Record these numbers in the
Quick Reference
Data
section at the front of the book. Have these
numbers available when ordering parts. If neces-
sary, use
Table 1
and
Table 2
to identify a particular
motorcycle.
FASTENERS
Proper fastener selection and installation is im-
portant to ensure that the vehicle operates as de-
signed and can be serviced efficiently. Original
equipment fasteners are designed for their specific
applications. Make sure replacement fasteners meet
all the same requirements as the originals.
Threaded Fasteners
Threaded fasteners secure most of the compo-
nents on the vehicle. Most are tightened by turning
them clockwise (right-hand threads). If the normal
rotation of the component would loosen the fas-
tener, it may have left-hand threads. If a left-hand
threaded fastener is used, it is noted in the text.
Two dimensions are required to match the thread
size of the fastener: the number of threads in a given
distance and the outside diameter of the threads.
Two systems are currently used to specify
threaded fastener dimensions: the U.S. standard
system and the metric system (
Figure 5
). Pay par-
ticular attention when working with unidentified
fasteners. Mismatching thread types can damage
threads.
CAUTION
To ensure the fastener threads are not
mismatched or cross threaded, start
all fasteners by hand. If a fastener is
hard to start or turn, determine the
cause before tightening it with a
wrench.
The length (L,
Figure 6
), diameter (D) and dis-
tance between thread crests (pitch) (T) classify met-
ric screws and bolts. A typical bolt may be
identified by the numbers, 8—1.25 × 130. This in-
dicates the bolt has diameter of 8 mm, the distance
between thread crests is 1.25 mm and the length is
130 mm. Always measure bolt length as shown in
Figure 6
to avoid purchasing replacements of the
wrong length.
The numbers located on the top of the fastener
(
Figure 6
) indicate the strength of metric screws
and bolts. The higher the number, the stronger the
fastener. Unnumbered fasteners are the weakest.
Many bolts and studs are combined with nuts to
secure particular components. To indicate the size
of a nut, manufacturers specify the internal diame-
ter and the thread pitch.
The measurement across two parallel flats on a
nut or bolt head indicates the wrench size that fits
the fastener.
4
CHAPTER ONE
2
3
4
