IGNITION SYSTEM
Paragraph
Description 82
Spark plugs 83
Circuit breaker points 84
Condenser 85
Circuit breaker and timer assembly 86
Coil to timer wire 87
Adjust spark control 88
Spark coil 89
82. DESCRIPTION.
=a.= The ignition system differs from that of the conventional
automotive types in that it has no distributor. A circuit breaker alone
is used. Both coil high‐tension winding ends lead directly to both
spark plugs. Thus both plugs spark at the same time, one cylinder being
on compression stroke while the other cylinder is on exhaust stroke.
83. SPARK PLUGS.
=a.= Defective spark plugs are indicated by engine missing,
overheating, knocking excessively, and lacking normal power.
=b. Type.= Spark plugs are medium heat range, manufacturer’s (H-D)
No. 3.
=c. Cleaning.= Do not take plugs apart for cleaning. Use the
sandblast cleaner method.
=d. Point Adjustment.= Bend electrode located in plug base to adjust
point gap 0.025 inch to 0.030 inch.
=e. Replacement.= Use spark plug wrench (41-W-3334) to install plugs,
using new gaskets. Never draw a cool plug up tight in a hot cylinder
head, rather turn down snug and wait l/2 minute until plug base is
warm: then tighten securely. CAUTION: _Take care not to cross‐thread
when installing spark plug._
=84. CIRCUIT BREAKER POINTS= (fig. 49).
=a.= Circuit breaker lever is insulated from ground and connects to
primary wire binding post by means of a “pig‐tail” wire. Stationary
point is grounded to timer base and is movable in order to adjust
circuit breaker points. Circuit breaker points that are burned or
pitted should be renewed or dressed with a clean fine‐cut, contact
point file. The file should not be used on other metals and should
not be allowed to become greasy or dirty. CAUTION: _Never use emery_
_cloth to clean points._ Contact surfaces, after considerable use, may
not appear bright and smooth, but this is not necessarily an indication
that they are not functioning satisfactorily.
=b. Remove Breaker Lever.=
(1) To disconnect condenser terminal, remove nut from end of condenser
and remove gear‐toothed washer, plain washer, and the brass terminal
strip. Do not remove fiber washer and plain washer located back of
brass terminal strip on condenser terminal post.
[Illustration: RA PD 310248
_Figure 49—Circuit Breaker Points Removed_]
(2) Bend brass terminal strip down and remove binding nut which secures
brass terminal strip and breaker lever “pig‐tail” to primary wire
binding post.
(3) Compress breaker lever spring at end of lever, disengaging spring.
CAUTION: _Do not lose spring._ Release and remove lever from insulated
pivot post.
=c. Remove Adjustable Contact Point.=
(1) Remove the two lock screws and washer plate, securing adjustable
contact point assembly to timer base. Point assembly is free to be
lifted off lever pivot stud.
=d. Install Adjustable Contact Point.=
(1) Install contact point assembly, replacing washer plate and the two
lock screws. Do not tighten lock screws until circuit breaker points
are adjusted (step =f= below).
=e. Install Breaker Lever.=
(1) Install brass terminal strip on primary wire binding post.
(2) Connect end of brass terminal strip to condenser terminal post.
Install flat washer, gear‐toothed washer, and nut.
(3) Install breaker lever on pivot post insulated bearing.
(4) Install breaker lever spring. Make sure that ends of spring are
retained correctly.
(5) NOTE: _Keep breaker lever cam very lightly greased._
=f. Adjusting Circuit Breaker Points= (fig. 51).
(1) Correct point gap is 0.022 inch. Circuit breaker point faces must
seat squarely against each other. If bent, square up and aline by
bending contact plate. Turn timer breaker cam until breaker lever fiber
is located on highest point of cam.
(2) With the adjustable point lock screws loose, shift the adjustable
point plate to obtain a 0.022-inch gap between the circuit breaker
points. Measure gap with an accurate thickness gage before retightening
lock screws, and again recheck point gap after tightening the lock
screws. NOTE: _Wrong circuit breaker point gap affects ignition timing._
85. CONDENSER.
=a.= The condenser is connected in parallel with the circuit breaker
points, one of its terminals being grounded (for the adjustable point)
to the timer base by means of the mounting screw, the other terminal
making connection with the circuit breaker lever (for the lever point)
by means of the lever “pig‐tail.”
=b. Remove.=
(1) Unlatch circuit breaker cover retainer and remove cover.
(2) Remove nut from end of condenser and remove gear‐toothed washer,
plain washer, and the brass terminal strip. NOTE: _A small plain washer
and a large fiber washer are located behind brass terminal strip._
(3) Remove screw which secures condenser to timer base. Remove
condenser.
[Illustration: RA PD 310249
_Figure 50—Circuit Breaker (Timer), Disassembled_]
=c. Install.=
(1) Mount condenser on timer housing. Install lock washer and screw.
Make sure small plain washer and large fiber washer are in place on
condenser end terminal screw before connecting the brass terminal strip.
(2) Connect brass terminal strip to condenser. Replace plain washer,
gear‐toothed washer and terminal nut.
(3) Install circuit breaker cover.
=86. CIRCUIT BREAKER AND TIMER ASSEMBLY= (figs. 50 and 51).
=a.= When the circuit breaker timer shaft and base assembly must be
replaced due to excessive wear in timer shaft bearing, sheared worm
gear pin, and/or worn or damaged worm gear, engine ignition must be
retimed. Ignition timing for the V‐type twin engine is difficult and
should be attempted only by experienced personnel.
=b. Remove= (fig. 50). Before the timer shaft and base assembly can
be removed, the circuit breaker timer head assembly must be removed.
NOTE: _If the timer head only, or timer wire, is to be replaced, it is
not necessary to remove timer shaft and base assembly, and thus throw
engine ignition out of time._
(1) Remove timer head cover.
(2) Unlatch cover retainer ends from holes in the timer head and remove.
(3) Disconnect spark control wire at timer lever.
(4) Lift the timer head assembly off base. The head seating tension
(ground) spring (underneath shaft base) is also free, and can now be
removed. NOTE: _It is not necessary to disconnect timer to coil wire
from timer head terminal post, unless head or wire is being replaced._
(5) Remove the two timer base mounting screws and lock washers. It will
be noted that one screw grounds the timer to coil wire shielding.
(6) Timer shaft and base assembly can now be lifted out of engine gear
case cover. Take care not to damage or misplace base gasket.
=c. Install Timer Shaft and Base Assembly and Timing Ignition=
(fig. 51). This calls for retiming engine ignition as follows: (NOTE:
_Circuit breaker cam turns in clockwise direction_):
(1) Unscrew and raise front cylinder inlet valve spring cover, using
tappet wrench (41-W-3617).
(2) Turn engine in direction in which it runs until valve tappet
indicates front cylinder is on compression stroke (directly after front
cylinder intake valve closes).
[Illustration:
=A=—FLYWHEEL TIMING MARK IN CRANKCASE INSPECTION HOLE.
=B=—COVER RETAINER.
=C=—CIRCUIT BREAKER LEVER.
=D=—CIRCUIT BREAKER CAM.
=E=—CONDENSER.
=F=—SPARK CONTROL WIRE HOUSING.
=G=—SPARK CONTROL WIRE.
=H=—SPARK LEVER QUADRANT.
=J=—SPARK LEVER.
=K=—TIMER HEAD ADJUSTING BAND SCREW.
=L=—TIMER HEAD ADJUSTING BAND.
=M=—MARK ON BREAKER CAM AND MARKS ON TIMER HEAD AND HAND
INDICATING ORIGINAL FACTORY TIMING.
=N=—CIRCUIT BREAKER POINTS.
=O=—ADJUSTABLE CONTACT POINT PLATE.
=P=—ADJUSTABLE CONTACT POINT LOCK SCREWS.
=Q=—CIRCUIT BREAKER LEVER PIVOT (INSULATED).
=R=—BREAKER LEVER SPRING.
RA PD 310281
_Figure 51—Circuit Breaker Marks and Flywheel Mark Correctly Alined_]
(3) Remove plug from timing inspection hole in left‐side crankcase.
(4) Continue turning engine slowly until flywheel timing mark is in
center of inspection hole (fig. 51). Do not turn engine further.
(5) Install paper gasket and timer head tension (ground) spring on
timer shaft base assembly. Make sure bent ends of tension spring are
facing downward (away from timer base).
(6) Insert timer shaft and base assembly all the way down into place in
timing gear case cover, trying to locate mark on small end of breaker
cam in position shown in figure 51. Do not install base mounting screws
as yet.
(7) Install timer head assembly so that spark control lever is within
the advance and retard quadrant (fig. 51). NOTE: _Do not install cover
retainer until later._
(8) Fully advance spark lever (push inward toward engine) and observe
how closely mark on breaker cam lines up with breaker lever fiber.
If mark does not line up, lift timer base and turn shaft gear so its
engagement with its driving gear is changed one tooth. Check again
according to breaker cam mark and breaker lever fiber. Repeat this
procedure until gear engagement is obtained which closely alines cam
mark and breaker lever fiber.
(9) See that timer base is turned so that timer to coil wire is toward
rear of engine.
(10) Install timer base screws and lock washers. Make sure that timer
to coil wire shielding is grounded under head of screw farthest away
from engine (fig. 52). Securely tighten screws.
(11) Install timer head on base and secure with ground spring and cover
retainer. Be sure ground spring is in its proper place so that when
cover retainer ends are fitted through holes in the timer head, they
will also fit into spring locating notches. It will be necessary to
press ground spring upward under timer base to engage retainer ends
in the spring notches. NOTE: _If cover retainer ends do not engage
ground spring notches, spring will have no tension and timer head
will be loose on its base._ Circuit breaker points and condenser are
electrically grounded through timer base, and ground spring holds the
head and base in close contact, thus assuring a good ground.
(12) Connect spark control wire and timer lever and adjust (par. 88).
(13) Engine is now timed according to original factory setting,
providing mark on side of timer head and hole in head adjusting band
are still in alinement, and circuit breaker point gap is 0.022 inch.
Even though all ignition timing marks are in perfect alinement, as
outlined in the foregoing instructions, it is advisable to accurately
check ignition timing (step =d= following).
=d. Recommended Recheck of Ignition Timing= (fig. 51). Even though
all ignition timing marks are in perfect alinement, as when engine was
originally timed, ignition timing may change somewhat after engine has
been in service for a while, due to normal wear and seating of the
various moving parts that can affect ignition timing. Since accurate
ignition timing is the first essential to good engine performance, it
is advisable to check ignition timing on new vehicle after first 1,500
miles of service, and at each 2,000 miles thereafter.
(1) See that circuit breaker points are adjusted for correct gap of
0.022 inch (par. 84 =f=).
(2) Advance timer lever fully (toward engine).
(3) Turn engine in direction in which it runs until front cylinder
is on compression stroke, and continue to turn it ahead slowly until
narrow timer cam (the end with the timing mark), just starts to open
the circuit breaker points.
[Illustration: RA PD 318205
_Figure 52—Shielding of Coil to Timer Wire Grounded on Base_]
(4) An accurate test light check as to when points just start to break
can be made, using the instrument panel red light for the purpose.
Disconnect panel light wire from the oil pressure switch, attaching
this wire to the insulated terminal post on timer head. Turn ignition
and light switch on. As long as circuit breaker points are closed,
lamp will remain lit; as points start to open, lamp will go out. NOTE:
_After making use of instrument panel red light for above purpose,
reconnect wire to oil pressure switch._
(5) When exact position is found, where points just start to open,
flywheel mark should be in the center of the inspection hole.
(6) If flywheel mark is not in center of hole when points open,
readjust ignition timing as necessary (slower or faster) by means of
the timer head and band adjustment.
[Illustration: RA PD 318203
_Figure 53—Shielded Coil to Timer Wire Correctly Connected at Coil_]
(7) To readjust timer head, loosen adjusting band screw and shift
timer head in band. If flywheel timing mark shows forward of center
in inspection hole, the timing is slow. To correct, shift timer head
counterclockwise against rotation of breaker cam. If flywheel mark is
to rear of center of inspection hole, timing is fast and timer head
must be shifted with rotation (clockwise) of breaker cam, to correct
timing.
(8) With ignition timing correct, front cylinder piston is 9/32 inch
before top dead center, on compression stroke, when circuit breaker
points just start to open. At this point spark occurs, igniting front
cylinder fuel charge.
(9) Install flywheel inspection hole plug in left crankcase.
=87. COIL TO TIMER WIRE= (figs. 52 and 53).
=a.= Models provided with radio shielding are identified by “S” on
either side of instrument panel. The coil to timer wire (low‐tension
wire) on these models is shielded for radio noise suppression.
=b. Remove.=
(1) Disconnect battery negative ground wire at frame connection.
(2) Remove the two bolts which secure upper end of air cleaner bracket
to frame tube. Swing air cleaner and bracket outward and forward to
gain access to spark coil rear terminal.
(3) Disconnect coil to timer wire terminal from coil rear connection.
Disconnect wire shielding from coil rear ground connection.
(4) Refer to paragraph 86 =b= (1) to (4) for timer head removal.
(5) Remove timer base mounting screw which secures wire shielding (fig.
52).
(6) Note position of coil to timer wire inside of timer head; then
remove nut washer connecting wire to insulated contact stud.
(7) Work old wire and loom out of timer head hole and free from vehicle.
(8) On earlier models, the coil to timer wire was soldered to end of
insulated stud. Removal of stud is necessary to remove this wire, or
replace it with a shielded wire. Note location of stud insulations
on inside and outside of timer head, for correct installation when
reassembling.
=c. Install.=
(1) Pass end of wire, shield terminal, and loom up through hole in
timer base.
(2) Ground the wire shield terminal under head of timer base mounting
screw (fig. 52).
(3) Connect wire end terminal to insulated stud so that wire leads away
from stud in direction shown (fig. 52).
(4) Pass coil to timer wire up alongside and to rear of frame saddle
post tube to reach rear of spark coil.
(5) Ground the wire shield terminal to coil rear ground connection
(fig. 53).
(6) Connect wire terminal to coil rear primary connection (fig. 53).
(7) Install timer head on base (par. 86 =c= (11)).
(8) Connect spark control wire to timer lever and adjust (par. 88).
(9) Connect battery negative post wire to frame ground terminal.
(10) Swing air cleaner bracket back into place and install two bolts,
washers, and nuts securing bracket to frame clips.
(11) Replace timer cover and check engine for starting.
88. ADJUST SPARK CONTROL.
=a.= Spark advance and retard is controlled by left handle bar grip.
Spark lever operates within a quadrant mounted on engine. Spark must
be fully advanced (lever inward toward engine) when handle bar grip is
turned inward to full extent of its travel. When handle bar grip is
turned outward, spark lever retards (lever outward away from engine).
(1) With control wire in lever stud and clamp screw loose, turn left
grip fully inward; then back it out just a little.
(2) Shift spark lever inward toward engine as far as it will go; then
tighten control wire clamp screw. Test by turning left grip fully
inward and noting position of spark lever. It should be against inner
side of quadrant (fig. 51). Retard spark and check position of lever
within quadrant; it should be against outer side of quadrant.
(3) Check final adjustment. Readjust full advance and retard timer
lever positions as necessary when left grip is turned inward, and
outward, respectively.
=89. SPARK COIL= (fig. 54).
=a.= Spark coil high‐tension cables go directly to the spark plugs, no
distributor being used. When the coil is faulty, it must be replaced,
since internal repairs are not possible. The high‐tension cables can be
replaced, however. Coil is provided with a condenser for radio noise
suppression, and metal coil case is grounded to engine by bonding.
=b. Remove.=
(1) Disconnect battery negative ground wire from frame connection.
(2) Free high‐tension cable ends (with radio noise suppressors) from
spark plugs. Free front cylinder high‐tension cable from clip at upper
engine frame mounting.
(3) Loosen air intake hose connection at carburetor fitting.
(4) Remove two nuts, washers, and bolts securing upper end of air
cleaner mounting bracket to frame clamps.
[Illustration: RA PD 318204
_Figure 54—Coil Front Connections Showing Radio Bonding and Noise
Suppression Condenser_]
(5) Swing air cleaner and bracket assembly outward to gain access to
coil rear terminals.
(6) Disconnect coil to timer wire from coil rear terminal screw.
Disconnect wire shielding from coil rear ground terminal (fig. 53).
(7) Swing cleaner back and remove wire connections from coil front
terminal screw (fig. 54).
(8) Disconnect radio bonding at coil front ground terminal (fig. 54).
(9) Remove nuts and bolts which mount coil to bracket. Coil is now free
for removal.
=c. Install.=
(1) Mount coil on frame bracket with high‐tension cables upward, and
reinstall mounting bolts, lock washers, and nuts. Tighten nuts.
(2) Connect terminals of the two green wires to coil front terminal
screw. Refer to wiring diagram, figure 48.
(3) Connect radio bonding to coil front ground terminal. Tighten nut
securely.
(4) Connect coil to timer wire terminal to coil rear terminal screw.
Connect wire shielding to coil rear ground terminal. Tighten nut
securely.
(5) Swing air cleaner and bracket assembly back in place and install
two bolts, lock washers, and nuts securing bracket to frame clamps.
Tighten nuts securely.
(6) Connect battery negative ground wire to frame connection.
(7) Pass front cylinder high‐tension wire under tank, secure in cable
clip at upper engine frame mounting, and attach cable end (radio noise
suppressor) to front spark plug. Attach rear high‐tension cable end
(radio noise suppressor) to rear spark plug.
(8) Check wiring connections (fig. 48) and test coil by engine
starting.