD
FIGURE 1-2
-- MAGNETO SIDE VIEW - TYPICAL RADIATOR COOLED PLANT WITH L654 ENGINE
12
.
a
.
. PRESTART CHECKLIST
Lubricating Oil: Check crankcase oil level on dipstickRefer to Page 2. 1 for oil specifications.
fill as needed to bring level up to Full mark.
Cooling System:
manifold, then add clean fresh water until level is just below overflow tube.
required for initial fill on radiator models,
temperatures are anticipated,
water cooled models, make sure cooling system is properly installed to insure sufficient coolant.
Direct systems are of the open type and cannot therefore be protected with antifreeze.
Air Cleaner:
bowl. Use same weight and grade
no prestart service except to make
On closed type cooling systems,
add antifreeze to radiator cooled and heat exchanger models.
If oil bath type used,
unfas
of oil
sure
5 to 57 f/2 quarts for heat exchanger models.
ten bowl retaining clamp and add oil to level marking (bead) in
as used in engine.
elements are in place so that unfiltered air cannot enter engine.
remove radiator cap or cap on water cooled exhaust
Dry type and flame arrestor units require
CARBURETOR
7 to 7-l/2 quarts are
If freezing
On direct
..-.w..v..ww
FIGURE 1-3 -- CARBURETOR SIDE VIEW - TYPICAL RADIATOR COOLED PLANT WITH L654 ENGINE
g-Z g$iF@%&%ZE~Z~ gasoline.
before initial start up. On gas fueled plants,
Refer to Fuel Section for typical arrangement and preliminary adjustments.
Battery: These elect&c plants feature exciter cranking which offers higher cranking speeds for
more positive starting.
cranks the engine during starting then is autotitically switched back to its generating function after the
e’ngine starts.
A 24 volt battery is required for DC generator models and a 12 volt battery for AC generator
models.
tery to the P terminal of controller and the negative (-) battery terminal to the N terminal on controller.
(Stamped on base of controller near starting solenoid or C coil. )
or use two 67volt batteries to create a difference in voltage between leads Ll and L2.
both leads have to be connected to the battery positive (t) terminal, and cranking relays in L2 will not
operate when the voltage is the same.
L3 to the center tap and L2 to ground which is battery negative (0).
32 volt cranking is available for marine models.
‘ITo start three-wire automatic start plants,
When battery current is applied to the generator, it functions as a motor and
connect lines
make sure system is properly hooked up before starting.
With the center tap, lead Ll is connected to battery + terminal,
from storage tank to the fuel pump.
Use priming lever on fuel pump to prime system
Connect the positive (t) terminal of the bat-
it will be necessary to center tap the 120volt battery
l
13
Fill tank
Without this,
SERVICE
Kohler Model L600 and t654 engines are covered in this Service Manual.
4-stroke cycle’ gas or gasoline fueled engines.
Both are liquid cooled,
out the manual.
Differences are called out whenever significant through-
Some of the general specifications are listed below for convenience--refer to the
appropriate section for more specific details.
SPECIFICATION
I
L600 I
L654
BORE X STROKE
.*~**********o****o***................
DISPLACEMENT (CUBIC INCH)
l o.**.*.**.**.***.**.....
LUBE OIL CAPACITY (U.S. STD.)
l o**o***************b
I
2-5/8 x 3"
65
5 Quarts
7.5 Quarts
5 Quarts
14mn
.025" *
018
II
.
018
22. ft." 1 bs.
.Ol5"
2-5/8 x 2-3/4"
59.4
4 Quarts
7.0 Quarts
5 Quarts
14mn
.025"
018
II
.
078
22.ft.Y;bs.
.015"
RADIATOR CAPACITY (U.S. STD.>
l *.**.****.*******.**
MARINE (CLOSED) COOLING CAPACITY
l **********o*******
SPARK PtUG SIZE (USE J-8 OR EQUIVALENT)
l **********
SPARK PLUG GAP (STD. PLUG - GASOLINE) i............
SPARK PLUG GAP (STD. PLUG - GAS)
l ****e************
SPARK PLUG GAP (SHIELDED PLUGS)
l ******************
PLUG TIGHTENING TORQUE
l ***o******************o****e
BREAKER POINT GAP . (INSIDE MAGNETO)
l ***************
HOSE
- THERM0
HOSE
PUMP TO ADAPTER
INLET (TOP)
TO TOP OF
FOLD
HSG.
MAN1
ADAPT
HOSE - ADAPTER
TO EXHAUST
MIXER
WATER PUMP .
SEA
WATER
II /u
INLET
EXHAUST
II
YIXER
WATER COOLED
EXHAUST OUTLET
FOR l-3/4" I.D.
FIGURE 1-4 -- CARBURETOR SIDE VIEW - TYPICAL MARINE GENERATOR SET
SERVICE SCHEDULE
PERFORM SERVICE AT INTERVALS IMIICATED (X)
EVERY
I
EVERY
'
100 HOtlRS
200 HOURS
(OR 6 MONTHS)
(OR YEARLY)
Check oil level
------------------------- ----
X
Check coolant level
--------------------- ----
X
Check condition of compartment ----------
----X
Check valve
clearance ------------------Check breaker points
Check ignition timing
Clean crankcase breather ----------------
Check generator brushes -----------------
Change oil ------------------------------
a--------- ------- X
Check fan belt and tension -------------
---------- ------- X
Check air
intake silencer ---------------
----------
------- X
Check spark plugs
-----------------------
---------- ---------------
Check electrolyte level in battery ----i-
----------
---------------
Check electrical
connections ------------
---------- ---------------
NOTE:
Intervak stated are for norm2 operating co7uiitims--perform servCces more fretpentty under
servere conditions.
.
14
8
LUBRICATION
LUBRICATING OIL -
TO be on the safe side, check oil in engine crankcase before each start to insure that the level
is between the L and F marks on dipstick.
Do not operate plant if level exceeds the *‘F1’ mark or if
below **L*l marnove oil filler-breather cap and add oil here.
Use only 03s meeting the require-
ments of the American Petroleum Institutes (API) Service classification SC.
Oils with this classifica-
tion are detergent type oils.
The classification is usually stamped or printed on the oil cans.
SERVICE Use SAE 30 weight for temperatures above 30* F.
--~~~~~~~~~~~~~~~~~~~~~-~~~~~~~~~~~~~~~~~~-
SC
Use SAE 10 weight for temperatures below 30’ F.
On a new plant,
change oil after the first 5 hours of operation and thereafter at 50 hour
every 6 months--whichever occurs first),
Change oil more frequently if plant -operated
under extremely dusty or dirty conditions.
Whenever possible,
drain oil while hot as it will flow more
freely and carry away a greater amount of contamination.
.
20 PSI NORMAL
ACORN NUT
(NOT USED ON
SOME MODELS)
PRESSURE ADJUSTING SCREW
.
FIGURE 2-l
-- NORMAL OIL PRESSURE AND ADJUSTMENT
OIL PRESSURE ADJUSTMENT
.
Oil Pressure: After the engine has been thoroughly warme d up and is operating
with proper weight of
011 in crankcase, the oil pressure should be about 20 psi.
An external oil press ure adjusting screw is
provided on the crankcase just below and to the rear of the carburetor.
Lf norm al operating pressure
is lower than 20 psi,
remove acorn nut, loosen lock nut then turn screw until pressure is correct.
Secure lock nut at new setting and reinstall protective acorn nut. When engine is cold, pressure may
be as high as 50 -
60 psi but should gradually return to about 20 psi as the engine warms up.
OIL FILLER - BREATHER CAP
After about every fourth oil change (200 hours),
service oil filler-breather cap. DO this more
of&n under dusty, dirty conditions.
A clogged breather can lead to build up of abnormal crankcase
pressures and result in l’eakage around seals, gaskets, etc.
Service breather by washing in solvent such as kerosene --swish element in solvent to dislodge
dirt.
After cleaning,
allow a few moments for it to drip dry then apply light amount of oil to the mesh
eleme’nt.
Use same weight and grade of oil as used in engine.
Always make sure cap is in place before
placing engine in operation.
.
- FILLER -
l
CARTRIDGE
TYPE
RUBBER
SEAL
\
MOUNTING GASKET
(DON’T REVERSE
POSITION TO
BLOCK OIL HOLES)
FIGURE 2-2 -- OIL FILLER - BREATHER
FIGURE 2-3 -- OPTIONAL OIL FILTER
OIL FILTER - OPTION
.
If your engine is equipped with the
0p tional oil
filter,
change the filter cartridge after each 200
hours of operation. This should be done
at the same time
change. Wrap rags
the oil 1s drained during every fourth oil
around the base and
use pan to c atch a ny oil trapped in the cartridge. Twist cartridge off by hand- turn in counterclockwise direction to remove.
engine oil isreplen,ished and engine is again placed in operation,
l&d tighten new cartridge--‘after
leakage--retighten element as needed to stop leaks.
check area around filter for signs of
Doa? use substitute cartridge elements for replace-
ment-use only genuine Kohler parts.
If the engine does not have a filter but is operating in high dust, dirt areas, the oil filter feature
can be quickly added.
Simply remove the two plugs from the filter mounting, position a new gasket on
the pad (make sure holes in gasket match oil holes) and secure the filter assembly with 4 capscrews.
*
3
22
l
. .
.
AIR INTAKE
I
AIR CLEANER SERVICE .
An air cleaner must be maintained in proper condition to insure satisfactory performance and
prolonged engine life. Operating with an !‘overrich” fuel mixture caused by a poorly serviced, clogged
air cleaner leads to formation of harmful sludge deposits.
An inadequate element or improperly
installed air cleaner permits entrance of dirt which can wear out piston rings in a very short time.
The service intervals stited for air cleaners are for good clean conditions--service cleaners more
frequently under dusty or dirty conditions (even daily,
if extreme conditions warrant this). Dry and oil
bath type cleaners are used
--carefully follow instructions for type in use. A flame arrestor type
cleaner is used on many marine models.
DRY TYPE AIR CLEANER
Replace-element after 100-200 hours if operating under gdod clean air conditions--sooner in dusty,
dirty conditions. Use only genuine kohlerreplacement elements of correct part number.
Every 50 hours (or 3 months), remove element and lightly tap rubber rim against flat surface to
dislodge any loose dust from surface.
Replace element if it has too many dark spots or extensive dark
area as this indicates dirt trapped in the filter material. Do not wash dry element in any liquid or
attempt to clean element with air hose as this will ruin or rupture the paper fiber material.
When
handling element, avoid crushing material or bending element as this co&d allow unfiltered air to
enter the engine
--note a’ir flow shown in the figure below.
When installing a new or serviced element, make sure rubber gasket surfaces are flat against the
filter base and cover
--secure wing nut (with washer in place when used) finger tight--washer is not
required with plastic type wing nuts.
.
~~ -~
FIGURE 3-7
-- CIRCULATION THRU DRY AIR CLEANER
(WASHER NOT
REQUIRED
UNDER PLASTIC
TYPE)
AIR
BASE
FIGURE 3-2
,- TYPICAL DRY TYPE AIR CLEANER
1 cup-
I
’ .
I
I
OIL
LEVEL
BEAD
I
FIGURE 3-3
-- OIL BATH TYPE AIR CLEANERS
I
I
OIL BATH TYPE AIR CLEANERS
There are several different types of oil bath air cleaners in use; however, the same general ser-
vice recommendations apply to all.
bowl, clean out dirty oil, fill to level indicated with same grade of oil used inengine or, with see thru
‘SAF-T-VUP type use SAE 40 in summer, SAE 20 in winter.
Every 100 hours (or more often under severe conditions) service the filter element. On types
shown above, as A & B, remove bowl and breather hose then disconnect air cleaner with elbow attached
at the
c’arburetor
in solvent such as kerosene,
in the foregoing.
--do not attempt to separate cleaner from the elbow.
then allow it to drip dry before reinstalling.
After every 50 hours operation (or every third month) remove oil
On all types, swish element unit
Service oil bowl as described
FLAME ARRESTOR (NiARlNE MODELS)
Marine Models use an approved flame arrestor which also serves as an air cleaner to a certain
degree.
encountered in marine applications.
swish element in a cleaning solvent that does not leave a film,
ing on the engine.
shown below to insure that the unit can function as a flame arrestor.
This unit does not require regular service because of the clean operating conditions normally
When the element starts to appear dirty, disassemble the unit and
Keep the element dry--do not oil.
Make sure parts are reassembled exactly as
then allow it to drip dry before reinstall-
FIGURE 3-4 --
FLAME ARRESTOR FOR MARINE MODELS
32
l
COVER
FUEL SYSTEMS
GENERAL
.
Carburetor Adjustment:
The following procedure covers the initial adjustment of both. up draft and side
draft type carburetors.
An idle adjusting needle is provided on the horizontal carburetor even though
engine operates at idle speed only for a brief moment as it comes up to speed after it is started or when
it slows after being shut down-
the idle adjustment is therefore not critical and can be permanently set
at 2 turns open. The up draft type carburetor does not have an idle adjustment.
CARBURETORS - GASOLINE
Carburetors are adjusted in the factory and readjustment is not normally needed unless plant is
operated at a much higher altitude or if carburetor problems develop after extended usage.
If engine
misses and backfires,
this could indicate carburetor is see too lean.
If black, sooty exhaust smoke is .
noted and engine is sluggish,
the fuel mixture is probably set too rich.
Do not neglect carburetor problems for continued operation with improperly adjusted or dirty carburetor can result in overheating,
fouling of spark plugs,
excessive valve wear and other problems.
HIGH SPEED
I- THROTTLE LINKAGE
STOP
FUEL
INLET
l-1/2 TURNS OPEN
MAIN FUEL 2-l/2 TURNS OPEN
INIir
FUEL
INLET
IDLE FUEL
-2 TURNS
FIGURE 4-7
-- TYPICAL UPDRAFT’ CARBURETOR
FIGURE 4-2 -- TYPICAL SIDEDRAFT CARBURETOR
STEP 1 -
STEP 2 -
STEP 3 -
STEP 4-0
Stop engine and carefully turn Main Fuel adjustment all the way in (clockwise) until the needle
bottoms lightly-
do not force as this will damage needle or seat.
For preliminary adjustment,
turn Main Fuel adjustment out (counterclockwise direction)
2-l/2 turns on side draft carburetor or l-1/2 turns open on up draft carburetor.
Start engine and allow it to warm up to normal operating temperatures.
Place engine under
normal load when- making final adjustment.
For final adjustment,
move Main Fuel needle in until engine starts to slow down from too lean
a mixture (note position),
then back out until speed increases--continue turning richer until
speed again starts to drop from overrich setting then turn needle back in until it is positioned
about halfway between lean and overrich settings.
Carburetor Reconditioning: If readjustment does not remedy problems attributed to carburetor, car-
buretor should be dzsassembled and reconditioned. Always use carburetor repair kit for best recon-
ditioning results.
After carburetor is completely disassembled, all metal parts should be cleaned in a
solvent such as alcohol or aketone or commercial cleaner which readily remove gum and carbon deposits.
Blow out all passages with compressed air and replace all gaskets and worn parts. Repair kits contain
essential parts.
Disassembly and reassembly of carburetors is accomplished as follows:
.
41 a
Disassembly of Carburetor - Up Draft
1.
After removing carburetor from engine,
remove 4 capscrews and separate throttle body (includes
float) from lower carburetor body. .
2.
Remove float pin,
float and body gasket.
Remove fuel inlet needle. Check needle for damage and
float ior dents, leakage or excessive wear on lever or in hinged area.
3. Remove throttle plate retaining screw (and lock washer) then slip plate out of slot in shaft. Slide
throttle shaft out of body.
Inspect bushing and shaft -- unfiltered air could enter in this area if
worn.
4.
Remove main fuel needle -
inspect for wear or damage.
clean venturi and fuel bowl areas.
Blow out main fuel nozzle, thoroughly
.
5.
Do not remove choke plate or choke shaft uhless loose or damaged. Further disassembly of lower
body is not normally necessary.
.
.
Reassembly of Carburetor - Up Draft
Reassembly is essentially the reverse of the disassembly procedure. Special instructions are
needed, however, to properly set the level of float before throttle body is reinstalled to carburetor body.
Float: Level; Turn throttle body upside down,
install new gasket and fuel inlet needle then position float
and insert float pin.
With float lever resting on inlet needle, measure distance between gasket and
bottom of float at free end.
The distance should .be S/16*’ - if adjustment is needed, carefully bend
float lever to attain proper level.
After carburetor is reinstalled on engine, recheck for proper level
by removing fuel level plug -
if properly s&t, fuel level should be just below this hole.
THROTfLE PLATE
0
THROTTLE
-
SHAFT
.
.
GASKET, UPQER BODY
CARBURETOR,
UPPER BODY
.
VENTURI
GASKET s
FLOAT (GASOLINE)
ILE & SEAT
SHUTTER (PLATE)
.
CHOKE SHAFT
CARBURETOR,
LOWER BODY
1.
MAIN FUEL ADJUSTING NEEDLE
FIGURE 4-3 -- _ EXPLODED VIEM - TYPICAL UPDRAFT CARBURETOR
.
42
l
CARBURETOR BODY
BOGI RING GASKET
-FUEL BOWL
BAFFLE
-
\ BOWL RETAINER
MAIN FUEL
. _ ____ - ---
.
NEEDLE & SEAT
WGY
#,/SCREW & GASKET
SHAFT & PLATE
1 FUEL FLOAT
FIGURE 4-4 --
EXPLODED VIEW -
TYPICAL
SIDEDRAn CARBURETOR
Disassembly of Carburetor - Side Draft
.
.
1.
Remove carburetor from engine.
2.
Remove bowl nut, gasket and bowl.
When carburetor has bowl drain, remove drain spring, spacer
(when’used) plug and’gasket from inside of bowl.
.
.
3.
Remove float pin,
float, needle and needle seat. Check float for dents, leaks and wear on float
lip or in float pin holes.
4. Remove bowl ring gasket.
5.
Remove idle fuel adjusting needle,
main fuel adjusting needle and springs.
6.
Do not remove choke and throttle plates and shafts.
If these parts are worn, replace carburetor
assembly.
Assemblv of Carburetor - Side Draft
1.
Install needle seat, needle, float and float pin.
.
2.
Set float level.
With carburetor casting inverted and float resting lightly against needle in its
seat, there should be 11/641V plus or minus l/32 of an inch clearance between machined surface
of casting and free end of float (side opposite needle seat). l
3.
Adjust by bending lip of float with small screwdriver.
.
.
.
4.
Install new bowl ring gasket,
new bowl nut gasket (when required) and bowl nut.
Tighten securely
after making sure bowl is centered on gasket.
5.
Install main fuel adjustment needle.
Turn in until needle seats in nozzle and back out two turns.
6.
Install idle fuel adjustment needle.
Back out approximately l-1/2 turns after seating lightly against
jet.
CAUTION: DO NOT USE: FORCE ON ADJUSTMENT NEEDLES.
.
.
GASOLINE FUEL PUMP
The fuel pump does not require regular service but may have to be rebuilt to restore normal
efficiency after extended hours of operation.
If your engine falters or stumbles each time the load is
increased, this may be due to a worn-out fuel pump.
The repair kit listed in the parts manual for this
pump includes all parts necessary to restore normal efficiency of the fuel pump. Remove fuel pump
from engine and rebuild as follows:
DISASSEMBLY
_
STEP 1: Scribe matching marks .on fuel head and pump body before disassembly.
STEP 2:
Remove cover capscrew and cover. Discard cover gasket.
STEP 3: Remove 6 screws from around perimeter of fuel head,
then separate head from body.
Note direction of valves then press old fuel valves out of fuel head--discard valves
and valve gaskets.
GASKET-/
m
es
PUMP
53
COVER
: DIAPHRAGM
I
-f
!
3
a
I
m
'VALVE i
SEAL-
x
L-ARM SPRING
v?
PUMP BODYa
n
NOTE: Primer lever is spring
‘r&d to DUZZ back into
position At to engine-
if it sticks in the atended
position, t?& diaphmgm cm-
not operate to pump fbeZ.
Make su2-w teverretums to
proper posCtion.
.
FIGURE 4-5
-- FUEL PUMP EXPLODED AND
CUTAWAY VIEWS
STEP 4: To disassemble pump body, first insert screw driver blade into coils of pump arm
spring and compress spring to remove.
Next com.press the diaphragm spring then
lift the link to disconriect and remove the diaphragm and oil seal--discard these
parts. Push pin out to release pump arm and link to complete disassembly.
RECONDITIONING
Wash fuel head, body and cover in gasoline and clean with stiff bristle brush.
Make sure all
traces of gasket material is removed from surfaces.
Recondition components as follows:
FUEL HEAD: Position new valve gaskets then press new valves from kit into place. Position new
cover gasket on head,
then install cover and tighten capscrew.
PUMP BODY: Position link and pump arm,
the- install and stake new pin. Place new oil seal and
spring then install n&w diaphragm assembly and hook it to the arm link.
Replace pump arm spring.
Don’t reassemble the body to the fuel head at this time.
/.- *
INSTALLATION ON ENGINE
To attain proper operation of the rebuilt pump be sure to follow this reinstallation procedure.
.
STEP 1:
Use a new pump body gasket then reinstall pump body assembly on engine. Turn
engine until diaphragm is flat against the pump body then position fuel head (with
scribe marks aligned), then temporarily tighten the six screws only about three
turns--again turn the engine until the diaphragm pulls down into the body then
securely tighten the six screws.
After this is done,
reconnect fuel lines to com-
plete the reinstallation.
.
44
0
.
INSERT #43 DRILL
IN NOTCH
LOOSEN
CLAMP BOLT
TO AD&
CONTROLLER LEAD(S)-
A?V An\ - ---- -- -_- -- ,-,
*(SIkLE OR DOUBLE
WmE UNIT USED--
NOT INZZRC'KAIVGEABLE)
LEVER UP TO
#EASE CHOKE
UP -
INCREASE
DOWN DECREASE
FOR ADJUSTING
KE CROSS SHAFT
BASE OF CHOKE BODY
-_a._-- 1 m .__..__A. _ .AA ..L. -_a _L - - ~ -
FIGURE 4-6 -- MANIFOLD MOUNTED TYPE AUTOMATIC CHOKE
AUTOMATIC CHOKES
.
Two different electric
- thermostatic type automatic chokes are used. One type is an integral
part of the carburetor while the other type is mounted on the exhaust manifold and connected through
external linkage to the choke plate in carburetor.
The electrical leads to the choke are connected so
that current flows to the thermostatic element only when the ignition is turned on.
Tension of the
thermostatic spring is set to atlow full choke at starting.
On manifold type, heat from the manifold con-
trols tension of the thermostat spring which causes the choke plate to be gradually returned to the open
position as the engine warms up.
On carburetor units,
vacuum from intake manifold pulls the choke
open. Chokes are adjusted in the factory, however,
slight readjustment may be necessary initially to
account for different starting conditions.
Adjust chokes as foUows:
Carburetor Unit:
Choke unit is set for average conditions.
To readjust,
loosen three screws on outside
of cover plate then shift cover in clockwise direction (arrow) for richer setting or in counterclockwise
direction for leaner setting.
Tighten cover screws after final adjustment.
Exhaust Manifold Mounted Unit:
Remove air cleaner from carburetor to observe position of choke plate.
aoke adjustment must be made on cold engine.
If starting in extreme cold, choke should be in full
closed position before engine is started.
A lesser degree of choking is needed in milder temperatures.
.
If adjustment is needed, proceed as follows:
7.
Move choke.arm until hole in brass shaft lines up with slot in bearings.
2. Insert #43 dri 11 ( l 089) and push al 1 the way down to engine manifold
to engage in notch in base of choke unit.
3. Loosen clamp bolt on choke lever, push arm upward to move choke plate toward closed
* position.
After desired position is attained, tighten clamp bolt then remove dri'll.
SPRiNG
PLACEMENT
WRONG
RI &IT
I
I
1.-~~~~~~~-~~~~-----~~
INITIAL SETTING
ON CENTER NOTCH
INTAKE MAN I FOLD
-- _ -
FIGURE 4-7 --
_ _-
CARBURETOR MOUNTED TYPE AUTOMATIC CHOKE
_
GAS SYSTEMS l
Natural gas supplied from main transmission line is normally received at pressures not greater
than 51) pounds per square inch (psi) while with LPG, which is Butane or Propane or usually a mixture
of the two gases,
the pressure may go as high as 180-200 psi depending on the mix ratio and tempera-
ture. To be used by the engine the pressure must be reduced to.ounce values.
The reduction is nor- s
mally accomplished in two stages by a primary regulator which reduc line pressures to about 6 ounces
per square inch and a secondary low pressure regulator which further reduces the pressure in accordance with engine demand. The primary regulator is often furnished by the fuel supplier. The fuel
supplier should also insure that gas pressure is sufficient to operate the primary regulator.
If pressure
drops too low, the regulator may not function at all. - While propane, for example, tends to maintain
some vaporizing pressure even at temperatures down to -20’ F. , butane returns to liquid state and
offers little or no vapor pressure when the temperature drops to freezing or 32O F. For this ‘reason,
fuel suppliers usually supply LPG of higher butane content in hot weather but will alter this to a higher
percentage of propane during cold weather. If this ratio is not changed,
starting and operating difficul-
ties may be encountered in cold weather.
Straight gas and combination gas/gasoline systems are used.
The combination system uses a gas
mixer or adapter attached to a standard gasoline carburetor.
and regulators are discussed in the following.
Some common carburetors, adapters,
GAS CARBURETORS - ADAPTERS
In a venturi type carburetor,
the gas nozzle is located at the point of greatest pressure drop inside
the venturi.
This creates a suction within that nozzle that varies with changing rate of air flow and
causes a greater volume of gas to be metered at heavier loads and a lower volume at lighter engine load.
The throttle valve regulates the rate of air flow through the carburetor.
this valve is wide open and offers ‘little restriction to air flow.
When an engine is at top speed,
Closing the throttle causes a decrease
in air flow and lowers engine speed and power.
As the valve closes, it reduces pressure through the
venturi and past the fuel nozzle.
On engines with the gasoline carburetor,
an adapter with venturi is installed between the carbure-
tor and air cleaner.
The adapter consists of a gas jet and venturi.
Accurdte metering of the gas is
accomplished by load and starting or idle adjustment screws in the body of the adapter.
Most gas carburetors are simple devices having only one moving part--the throttle shaft and
plate (or butterfly valve as it is sometimes called).
Because of this, they should require very little
attention and readjustment should seldom be needed.
If needles wear out or venturi is damaged, these
I
IDLE FUEL
BREATHER.
TUBE TO
VALVE COVER
IDLE
SPEED
ADJUSTMENT
JdAIN FUEL
.
SECONDARY
GAS REGULATOR
(MODEL UN)
-=--ii& OIL BATH
I
TYPE AIR
CLEANER
(3/4” NPT
FROM PRIMARY REGULATOR)
.
FIGURE 4-8 --
TYPICAL STRAIGHT GAS FUEL SYSTEM
46
l
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