March 28, 1962
Bulletin No. SB-888 (Revised)
Flywheels - Magneto
SUBJECT: Three-piece flywheels on early 1962 - 40 h.p. engines.
Early 1962 - 40 h.p. engines were built with
flywheel assemblies which consisted of three
(3) basic components, i.e., flywheel, spacer
and ring, or ring gear. Figure 1 illustrates
the three components for an electric starting
model. Manual starting engines use a similar
assembly, but do not contain a generator pull-
ey, and substitute a ring for a ring gear.
The spacer was used on the early 1962 -
40 h.p. engines to add mass to the flywheel
for the purpose of improving motor per-
formance in both the idle and operating
rpm ranges. Later 1962 models use rings
or ring gears which are made heavier than
previous units, and thus eliminate the
necessity for a spacer. NEITHER THE SPACER
NOR THE NEW RING, OR RING GEAR, CAN BE USED
ON PRODUCTION RD MODEL SERIES PRIOR TO 1962.
When assembling the components of both the three-piece and two-piece flywheel assemblies,
screw number 309059 must be used because of the increased depth provided by the spacer, the
new rings and the new ring gears.
The illustrated spacer is not available as a service part. As a result there are several
precautions to be observed whenever the component parts of the three-piece flywheels
require replacement. It is consequently necessary to service component parts as follows:
1. FLYWHEELS ONLY. Replace as follows:
a. Manual and electric starting engines - use 580410 Flywheel less ring gear.
2. SPACERS (not serviced). If the spacer cannot be reused for some reason, discard
it along with the ring or ring gear, and replace both components as follows:
a. Manual starting engines - use 1 piece 308853 ring;
b. Electric starting engines - use 1 piece 308852 ring gear.
3. RINGS OR RING GEARS. When only these parts need replacement, discard the spacer
(it cannot be used with the parts specified here), and replace both components
as follows:
a. Manual starting engines - use 1 piece 308853 ring;
b. Electric starting engines - use 1 piece 308852 ring gear.
4. COMPLETE FLYWHEEL ASSEMBLIES. When required, service as follows:
a. Manual starting engines - use 580413 Flywheel assy. complete.
b. Electric starting engines - use 580412 Flywheel assy. complete.
over