SERVICE MANUAL NUMBER 26
TROUBLESHOOTING
Radio Noise
Cause
Special Information
Ignition System - wrong spark plugs;
cracked distributor cap; cracked coil tower;
leaking spark plug wires; moisture on
ignition components
A popping noise that will increase with
engine rpm. Noise will stop as soon as
engine is turned off.
Alternator - poor brush contact on the slip
rings
High pitched whine in the radio
Instrumentation - loose connections or
antennae wire routed too close to
instruments
A hissing or crackling noise when
instruments are jarred with ignition on
Accessories - bilge pump, bilge blower;
fish finder; depth locator; cabin heater
motor, etc. Disconnect one at a time until
noise disappears.
Varying unexplained noises
Troubleshooting With Vacuum Gauge
Reading
Cause
Steady reading between 15-21 inches at
idle rpm
Normal
Extremely low reading, but steady at idle
rpm
Vacuum leak; incorrect timing;
underpowered boat; faulty boat bottom
Fluctuates between high and low at idle
rpm
Blown head gasket between two adjacent
cylinders
Fluctuates 4 or 5 inches very slowly at idle Carburetor needs adjustment; spark plug
rpm
gap too narrow; valves are sticking
Fluctuates rapidly at idle, steadies as rpm
is increased
Valve guides are worn
Continuously fluctuates between low and
normal reading at regular intervals at idle
rpm
Burned or leaking valve
Miscellaneous
Cause
Special Information
Low grade or stale fuel
Water in fuel
Index
90-861329--1
MARCH 1999
Page 1C-21
| 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