Yamaha F50D Servise Manual - page 102

Electrical system

5-13

ELEC

TIP:

9

Do not remove the clip from the engine

shut-off switch.

9

Repeat step 2–step 3 for each spark plug

cap.

Checking the spark plug cap

1.

Remove the spark plug caps from the

spark plug wires by turning the caps

counterclockwise.

2.

Measure the spark plug cap resistance.

Replace if out of specification.

Checking the ignition coil

1.

Disconnect the ignition coil connector

and terminal.

2.

Remove the spark plug caps from the

spark plug wires by turning the caps

counterclockwise.

3.

Measure the ignition coil resistance.

Replace if out of specification.

4.

Install the spark plug caps to the spark

plug wires by turning the caps clockwise,

and then connect the ignition coil con-

nector and terminal.

Checking the pulser coil

1.

Disconnect the pulser coil coupler 

a

,

and then connect the test harness 

1

.

2.

Measure the pulser coil output peak volt-

age. Check the pulser coil air gap if

below specification. See “Checking the

pulser coil air gap” (7-2).

Spark plug cap resistance 

(reference data):

3.8–6.3 k

Ω

at 20 °C (68 °F)

1

Ignition coil resistance (reference data):

Primary coil:

Orange (O)–Black (B)

0.1–0.2 

Ω

 at 20 °C (68 °F)

Secondary coil:

Spark plug wire–Spark plug wire

3.5–4.7 k

Ω

 at 20 °C (68 °F)

Test harness (2 pins) 

1

: 90890-06867

B

O