SERVICE MANUAL NUMBER 26
IGNITION SYSTEM
Description
EST or Electronic Spark Timing is a High Energy Ignition System (HEI). The distributor itself
has no centrifugal advance mechanism or devices.
The spark plug wires are a carbon-impregnated cord conductor with a silicone rubber jacket.
It is important they be handled with care, and routed so as not to cross each other or to be
in contact with other parts of the engine to prevent rubbing.
The EST System uses a square coil with epoxy covered windings to protect against mois-
ture and arc-over.
The timing cannot be set the same way that other ignition systems were.
b
c
e
d
a
f
70106
a - Distributor with Spark Plug Wires
b - Wires (WHITE) Used in Timing Procedure
c - Wire from Shift Interrupt Switch
d - Distributor Harness
e - Engine Harness Wire (PURPLE AND GRAY)
f - Coil
EST uses a magnetic pulse generator and an electronic module to primary circuit current.
Internally the Pulse Generator, or magnetic pick-up assembly, takes the place of conven-
tional points. A timer core on the main shaft of the distributor has external teeth which align
with an equal number of pole piece teeth (four for a four cylinder engine). The electronic
module is small enough to allow it to be mounted inside the distributor, and contains the cir-
cuits necessary for dwell control and advance of the timing.
Index
90-861329--1
MARCH 1999
Page 4B-5
| Categories | Mercury MerCruiser Manuals |
|---|---|
| Tags | Mercury MerCruiser 181 CID |
| Model Year | 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 |
| Download File |
|
| Document File Type | |
| Copyright | Attribution Non-commercial |
(6 votes, average: 5 out of 5)
Marine readers have rated Mercury MerCruiser GM 4 Cylinder 181 cid 3.0L Marine Engines Service Manual Number 26 5.0 out of 5.0 based on 6 product reviews. Thanks for sharing this material. Helps a lot after suffering with bad mechanics. spend too much money and nothing very good
great manual, makes impossible jobs possible. without a manual you can not do the job, a must have.
Great resource. Excellent information provided.
Need help to install automate choke
Need help to instal automate choke