Mercury 40 Service Manual

IGNITION
Page 2A-12 90-828631R3 MARCH 1999
Ignition Troubleshooting
WARNING
DANGER - HIGH VOLTAGE/SHOCK HAZARD! Do not touch ignition components
and/or metal test probes while engine is running and/or being “cranked”. STAY
CLEAR OF SPARK PLUG LEADS. To assure personal safety, each individual spark
plug lead should be grounded to engine.
WARNING
When testing or servicing the ignition system, high voltage is present. DO NOT
TOUCH OR DISCONNECT any ignition parts while engine is running.
Tool: Multimeter/DVA Tester 91-99750A1
Component
Test
Selector Switch
Position
DVA Lead
Red
DVA Lead
Black
Voltage Reading
(1)
@300-3000 RPM
Coil
Primary
400 DVA*
Coil (–) Black (B)
Lead
(2) **
Coil (+) Orange
(O) Lead
(2) **
160 - 280 (1)
Stator Charge Coil 400 DVA* Brown (Br) Lead (2) Ground 160 - 280 (1)
(CDI) Unit
Stop Circuit
20 DVA
(CDI) Unit
White (W) Lead
(2)
Ground 3 - 7
* If using a meter that requires a DVA adapter, place selector switch to the 400 VDC position.
** Reverse Polarity
(1) Readings may vary at cranking speed or at idle speed.
(2) Back probe the electrical lead bullet connector in order to make connection.
Multimeter Ohm Checks
Tested Part Multimeter Wires Connected To: Meter Scale Meter Reading
Stator Charge Coil
Red
Black
Blue (2)
Brown (1)
R x 1 Ω 272 - 408
Trigger Coil
Red
Black
White/Red (1)
White/Blk (2)
R x 1 Ω 396 - 594
Ignition Coil Primary
(with wires
disconnected)
Red
Black
Orange (O)
Black (B)
R x 1 Ω 0.1 - 0.7
Ignition Coil Secondary
(test with coil leads dis-
connected and the
high tension lead cap
removed)***
Red
Black
High Tension Lead
#1
High Tension Lead
#2
k Ω 3.5 - 5.2
NOTE: Copper is an excellent conductor, however, resistance may notably vary between
low and high temperature. Therefore, reasonable differences can be accepted between
resistance readings and specifications. The above readings are for a cold (room tempera-
ture) engine. Resistance will increase if the engine is warm.
*** High tension lead cap contain a 5k ohm resister. Remove caps when making secondary
ignition coil test.

Mercury 40 Specifications

General

Brand	Mercury
Model	40
Category	Outboard Motor
Language	English