October 28, 1960
Bulletin No. SB-805
Synchronizing Mag.& Carb.
SUBJECT: Location of timing marks on modified magneto mounting brackets;
75 H.P. models V4S & V4SL-12 thru 13
Figure 1
The magneto mounting bracket for the subject engine
models has been modified to the extent of adding a
mounting pad, (figure 1, letter 'A'). Although the
timing mark's location remains in its original
position, the pad makes the timing mark difficult to
see when mounted as a complete unit on the engine.
For this reason the mark has been extended onto the
mounting pad so it will be more readily visible for
synchronizing magneto and carburetor, (figure 2,
letter B). The timing marks must, as in the past,
be in line for synchronizing purposes which is
accomplished exactly as before, and as instructed
in service bulletin No. SB-739. The synchronizing
procedure has not been changed by the addition of the
mounting pad.
Figure 2
Align marks A, B & C as instructed
in service bulletin #SB-739.
75 H.P. production engine models V4S & V4SL-12 & 12S
through the first few 1961 models V4S & V4SL-13 were
built using the bracket illustrated in figure 1.
Subsequent engines use the bracket illustrated in
figure 2.
All 1961 V4S & V4SL-13 engines have utilized the pad
to mount a safety switch as shown in figure 3. On
these engines the switch plunger conceals the timing
mark on the pad; but timing is accomplished by
aligning the timing mark on the pulley with the
center of the plunger as illustrated by the arrow in
figure 3.
Figure 3
Align pulley’s timing mark with
center of plunger on 1961 models
V4S & V4SL-13.
JOHNSON MOTORS
W. W. DeWees
Service Department
WWD:eb
NOTE: Post on your V4 index - 75 H.P.