Wisconsin AFH-AGH-AHH User manual

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HARLEY SA L ES COMPANY
DISTRIBUTOR
WISCONSIN .1ir-rooleJ ENGINES
TULSA • HOUSTON • WICHiTA
INSTRUCTION BOOK AND PARTS liST
MODEL AFH-AGH-AHH
ISSUE MM 247-A
WORLD'S LARGEST BUILDERS O F HEAVY DUTY AIR COOLED ENGINES

I
IMPORTANT
STARTING AND OPERATION OF NEW ENGINES
Careful breaking in of a n ew eng ine will greatly increase its life and result
in trouble-free op e ration . A factory test is not sufficient to establish the
poli shed bearing surfac (!S , whicb ar e so necessary to the proper perform·
ance and long life of an en gine. Ne i ther is there a quick way to force the
establis hment of good beari ng surfaces. These can only be obtained by
running a new engine car ef ull y and under reduced speeds and loads for
a sh o rt time, as follows:
First,
be s ure the engin e is fi ll ed to the proper level with a good quality
of
engin e oil, s ec " Grade of Oil" ch art.
Before a ne w engine is put to its r eg ular work, the engine should be oper-
ated at low jdle sp e ed (10 00 to 1200 R.P.M.) for one half hour, without
lo ad . The R.P.M. s hould then be increased to engine operating speed,
still with o ut load, for an ad diti on al two hours.
If at all po ssible, operat e the engi ne at light loads for a period totaling
about eight hour s, before ma ximum lo ad is applied . This will greatly in-
crease engine life.
The variou s bearing sur faces in a new engin e have not been glazed, as they
will
be with c ontinued op era tion, and it is in this period of "running in,"
that special care must be e xe rcised, oth erw ise the highly desired glaze will
never be obtained. A new be arin g sur face that has once been damaged by
carelessness w
ill be ruin ed f ore ver.
THEREFORE READ INSTRUCTIONS CAREFULLY
A cop y of this manual is sene ou t wit h each engine. All poinrs of opera-
tion and maintenance have been c ov ered as carefully as possible but if
fu~;tber informacion is re qu ired, i nq uiries se nt to the factory will receive
pr
ompt a.tten ci oo.
Wh en writing the facLOr y AL \"qAY S GIVE 'tHE MODEL AND SERIAL
NUMBER of engine refer te d to.
Extr a c opi es of this manu al are $ 1. 00 each.
WISCONSIN MOT OR CORPORATION
MILWAUKEE 46, WISCONSIN

•
BOOK OF INS TRUCTIONS
WISC
ONSIN
SIN GLE CYLI NDER ENGINES
M ODEL ADH
23 h" Bore 3'h" Stroke
19 .3 cu. in. Displacement
MODELS AE ~ AEH, AEHS
3" Bor~ r;r!T Stroke
23 cu. in. Displacement
M ODEL AF H
3'h" Bore 4" Stroke
33.2 cu. in. Displace ment
MODEL AGH
3 Y2" Bore 4" Stroke
38.5 cu. in. Di sp lacement
MODEL A HH
3%" Bor e 4" Stroke
41.3 cu. in. Displacement
Not e: leHer ··o·· Suffixed to tho Enalno Model DesiQnotea tha f t he EnQlne ha• Stellite
Exhaust Valve and St ellite Exhou11 Valve Seat ln•ert.
I

INDEX
PAGE
En gine Models................... .. ................... .. .... .. ......
Illustration of Engines .. .. . .. . .. .............................. 3-4
Sectional Drawing .............................................. ..
General Information and Design ...................... ..
Start ing and Operating Instructions ................ ..
Horse Power .............. .. ......,............................... ..
5
6
7
6
Safety Precautions ............................................ .. 11
Trouble- Causes and Remedies ...................... 13
Disassembling and Rea ss embling .. ................ .. 14
Storage of Engine for Winter ...... .... .................... 24
Parts List ........ .. ...................... .. .. .......... .... ........ .. 26
Service Station Di rect ory, See bock of Manual
Carburetor Repair- See Manufacturers Bulle tin
in back of Manual.
Magneto Repa i r- See Manufacturers Bulletin
in bock of Manual.
- - - - *
Air Cleaner
7
Backfire s Through Carburetor. ........................... 14
Battery Igni tion Timer ...................................... .. 11
Ca mshaft and Valv e Tappets .. .... ........ .............. 21
Carburetor ......................................................... ..
8
Clutc h Tok e-Off .... .. .... .. .... .... .... .... ...... .. .............. 23
Clutch Adjustment .............. .. .......... .. .... .............. 24
Clutch Reduction Gears ...... .. .............................. 24
Compression ........................................................ 13
Compression - Rest oring .............. ...... ...... .. .... .. 11
Choke .................................................................... 8
Cooling .... .... .. .............. .. ................ ................ .. .... ..
6
Ml-207 2
PAGE
Crankshaft ( End Ploy).......................................... 20
Electric Starter and Generator .. .. .... .... .. .. ............ 11
Engine Speed ....... :-.. ............ .. .................. .. .............. 22
Fuel ............................ .. .. .... .. .... .. ............................ 8
Fuel Pump .. .......... .. ................................................ 9
Fuel Strainer .... .. .............. .. .................. .................. 8
Governor - Adjustment .. ........ .. ...................... .. .... 22
Ignition Switch .. .................................................... 9
Ignition Troubles .................................................. 14
Knocks - Engine .. .... ...................................... ...... 14
Lubrication .. .... .. .. .... .... .. .... .... .. .. .. .. .. .. .... .. .. .. .... .. .. .. 7
Magneto .................................................................. 9
Magneto -lgn
it ion Spark .......................... .. .......... 9
Magneto- Timing .................................................. 10
Magneto - Drive Shaft and Gear.............. .. .......... 19
Oi I - Grode of ...................................................... .. 7
Oil Pump ................................................ A.............. 21
Over speeding .......................................................... 8
Overheats.. ................................................ .. ............ 14
Piston and Connecting Rod.......... .. ...................... 16
Reduction Gears .. .............. .... .. .... .. .... .... ................ 24
Spark Plug ...... ............................................ .. .......... 10
Starting - Cronk and Rope Starter .......... .. .......... 11
Starting Difficulties .. .. .... .... .. .. .... .... .. .................... 13
Stop Engine .. .. .... .. .. .. .. .. .... .. .. .. .... .. .. .... .. .. .. .. .... ........ 11
Surging or Galloping.... .......................................... 14
Valves ........................ .. .... .... ................................ .. 18
Valve Tappet Adjustment .... .. .............................. 19

MODELS AD H, AE , AEH AND AEHS ENGINES
/ AIR VENT HOLE
Fig. 1
STOP SWITCH
OIL DRAIN PLUG
3
CARBURETO R
THROTILE
LEVER
FUEL liNE
CARBURETOR
NEEDLE VALVE
91661C
GOVERNOR
CONTROL ROD
Fig. 2
GOVERNOR
LEVER
GOVERNOR
SPRING
ROPE STARTER SHEAVE
..
91666C
Ml-208

fLYWHEEL
OIL DRA IN PLUG
Ml-209
MODELS AFH, AG H AND AHH ENGINES
Fig. 3
OIL BATH
AIR CLEANER
MUFFL ER
CARBURETOR
CHOKE LEVER
OP EN
STOP
SWITCH
4
ST OP
SCREW
FUEL
LINE
71675C
Fig. 4 80199C

'
U'l
!
"'
0
Cl'
m
n
::!
i
>
r-
~
m
:E
Cl'
0
"TT
m
%
£!
%
m
Cl'
~
0
m
r- -n
Cl' ~
>
(11
0
~
>
~ m
>
m
::c
>
m
::z:
~ CI'
>
"TT
~
>
(;')
~::z:
>
%
::z:
GOVERNOR SPRING
G<J.IERNOR LEVER
AJR SHROUD
FAN -FLYWHEEL ~t ~
...
CARBURETOR
CHOKE LEVER
NEEDLE VALVE
MECHANICAL GOVERNOR
FUEL TANK
MAGNETO SWITCH
FUEL SHUT·OFF VALVE
OIL TROUGH
\
OIL DRAIN
CRANKSHAFT
' 1-:- · --====F----- AI R
~ CLEANER
'-- \1A1 .VE TAPPER
OIL STRAINER
OIL PUMP
u.s. t8 · 41
•

GENERAL INFORMATION
Wis co ns m heavy duty ai r- coole d engines are of the
most
appro v ed des ign and are bu ilt in a modern fac -
tory, equipped with the latest machi ne ry available.
Only the best materials, most suitable for the partic -
ular pa rt, are used. During production every part is
subjected to the most ri gid inspection, as are also
the completely assembled engines . After assembly
every engine is ope rate d on its ow n power, for sev -
eral hour s, on a dynamometer. All adjustme nts a re
carefully made so that each engine will be in perfect
ope r at ing co ndition when it leaves the factory.
Back
of the Wisconsin Motor Corporation is forty
yea rs of engi neering experience in the design of gaso-
line engines for every conceivable type of service.
The performance of these engines is proof of the long
satisfactory se r vice you too can expect from your
engine.
Like all fine machinery the engine must be given
regular
ca re and be ope rat ed in accordance with the
instructions.
Keep this book handy at all times . Familiarize your-
self w1 th the operating instructions .
GENERAL DESIGN
Wisconsin engines are of the four cycle type , in which
each of the four ope rati ons of s uction, compression,
expansion and exhaust r equires a complete stroke.
This gives o ne power st r oke for each two revolutions
of the crankshaft.
COOLING
Cooling is accomplished by a flow of air, circ ul ated
over the cylinder and head of the engine, by a combi-
nation fan-flywheel encased in a sheet metal shroud.
The ai r JS divided and directed by ducts and baffle
plates to insure uniform cooling of all parts.
Ne ve r operate on engin e with any port of the
sh rouding removecl, because this will re1orcl the
air cooling.
CARBURETOR
The proper combustible mixtu re of gasoline and air
is furnished by a balanced ca rbureto r, giving co rrect
fuel to air ratios for all speeds and l oads.
IGNITION
The spa rk for ignition of the fuel mixture is fu r nished
by a high tension magneto, driven off thetiming gears
at c rankshaft speed . The magneto is fitted with an
1mpulse coupling, which makes possible a powerful
spark for easy starting . A1so, the impulse coupling
automa
ti cally re tard s the t1ming of the spark for
starting , thus eliminating danger of klckback.
OILING SYSTEM
Lubricalion is of the constant level splash type. A
plunger pump maintains
the proper o il level in a
trough under
the connecting rod. See Fig. 6.
Ml·211 6
F ig . 6
723 99C
GOVERNOR
A governor of the ce ntrifugal flyball type contr ols
the engine speed by va r ying the thr ottle opening to
su it the load imposed upon the engine.
When the engine is at rest, the gove rn or will hold
the throttle valve wide open, but as soon as the en-
gi ne is s tarted, the governor will r egulate the speed,
at the predetermined re vol utions per minute. In order
to give close regulation, the govern or spring mu st be
suited to the speed required.
ROTAT IO N
The r otation of the cr anks haft is cl ockwise when
viewing from the flywheel or starti ng end of the en -
gine. This gives counte r-cloc kwise rotation when
viewing the power take-off end of the cranksh aft.
HORSE POWER
The MQC!el AEHS engine has a higher compression
than the Model AE H, and is intended for higher speed
installations. In other details the engine is simil ar
to Model AEH. Due to the higher compr ession this
engine cannot be ope r ated below 2000 R.P. M., other-
wise detonation will res ult, with its evil effects .
R.P.M. AOH
AE AEH AEHS
AFH AGH AHH
1400 2.7 3.25 3.3 -- 5.3 6.4 6.8
1600 3.2 3.75 3.9
--
6.0 7.2 7.7
1800 3.6 4.15 4.4
--
6.6 7.8 8.5
2000 4.1 4.5 4.9 5.2 7.0 8.2 9.0
2200 4.5 4.8 5.4
5.9 7.2 8.4 9.2
2400 4.8 5.0 5.7 6.5 --
-- --
2600 5. 1
5.1 6.1 6.9
--
--
--
2800
-- -- -- 7.2
-- --
--
3000 -- -- -- 7.4 -- --
--
3200
--
-- -- 7.4
--
--
--
The horse power given in the above chart is for an
atmospheric tempe r ature of 60° Fahrenheit at sea
level, or at a Barometric p res sure of 29 .92 inches of
me rcury.
For each inch lowe r Bar ometric p re ss ure, the re will

be a 3~% loss in ha:se power,
For each 10° temperature rise the re will be a reduc-
tion in horse power of 1%. For each 1000 ft. altitude
above sea level there will be a redu ction in horse
power of 3% .
The friction in new engines can not be r educed to the
ultimate minimum during the r eg ul ar block test, but
engines are guaranteed to develop at least 85 per
cent of maximum power when shipped fr om the fac-
tory. The power will inc r ease, as friction is reduced,
dur ing a few days of ope r ation .
INSTR U CTIONS FO R ST A RTING
AND OPER AT IN G
LU BR ICATI ON
Before starting t he engine , fill the base with good
gas engine oil through the fill er f>l ug op eni ng. See
Fig's . I and 3. The oil shoul d be filled to the level
of the filler plug hole, Be su re the o il is clean, and
also the funnels or measu r es u sed in filling .
Too much emphasis cannot be given to the matter of
oil s el eetion. ll tgh ~adc oil of the body sui ted to
the requirements of your engi ne is the most important
single item in the economical oper ation of the unit,
yet it is the cheapest item of operating cost. Select
your oil solely on quaLity and suitability-never on
price-for no one thing is so sure to bnng about un-
satisfac tory performance and unnecessary expense
as incorr ect lub r ication.
High-grade, highly refined oils co rr esponding in body
to the S. A. E. (Society of Automot iv e Eng in eers)
Viscosity Numbers listed below will prove econom-
ical and assure long engine I if e.
IM P OR TANT: S. A. E. Viscosity numbers classify
oils in terms of body only without consideration of
qua
li ty or character, therefo re we list certain gr ades
of Mobil oil as typical examples of lubricants possess-
ing the qualities we believe desirable in o il s for
Wisconsin engines. We plainly state that these grades
of M obiloils are listed because of their recognized
quality and world-wide dist ribution. There ore other
high qua lit y oils on the mar ket that are equally sat-
isfactory for Wisconsin engines.
GRADE OF OIL
SEASON OR
GR ADE
E XA MPLE
TEMPERATURE OF OIL
Spring, Summer.
or Autumn
SAE 30
Mobi.Loil A
+ 120~ to +40°F
Winter
SAE 20-20W Mobiloll Arctic
+40~ to +5°F
'
Winter
SAE lOW Mobiloll lOW
+ S~ to -20~
Crankc ase Capacit y_
ADH, AE, AEH, AEHS 2Y, Pta.
AF II AGH AHH
2V.. Qta.
7
Follow summer r ecommendations in winter if engine
is housed in warm building.
Check oi I level every 8 hours. The ol e/ oi I3houlcl
be c/ r ai necl eve ry 50 hours of ope r ation.
To d rain oil base , remove oil drain plug. See Fig's .
I and 3. Oil sho uld be dr ained while engine is hot,
as it will then flow mo re freely.
A IR C LE ANER
The ai r cle aner is an essential accessory, filtering
the a ir ente rin g the ca r bureta:, and thereby prolong-
ing the life of the engine, To se rvic e, unsc r ew wing
nut , remove cpve r and filtering element. See Fig. 7.
Fill bowl to oil level line with the same kind of oil
as u se d in the cr ankcase. This requires app r oximate -
ly ~ pint. The filtering element should be washed in
solve nt if it shows sig ns of collected dust. Detailed
instructio ns are printed on the air cleaner.
AIR CLEA N ER
BOW L
Fig. 7 83461C
The ai r cl eaners must be se rv iced frequently, depend-
ing on the dust conditions where the engines are
ope r ated . Whe n the oil in the bowl becomes dirty, it
sho uld be replaced with new oil. This servicing will
vary from a few days of operation in comparatively
clean condi ti ons to twice a day in dusty conditions .
Operating the engine uncler c/us ty cone/it ions
without oil in the air cleaner, or with c/irty oil,
may wear out cylinders, pistons, rin gs one/ bear-
·
ings in a lew clays ti r~te, one/ result in costly
repa irs.
Dail y attention to the ai r cleaner is one of the most
impor
tant co n side r ations in prolonging engine life .
Ml-212
•
4

FUEL
The fuel tank should be filled with a goocl quality
gasoline free from dirt and water . Some of the poorer
gr
ades of gasoline contain gum which will deposit on
valve stems, piston ri ngs, and in the various small
passages in the carburetor, causing serious trouble
in operating, and in fact might prev ent the engine
from ope.:ating at all.
Use only reputable, well known brands o( Regular
gasoline. Fuels with the lowest possible lead con-
tent, but not below octane rating 74 (Research Meth-
od), are
best. Fuel with a lower octane rating will
cause detonation, and if operation is continued under
this condition , severe damage will result: cylinders
and pistons will be scored, head gaskets blown out,
bearings will be damaged, etc.
Be su re to open the gasoline shut -off valve below
the fuel
tank. See Fig's . 1 and 3. Also be sure air
vent hole in fuel tank cap is clear, otherwise gas
cannot flow to carburetor.
FUEL STRAINER
Fig. 8 71679C
the fuel strainer on the bottom of the fuel tank is
very necessary to prevent sediment, dirt, and water
from entering the carburet or and causing trouble, or
even complete stoppage of the engine. The gl ass
strainer bowl should be inspected frequently and
cl ea ned if dirt or water is present. To remove bo wl,
first shut off fuel valve, then loosen the knurled nut
below the bo wl and swing the wire bail to one side.
After cleaning the bowl and screen , replace the parts,
being sure that the gasket is in good condition; if
not, use a new gasket. See Fig. 8.
CHOKE
Before starting a cold engine, close the choke on
the
carburetor air inlet horn by pushing the choke
lever down. See Fig. 2. The choke will remain closed
until the engine starts, at which time .i.t will open
automatically, If the choke should accidentally snap
open before the engine starts, close it again. Less
choking is necessary in warm weather or when the
engine is warm than when it is cold .
n
If after several unsuccessful attempts to stait the
engine , gasoline begins to drip from carburetor, the
choke should be opened, by pushing choke lever up-
ward, o t h e r w i s e the fuel mixture may become too
rich to burn. The regular sta r ting procedure should
then continue as in the paragraph on Starting, Pag e
ll, but with the choke open.
CARBU RETOR
These e ngine s are eq,uipped with either a Zenith or
Stromberg carbur etor .
The high speed needle valve on the carburetor should
be opened app r ox im ately~ to liA turns . See Fig's. 1
and 4.
After the engine is started and warmedup for several
minutes, and runnjng at normal operaUng speed, this
needle valve shou!d be readjusted for best operation.
This adjustment need only be made the first time the
engine is started.
After that the needle should be left in that position.
In cold weather, starting may be facilitated by open-
ing the needle valve slightly more, then readjusting
to normal running position after engine is started.
The idle needle should be ad j us ted for best low
speed operation, while carburetor throttle is closed
by hand.
For further information on the carbu r etor, see Manu-
facturer's Instruction Bulletin in back of this manual.
OVERSP EEDING
When starting a gasoline engine for its days work,
the engine should be allowed to wann up to operating
temperature, befo re the load is applied. This requires
only a few minutes of running of the engine at mod-
erate speed.
Racing an engine or gunning it, to hurry the warm-up
period,
is very destructive to the polished wearing
surfaces on pistons, rings, cylinders, bearings, etc.,
as the proper oil film on these various surfaces can-
not be established until the oil has warmed up and
become sufficiently fluid. This is especially impor-
tant on new engines and in cool weather.
Racing an engine by disconnecting the governor, or
by doing anything to interfere with the governor con-
trol of the speed of the engine, is extremely danger-
ous . Quite naturally the ope r ator of the engine
desires to get all possible power out of an engine,
and the engine manufacturer does his best to supply
this want, but if all of this power is used merely to
speed up the engine, without any load being imposed
upon
it, dange r ously high speeds will result.
The governor is provided as a means for controlling
the engine speed to suit the load applied, and also
as a safety measu re to guard against excessive
speeds, which not only overstrain all working parts,
but which might cause wrecking of the engine, and
possible injury to bystanders.

All parts of the engine are designed to safely with-
stand any speeds which might normally be required,
but
it must be remembered that the stresses set up
in rotating parts, increase with the square of the
speed. That means that if the speed is doubled the
stresses will be quadrupled, and if the speeds are
trebled the stresses wi 11 be nine times as great.
Therefore
strict adherence to the above instructions
cannot be too strongly urged, and greatly increased
engine life will result as a reward for these easily
applied recommendations.
FUEL PUMP
Fuel pump is an optional accessory. Due to special
machining of crankcase, fuel pump can be furn ished
only upon request , when engine is purchased from
factory.
The fuel pump is a product of AC Company,
Flint, Michigan, and it is recommended that all re-
pairs and parts be purchased through their Service
Stations.
IGNITION SWI TC H
The magneto ignition is standard on these engines.
A grounding switch, located •" on the side of the mag-
neto, is al~ays in the ON or running position, except
when depressed by hand for stopping. See Fig's. 2
OTid 4.
MAGNET O
Magnetos are properly adjusted and timed before leav-
ing the factory. The breaker points on the Foirbonlcs-
Mor se magneto and on the Wic o magneto should be
.015" at full separation. If the spark becomes weak
after continued operation, it may be necessary to
readjust these points.
Fig. 9 TI599C
To do this, first remove the end cover on the mag-
neto . See Fig. 9, which shows the end cover removed
and the breaker points of the Foirbonlcs-Morse mag-
neto exposed. The following inst ru ctions are for the
Foirbonlcs-Morse magneto, but can be applied to other
9
magnetos used on this model of engine. For further
information, see service instructi ons for th e Fair-
bonlcs-Morse one/ Wico magnetos in the bode of this
manual. The crankshaft should be rotated by turning
the engine over by hand, (this also rotates the mag-
neto), until the breaker points are wide open. The
opening or gap should then be meas ur ed with a feeler
ga u ge and if necessary re set as shown in Fig . 10.
COIL
CONDENSER
MEASURE BREAKER
POINT GAP WHEN
OPEN. ADJUST TO
.015 INCH
BREAKER ARM
CONTACT SUPPORT
LOCKING SCREWS
ADJUSTING SLOT
1____:: ~-II!!!:: :.:::::::::J. _ TERM IN AL SCREW
END VIEW OF FA IRBAN KS - MORSE MAGNETO
Fig . 10
. .
To r eadjust points, loosen the contact support lock -
ing screws, then move the contact support until the
proper breaker point clearance is obtained. This is
accomplis hed by means of a screw driver inserted in
the horizontal slot at the bottom of the contact sup-
port and pivoted between the two small bosses on
the bearing support. Lock the assembly in place by
tightening the locking screws and make a final meas-
urement of the breaker point gap after the locking
screws are tightened .
If it is found that the breaker points have become
rough,
they should be resurfaced with a breaker point
file before the above ad justment s are made. Then re-
place magneto end cover carefully so that it will
se al prope rl y. Do not force cover screws too tightly
on the magneto as the cover may cr ack.
MAGNETO IGNITION SPAR K
If difficulty is expe rienced in starting the engine or
if engine misses firing, the strength of the ignition
spa rk shou ld be tested . Remove the ignition cable
from the spa rk plug and hold the ignition cable ter -
minal about 1/8 inch from any metal part of the en-
gine . Keep hand on ins ula ted part of cable to avoid
a
shock and turn motor with starting crank or sheave
as shown in Fig . 11.
When the impulse coupling on the magneto snaps
there should be a good spark at the ignition cable
terminal. If the re is a weak spark, or none at all,
first check break er point opening as mentioned on
preceding paragraph under Magneto. If this does not
remedy the trouble, it may be necessary to install a
new
condenser. See Fairbanks-Morse or Wico main-
tenance manual at the back of this book.
Ml-214
..

Fig. 11
MAGNETO TIMING
When timing or mounting the magneto, the piston must
be on top dead center, which is accomplished when
U1e marked air vane on the flywheel registers with
the mark on the vertical centerline of the flywheel
air shroud. This mark is visible when the flywheel
air screen is removed. See Fig. 15.
Place coupling drive disc on the lugs of the magneto
drive
shaft of the engine. The drive lugs on the mag-
neto should then be turned counter-clockwise until
they
engage the impulse, In turning the drive lugs
coun ter-clockwise, it will be found that a point of
conside rable resistance is met. This is the point at
which the impulse is contacted and it wi 11 be found
that
the lugs on the magneto will n ow line up with
slots in the coupling disc. The magneto should then
be secu red to the pad with the two capscrews and
lockwashers provided and these should be drawn
down
loosely. Before tightening the screws, the mag·
neto must be lined up as nearly as possible on the
same
center line as the rna gneto drive shaft.
The purpose of the coupling disc is to take care of
slight misalignment which may exist, but it is very
important
that this misalignment be kept at a min·
imum. If it is not, wear on the coupling will be quite
rapid. The d i stance across the coupling slots is
slightly more than the distance across the lugs on
the drive shaft by 1/8". When th1s clearance is equal-
ly divided, there will be about 1/16• clearance on
each side of the disc. Sec Fig. 12. An alignment
M l- 215
MAGNETO
DRIVE lUG
1 16"
Fig. 12
COUPliNG DISC
INSER T HOOK END
OF OAUGE HERE
78864C
10
Fi g. 13 77519C
gauge may be made out of a piece of 1/16" thick
metal. To get the exact alignment insert the hook end
of the gauge into the side clearance slot . Then swing
the magneto in the direction which will tend to pinch
the gauge in this slot and tighten the mo u nt i n g
screws. See Fig. 13. In order to recheck the timing,
the crankshaft should be turned over in a clockwise
direction when facing flywheel end and it will be
noted that the impulse coupling in the magneto will
snap when the 'D.C.' marked vane on the flywheel,
registers with the mark on the vertical centerline of
the flywheel ai r shroud. If the impulse coupling
snaps before or after the marked vane reaches the
top, the magneto drive shaft cover should be removed
and
the gears should be checked to see if the Timing
mark
on the magn~to gear lines up with the mark on
the camshaft gear. See Fig. 34. A spo rlc o c/ vonce o f
25° is use e/ .
SPAR K PLUG
The spark plug gap should be maintained at .030•.
Approximately every 100 hours of operation, the plug
should be removed and inspected . The spark plug
points should be
scraped clean and the plug thorough-
ly washed in alcohol. To set the points, a spark plug
wrench or any
similar tool should be used. See Fig.
14.
If the por celain insulator is cracked , replace with a
new plug
of co r rect heat range, like Champion ID-16,
Fig. 14

AC No. C86 Commercial, or equal. The spa rk plug
thread is 18 millimeter. Be sure to use a good gasket
under the spark plug. Tighten spark plugs, 25 to 30
foot pounds torque.
IGNITION CABLE
When inspection of the spark plug is made, the igni-
tion cable should also be inspected. If the cable
shows signs of cracking insulation, it should be re-
placed.
BATTERY IGNITION TIMER
When battery ignition is u sed on these models of en-
gines, a timer is mounted in place of the magneto. A
gear on the timer
shaft engages the camshaft gear
and drives the timer
at engine speed in a clockwise
direction, when viewed from the break er . point end.
When timing or mounting the ignition timer, the pis-
ton must be on top dead center , which is accomplish-
ed when the
ma rk ed air vane on the flywheel registers
with the mark on the vertical centerline of the fly-
wheel air sh roud. This mark is visible when the fly-
wheel air screen is removed. See Fig. 15.
The distri but ex body is kept from rotating, and it is
held in proper position by a clamp lever, by means of
which the timing adjustment is also made.
Remove timer cover
to facilitate correct mounting.
Refer
to Fig. 16 . Set timer in place, with round head
screw on body touching magneto mounting bracket,
and cam in position with breaker
points begirming to
open. Pin gear to timer shaft in relation to timing
marks stamped on timer gear
and camshaft gear. See
Gear Train, Fig. 16.
The· proper ignition advance is 25° of crankshaft or
timer rotation. The timer has an automatic advance
of 15°, thus requiring an initial advance setting of
the timer of 10 °. To get the initial 10° advance , the
timer body should
be rotated in a counter-clockwise
direction, through
an angle of 10°, which is equal to
7/32 inch on the outside circumference of the timer
body.
It is necessary to loosen the clamp lever to
make the above adjustment, but this lever shou ld then
be firmly clamped again.
If a Neon timing lamp is available, the timin.g may
be
checked as follows: F ir st whiten the end of the
marked vane on the flywheel with chalk. Connect the
Neon lamp in series with the spark plug. Run the en-
gine at 1800 R.P.M. or over, and with the flash from
the lamp illuminating the white vane, its leading
edge should register with the advance mark on the
flywheel shroud.
Breaker point full opening should
be .020 inch.
START ING-CRANK AND ROPE STARTER
These engines can be furnished with either starting
cr
anks or rope starters.
Rope starters are preferable for the smaller engines,
Models
ADH, AEH and AEHS. The larger engines,
11
Models AFH , AGH and AHH, require a little harder
pull for starting and for that reason a starting crank
is preferable.
The starting crank should be engaged at the flywheel
end,
in such a position that it can be pulled up for
sta rting, instead of pushing down on crank. In the
latter case the ope t a to r might be injured, if there
should be a
back fire. If the engine does not start on
the first pull of the crank, it should be engaged again
and the operation repeated.
On engines equipped with rope s t a rt e r s, the rope
should be wound on
the starting sheave in a clock-
wise direction after the knot in the end of the rope
bas been inserted in the notch in the sheeve. Pull
gently on the rope until increased resistance is felt.
The piston is then starting on the compression
stroke . Now rew ind the rope fully on the sheave and
pull briskly so as to turn the crankshaft over rapidly.
If all conditions are right, engine will start promptly,
after one or two applications of the rope. Aft er the
engine
starts, allow it to wann up a few minutes, be-
fore applying load. ..
ELECTRIC STARTER AND GENERATOR
The electric starter is an optional accessory. Due to
special machining, can only be furnished wh en en-
gine
is ordered from factory. The starter and gen-
erator are products of Electric Auto-Lite Company,
Toledo, Ohio, and
it is recommended that all repairs
for
their accessories be done through their authorized
se rvice stations. Battery is not furnished by engine
manufacturer.
RESTORING COMPRESSION
On a new engine or one which has been out of opera-
tion for some time the oil may have drained off the
cylinder
so that compression will be weak. This may
cause difficulty in starting. To remedy this condition,
remove the spark plug and pour
about a fluid ounce
of crankcase oil through the spark plug hole. Turn
the engine over several times with the rope starter
to distribute the oil over the cylinder waH. Then re-
place the spark plug and compression should be sat-
isfactory. When comp ressi on is proper, considerably
more resistance will be felt in cranking on one stroke
of the piston, the compression st roke, than on the
othe r th r ee strokes.
TO STOP ENGINE
To stop engine, depress ground switch on magneto
with thumb, and hold down until
engine stops. See
Fig's. 2 and 4.
SAFETY PRECAUTIONS
Never fill fuel tank while the engine is in operation.
Gasoline spilled on a hot engine may explode.
Never ope
rat e engine in a closed building unless the
exhaust is piped outside . Exhaust from an engine
contains carbon monoxide, a poisonous, odorless and
Mt-216-2
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SPARK PLUG
COIL
CRANKSHAFT GEAR
LINE UP TIMING MARKS AND PIN
TIMER DRIV£ GEAR AF"TER SETTING
IGNITION TIMER AND BREAKER CAM
IN POSITION AS SHOV;N IN R.H. VIEW
+
CLAMP
MARK ON VERTICAL
CENTERLINE
MARKED AiR VANE
ON l"LYWHEEL------t
..
- ----
ENGINE ROTATION \ I I ~ I
(CLOCKWISE) i • 1
~MER
WHEN ENGINE IS SET TO RUN. ADVANCE
TIM€R BOOY IN COUNTER-CLOCKWISE
ROTATION APPROXIMATELY 10°
TIMER SHAFT ROTATION
(CLOCKWISE)
COVER
,--~-~
·~ rp,~~ P04NTS JUST
BEGINNING TO OPEN/
' (SET BREAKER GAP .0 20")
SET TIMER IN PLACE WITH HEAD Of' ScREW
TOUCHING MAGNETO MOUNTING BRACKET

invisible gas, which if br eath ed into the lungs would
ca u se serious illness and possible death.
Never make a djus tments on any kind of machinery
while
it is connected to the engine without first re-
moving the ignition cable from the spark plug. Turn-
ing over the machinery by hand during adjusting or
cleaning might sta rt the eng ine and the machinery
with it, causing serio us injury to the operator.
Always keep all ports of the engine clean. Th is
wi II prolong engine Iife, one/ give more sati s-
Factory operation,
Every 4 to 8 hour s, depending on dust co nditions,
check air cleaner and change oil if dirty. See Page 7.
Every 8 hours check crankcase oil level . Keep filled
to level of oil filler h ole . See Page 7.
fv ,ery SO hours drain cra nk case and refill with fresh
oil. See Page 7.
TR OUBLE
CAUSES AND REMEDIES
Three prime requisite s are essential to starting and
maintaining
sa tisfactory ope rati on of gasoline en-
gines. They are:
1. A proper Fuel mixture in the cyUnder.
2. Gooc/ compression in the cylinder .
3.
Gooc/ spark, properly timed, to ignite the
mixture.
If all three of these conditions do not exist the en-
gine cannot be sta rted. There are other factors which
will contribute
to hard sta rting; such as, too hea vy a
load
for the engine to turn over at a low starting
sp eed, a long exhaust pipe with high back pressure,
etc. These conditions may affect the starting , but do
not
necessarily mean that the engine is improperly
adjusted.
As a guide to locating any difficulties which might
ari
se , the following causes ~1re listed under three
headings: Fuel Mixture, Comp re ssion, on e/ Ign ition.
In each case the causes of trouble are given in the
order in which they
are most apt to occur. In many
cases the remedy is apparent, and in such cases no
further remedies
are suggeste d.
ST ART ING DIF FICUL TIES
FUEL MIXTU RE
No fuel in tank or fuel shut -off valve closed .
Carburetor not choked sufficiently,
especially if en-
g ine is cold. See 'Choke', Page 8.
Water, dirt, or gum in gasoline interfering with free
flow of fuel
to ca rbur etor .
Poor grade or stale gasoline that will not vapo riz e
sufficiently,
to form the proper fu el mixture.
Needle
valve on carburetor ins uff ic ie ntly open ed .
Carburetor flooded,
ca u sed by too much choking es-
13
pecia lly if engine is hot. See 'Choke', Page 8.
Dirt or gum w ill hold float n eedle valve in carburetor
open.
This co ndition would be indicated if fuel con-
tinues to drip from carb uretor while engine is idle .
Often tapping. the
fleet chambe r of the carburetor
lightly with the wood handle of a
screw driver or sim-
ila r instrument will remedy this trouble. Do not strike
with any me tal tools , it ma y cause damage. Also if
the mixture in the cyl inder, due to flooding, is not
too r
ich, starting may be accomplished by continued
cranking with the carbu re tor choke open.
If due to flooding, too much fuel should have entered
the cylinde r in attempting to start the engine, the
mix
ture will most likely be too rich to burn. In that
case the spa rk plug should be removed from the cyl-
inder and the engine then turned over several times
with the starting rope, so the rich mixture wi 11 be
blown out
thr ough the spark plug hole. The choke on
the
carbureto r should of course be left open during
this procedure. The plug should then be repla ced and
sta r ting tried again.
To test for clogged fu el line, loosen fuel hne nut at
carburetor slightly. If line is open, fuel should drip
out at loosened nut.
COMPRESS I ON
If the engine has proper compression, cons iderably
more
resistance will be encountered in the pull on
the s
tarting rope, on one st roke of the piston as com-
pared
wiU1 the other three strokes. If this resistance
is not encountered, compr ession is faulty. Following
are some reas ons for poor compr ess i on:-
Cy linder dry due to engi ne having been out of use for
some
~me . See 'Restoring Compression', Page 11.
Loose spa rk plug or broken spa rk plug. In this case
a hissing noise will be heard in cranking engine, due
to escaping gas mixture on comp res sion st roke.
Damaged
cylinder head gasket or loose cylinder head.
This w ill lik ewise cause hissing noise on compress-
ion stroke .
Valve
stuck open due to carbon or gum on valve stem .
Remove
tapper inspecti on plate and note if valves
are moving up and down as engine is turned over by
hand. A st u ck valve will n ot follow down. To clean
valve stems, see 'Valves', Page 18 .
Va lve tappets adjusted with insufficient clearance
under val ve stems . See 'Valve Tappet Adjustmer~t',
Page 19.
Pistons rin gs stuck in piston due to carbon accumu-
lation.
If rings are stuck very tight, this will neces-
si tat e removing piston and connec ting rod assembly
and clean in g parts . See 'Piston and Connecting Rod'
Page 16.
Scored cylinder . This will require reboring of tht:
cyli nder and fitting with new piston and rings. If
scor ed too severely, an entire new cylinder and crank
case may be necessary.
Ml·218
..
4

I GNITION
No spark may also be attributed to the following:-
Ignition cable disconnected.
Broken ignition cable, causing sho rt ci r cuits.
Ignition cable wet or oil soaked.
Spark
plug insulator broken.
Spark plug
wet or dirty.
Spark plug point gap wrong. See Page 10.
Condensation on spark plug electrodes .
Breaker point pitted or burned.
Breaker arm sticking .
Condenser leaking or grounded.
Spark timing wrong.
See 'Magneto Timing', Page 10.
or 'Battery Ignition Timing'.
ENGINE MISSES
Spark plug gap incorrect. See Page 10.
Worn and leaking ignition cable.
Weak spark . See 'Magneto Ignition Spark', Page 9.
or 'Battery Ig11ition Timir1g'.
Loose connections at ignition cable.
Breaker points pitted or worn.
Water
in gasoline.
Poor compression. See 'Compression', Page 13.
Carburetor incorrectly adjusted.
ENGINE SURGES OR GALLOPS
Carburetor adjustment too rich.
Carburetor flooding.
Governor spring hooked into wrong
hole in lever. See
'Governor', Page 6.
• Governor rod incorrectly adjusted, See 'Governor',
Page 6.
ENGINE S TOP S
Fuel tank empty.
Water, dirt or gum in gasoline.
Gasolint- vaporized in fuel lines due to excessive
heat around engine. (Vapor Lock). Vapor iock in fuel
line
or carburetor due to using winter gas (too vol-
atile) in hot weather.
Air
vent hole in fuel tank cap plugged.
Engine,
scored or stuck, due to lack of oil .
Ignition
troubles. See 'lf{nition' on this page.
E NGINE OVERHEATS
Restricted cooling air ci r culation .
Part o( air shroud removed from engine .
Ml·219 14
Dirt between cooling fi ns on cylinder or head•
.
Engine operated in co nfined space, where coo l ing
air is cont in ua lly recir culated , conseq ue ntly becom-
ing too hot .
Crankcase oil supp ly lo w. Replenish immediately.
Carbur
eto r i ncorrectly adjusted .
Ignition
spark timed wrong. See 'Magneto Timing'
Page 10.
Low grade of gasoline.
Engine overl oaded.
Carbon in engine .
Dirty or
inco rr ect grade of cr ankcase oil.
Restricte d exha u st .
Engine
ope r ated wh il e detonating due to low octane
gasoline or heavy load at low speed.
ENGINE KNOCKS
Poo r gr ade of gasoline or of low octane rating . See
'Fuel', Page 8.
Engine operating under heavy load at low speed .
Carbon or
lead deposits in cylinder head.
Spark
advanced too far. See 'Magneto Timing', Page
10 or 'Battery Ignition Timing', Page ll.
Loose or burnt out connecting rod bearing.
Engine
overheated due to ca u ses under previous
heading.
Worn or l oose piston pin.
ENGINE BACKFIRES THROUGH CAR B URETOR
Water or dirt in gasoline.
Engine cold.
Poor grade of gasoline.
Sticky inlet valve. See 'Valves', Page 18.
Overheated valve .
Lean mixtur e.
Spark plug too ho t. See 'Spark Plug', Page 10.
Hot carbon parti cles in engine .
DISASSEMBLING AND
RE ASSEMBLING EN GINE
Engine repairs should be made only by a mechanic
who has had experience in such work. When disas-
sembling the engine, it is advisable to have several
boxes availab le so that parts belonging to ce r tain
groups can be kept together, such as, the cylinder
head sc r ews, etc . Capscrews d various lengths are
used in the engine, therefoce, great care must be ex -
er
cised in reassembly so that right screws will be

MOUNTING SCREWS
1\
4 .. &
Fig. 17
80200C
used in the various places, otherwise damage may
result.
Tighten the capscrews and nuts of the cylinder heacl,
cylinder block, manifold, connecting rod, main bear-
ing plate, engine base and spa rk plug, to the spec-
ified torque readings indicated in the following para-
graphs of reassembly.
With the disassembling operations, instructions on
reassembling
are also given, as often it will not be
necessary to disassemble the entire engine. If it is
desired to disassemble the enti re engine, the rea s-
sembly instructions can be looked up later under the
headings of the
various parts.
While the engine
is partly or fully dismantled all of
the parts should be thorougliy cleaned. Remove all
accumulated dirt between the fins on cylinder and
head.
MAG~ETO A~D COUPLI~G DISC
To remove the magneto, remove the 2 capscrews and
lockwashers which
secure the magneto to the pad on
the crankcase. Refer to 'Magneto Timing', Page 10
for reassembly.
CARBURETOR, MANIFOLD A~D AIR CLEA~ER
Loosen the fuel line at the carburetor. Next, loosen
the breather line at the cylinder. Then remove the
cotter pin from the governor control rod and pull the
rod out of the governor control lever . Then loosen
and removethe capscrew and lockwasher which holds
the air cleaner bracket to the engine . Next, loosen
and remove the 2 capscrews and lockwashers which
clamp the manifold
tothe cylinder. The entire assem-
bly of the manifold, carburetor and air cleaner can
then be removed . rn reassembly, tighten manifold
mounting
screws , for Models ADH, AE, AEH, AEHS,
14 to 18 foot pounds torque and for Models AFJI,
AGH, AHH, 25 to 32 foot pounds torque.
15
flYWHEEl SCREEN /
Fig. 18 71677C.
REMOVAL OF FUEL TANK A~D FUEL S TRA INER
The fuel line should be loosened at the strainer and
taken off
the engine. Removethe capscrews a.nd lock-
washers which hold the fuel tank bracket to the
crankcase. The assembly of the fuel tank, fuel strain-
er, and fuel tank straps and bracket can be removed
as an assembly . The fuel strainer is mounted to the
tank with a 1/8•
close nipple and the strainer can be
removed by unthreading
from this nipple. See Fig. 17.
FLYWHEEL
On engines with starter she ave, first remove this
sheave which is threaded on the crankshaft. Then
remove the four round head screws which hold the
flywheel
screen to the shroud. The screen can then
be lifted off the shroud. On engines with starting
crank, remove the starting nut which is threaded on
the
crankshaft . The flywheel fits on a taper on the
crankshaft and is easily removed. It should be grasp-
ed with the left hand and the end of the crankshaft
should be struck several sharp blows with a babbitt
hammer.
(A void damaging thread on end of crankshaft)
The flywheel will then slide off the taper. See Fig.
18. When reassembling flywheel, be sure Woodruff
key
is in posHion in shaft and that keyway in fly-
wheel is lined up accurately with key.
CONNECTING ROD INSPECTION PLATE
This type of engine is fitted with a connecting rod
inspection
plate so that a visual inspection may be
made of the lower
connecting rod bearing, and if nec-
essary, the rod can be adjusted. To remove the plate,
remove the 6 ca pscrews and 1o c k washers which
secu re the plate tothc crankcase . The plate can then
be pulled
off the engine. See Fig. 19.
Ml-220
•
4

t
Fig. 19 71664C
AIR SHROUD AND COVER
Remove the capscrews which hold the shroud support
straps to the engine base. Loosen the governor spring
at the governor lever. Next, loosen and remove the
capscrew which holds the shrc;ud to the cylinder (this
is located above the manifold).
Next, remove
the nuts which hold the air shroud cover
in
place. Then, remove the capscrew and lockwasher
which holds
the rear of the shroud to the cylinder.
The shroud and cover can then be pulled off the en-
gine. Never operate the engine with any part of the
shrouding damaged or removed. See Fig. 20 .
CYLINDER HEAD
The c ylinder head must be removed if it is necessary
to regrind valves or to do work on the piston rings or
co
nnectin g ro d. All of th e cylinder head bolts are
plainly in view and can be easily removed. Bolts of
different lengths are used, but these can be properly
reassembled according to lhe various lengths of cyl-
inder head bosses. Before reassembling the cylinder
head,
all carbon and lead deposits should be remov-
ed. It is recommended that a new cylinder head gas-
ket be used on reassembly as the old gasket will be
compressed and hard, and
it may ·not seal properly.
See Fig. 2 1.
Tighten cy Iinder head screws, to 32 foot pounds
torque.
PISTON AND CONNECTING RO D
The connecting rod and piston assembly can be re-
moved either through the top of the cylinder by means
of
the connecting rod inspection plate opening, or
after
the engine is entirely disassembled, it may be
removed
from the bottom of the crankcase . In most
cases, it should not be necessary to remove the en-
gine base and in the explanation following, we list
Ml·221
16
Fig. 20
71 6 80 C
the procedure for removing the connecting rod and
piston without first removing the engine base: First,
remove the cotter pins which lock the connecting rod
bolt nuts in place . On later engines pal nuts and plain
hexagon nuts replaced the slotted nuts and cotter
pins . Then, using a socket wrench, loosen and re-
move the connecting rod bolt nuts.
It will be noted upon inspection that both the con-
necting rod and the connecting rod cap have an arr ow
or number on one side of the bolt boss. The cap must
be assembled to the rod so that the two marks are on
the same side. See Fig. 22.
After
the two bolts are removed, the cap can also be
removed. Be sure the shims under the cap are kept
in their places. The piston and rod can then be push-
ed out of the top of the cylinder. Se e Fig. 23. Wash
the pa rts thoroughly in Kerosene, after s~raping off
any
ca rb on deposits .
Fig. 21
7751 6C

Fig. 22
71668C
The pistons are tapered, being smaller at the upper
than
at the lower end. The clearance between the
lower end of the piston and the cylinder is as follows
on the various models:
Model ADH -.004 to .0045 inch
Model AE -. 004 to .0045 inch
Model AEH -.004 to .0045 inch
Model AEHS -.0065
to .007 inch
Model AFH -.0045
to .005 inch
Model AGH -.0055 to .006 inch
Model
AHH -.0055 to .006 inch
Piston ring side clearance in grooves is .002 to .003
inch.
Fig. 23
77514C
17
Fig, 24 71 152C
Pisto n ring gap width is .012 to .022 inch.
Piston pin clea r ance in bushing . 0005 to . 001 inch.
Conn
ecting r od to crankpin clearance .0007 to .002
inch.
Connecting rod
side clearance on crankpin . 004 to
.010 inch.
Rings should be reassembled to the piston as shown
in Fig. 24. On Model ADH the piston is fitted with
two
compression and one oil regulating ring . The
AEHS engine has two compression rings in the top
two grooves, one scraper ring in the third groove and
one oil r
egulating ring in the fourth groove. Models
AE, AEH, AFH,
AGH and AHH have three compress -
ions and one oil regulating ring each .
The scraper and oil rings must be assembled to the
piston with the scraper edges down, otherwise oil
pumping will result . See Fig. 25.
UPPER END OF PISTON
.........---- ~ ' ---
Fig. 25 14178SC· 1
Ml·222
..
4

•
•
--- HAMMER HANDlE
Fig. 26
71721C
When reassembling the piston into the cylinQ.er, a ring
compressor should be used to compress the rings so
they will enter the cyUnder . See Fig. 26.
Assemble the piston to the connecUng rod with the
split side of the piston opposite the oil hole in the
connecting rod cap. The connecting rod should be
assembled to the crankshaft so the oil hole in the
cap will be toward the carburetor side of the engine,
otherwise the rod bearing will not be properly lubri-
cated.
Tighten the connecting rod nuts, for the Models ADH,
AE, AEH and AEHS, to 18 foot pounds torque. For
Models AFH, AGH and AHH, tighten to 32 foot pounds
torque.
Install •pal' locknuts and tighten with wrench
Y.. turn beyond 'finger-tight' position.
CYLINDER BLOCK
The 4 capscrews and lockwashers which secure cyl-
inder to the crank case should be removed and the
cyli nder assembly together with the gasket may then
be lifted off the crankcase. See Fig. 27.
If cylinders are worn more than .005 inch over stand-
ard size, they should be reground and fitted with
oversize pistons and rings. This work should be done
at an authorized service station.
In reassembling cylinder block, tighten cylinder
block mounting screws 62 to 78 foot pounds torque.
VALVES
After the cyl inder has been removed from the engine ,
a
standard automotive type valve lifter may be used
and the valve spring compressed. We recommend for
this procedure a No. 358 valve lifter manufactured by
KD Tools of Lancaster, Penn. Wiljh the handle of a
sc r ewdriver or a hanuner, the valve should be tapped
downward and the 2 retainer locks will drop into the
hand. The valves can then be pulled upward, out of
Ml-223
18
Fig. 27 73851C
the guides and the valve spring and seat will fall out
of the cyli n der and can be pulled free. See Fig. 28.
The valves should be cleaned of all carbon and gum
deposits as should also the valve seats, ports and
guides jn the cylinder block.
The valve seats should be reground to a good seat
by sp rea ding a small quantity of fine valve grinding
compound on the valve and then rubbing the valve on
its seat by a back and forth motion with a screw driv-
er or valve grinding tool. See Fig. 29 . Occasionally
rotate valve to another position during the grinding
operation so seat will be ground true. A uniform seat
about 3/32 inch wide should show entirely around the
valves . All grinding compound should be carefully
washed o ff the valves and cyhnder block with gaso-
line or ke r osene .
The valve stems should have a clea rance of .004 inch
in the guides.
RETAINER lOCKS
Fig. 28 71662C