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

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i
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r-
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m
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::z:
~ CI'
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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.