Electrical System Fundamentals; Cylinder Bore Gauge; Compression Gauge; Multimeter - Yamaha V star 1100 Owner's Manual

GENERAL INFORMATION
37
38
39
mounting bases: magnetic, clamp, or screw-in stud.
When purchasing a dial indicator, select the mag-
netic stand type (B, Figure 36) with a continuous
dial.

Cylinder Bore Gauge

A cylinder bore gauge is similar to a dial indica-
tor. The gauge set shown in Figure 37 consists of a
dial indicator, handle, and different length adapters
(anvils) to fit the gauge to various bore sizes. The
bore gauge is used to measure bore size, taper and
out-of-round. When using a bore gauge, follow the
manufacturer's instructions.

Compression Gauge

A compression gauge (Figure 38) measures com-
bustion chamber (cylinder) pressure, usually in psi
2
or kg/cm . The gauge adapter is either inserted or
screwed into the spark plug hole to obtain the read-
ing. Disable the engine so it will not start and hold
the throttle in the wide-open position when per-
forming a compression test. An engine that does not
have adequate compression cannot be properly
tuned. See Chapter Three.

Multimeter

A multimeter (Figure 39) is an essential tool for
electrical system diagnosis. The voltage function
indicates the voltage applied or available to various
electrical components. The ohmmeter function tests
circuits for continuity and measures the resistance
of a circuit.
Some test specifications for electrical compo-
nents are based on results using a specific test meter.
Results may vary if a meter not recommend by the
manufacturer is used. Such requirements are noted
when applicable.
Ohmmeter (analog) calibration
Each time an analog ohmmeter is used or if the
scale is changed, the ohmmeter must be calibrated.
Digital ohmmeters do not require calibration.
1. Make sure the meter battery is in good condition.
2. Make sure the meter probes are in good condi-
tion.
3. Touch the two probes together and watch the
needle. It should align with the 0 mark on the scale.
4. If necessary, rotate the set-adjust knob until the
needle points directly to the 0 mark.
ELECTRICAL SYSTEM
FUNDAMENTALS
A thorough study of the many types of electrical
systems used in today's vehicles is beyond the
scope of this manual. However, an understanding of
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