SERVICE MANUAL NUMBER 24
TROUBLESHOOTING
IMPORTANT INFORMATION
Section 1C - Troubleshooting
1
C
Table of Contents
Used Spark Plug Analysis . . . . . . . . . . . .
Normal Condition . . . . . . . . . . . . . . . . .
Chipped Insulator . . . . . . . . . . . . . . . . .
Wet Fouling (Oil Deposits) . . . . . . . . .
Cold Fouling . . . . . . . . . . . . . . . . . . . . .
Overheating . . . . . . . . . . . . . . . . . . . . .
High Speed Glazing . . . . . . . . . . . . . . .
Scavenger Deposits . . . . . . . . . . . . . .
Pre-Ignition Damage . . . . . . . . . . . . . .
Reversed Coil Polarity . . . . . . . . . . . . .
Splashed Deposits . . . . . . . . . . . . . . . .
Mechanical Damage . . . . . . . . . . . . . .
Poor Boat Performance and/or
1C-2
1C-2
1C-2
1C-3
1C-3
1C-3
1C-4
1C-4
1C-4
1C-5
1C-5
1C-5
Engine Runs Poorly At High RPM . . . . . 1C-16
Engine Acceleration Is Poor . . . . . . . . . . 1C-17
Troubleshooting with Vacuum Gauge . . 1C-17
Engine Noise . . . . . . . . . . . . . . . . . . . . . . . 1C-18
Important Information . . . . . . . . . . . . . 1C-18
Valve Cover Area . . . . . . . . . . . . . . . . . 1C-18
Cylinder Area . . . . . . . . . . . . . . . . . . . . 1C-19
Camshaft Area . . . . . . . . . . . . . . . . . . . 1C-19
Crankshaft Area . . . . . . . . . . . . . . . . . . 1C-20
Miscellaneous . . . . . . . . . . . . . . . . . . . . 1C-21
Oil Pressure . . . . . . . . . . . . . . . . . . . . . . . . 1C-22
Low Oil Pressure . . . . . . . . . . . . . . . . . 1C-23
High Oil Pressure . . . . . . . . . . . . . . . . . 1C-23
Excessive Oil Consumption . . . . . . . . . . . 1C-24
Water In Engine . . . . . . . . . . . . . . . . . . . . . 1C-25
Important Information . . . . . . . . . . . . . 1C-25
Water on Top of Pistons . . . . . . . . . . . 1C-26
Water in Crankcase Oil . . . . . . . . . . . . 1C-26
Engine Overheats (Mechanical) . . . . . . . 1C-27
Engine Overheats (Cooling System) . . . 1C-28
Insufficient Water Flow from Belt
Poor Maneuverability . . . . . . . . . . . . . . . .
Improper Full Throttle Engine RPM . . . .
RPM Too High . . . . . . . . . . . . . . . . . . .
RPM Too Low . . . . . . . . . . . . . . . . . . . .
Engine Cranks Over but Will Not
1C-6
1C-7
1C-7
1C-7
Start or Starts Hard . . . . . . . . . . . . . . . . .
Important Information . . . . . . . . . . . . .
Testing Thunderbolt V
1C-8
1C-8
Ignition System . . . . . . . . . . . . . . . . . .
1C-9
Driven Seawater Pickup Pump . . . . . 1C-29
Power Steering . . . . . . . . . . . . . . . . . . . . . 1C-30
Poor, Erratic, or No Assist . . . . . . . . . 1C-30
Noisy Pump . . . . . . . . . . . . . . . . . . . . . . 1C-31
Fluid Leaks . . . . . . . . . . . . . . . . . . . . . . 1C-31
Troubleshooting Silent Choice
Fuel System Rich . . . . . . . . . . . . . . . . . 1C-10
Fuel System Lean . . . . . . . . . . . . . . . . 1C-10
Miscellaneous . . . . . . . . . . . . . . . . . . . . 1C-10
Engine Will Not Crank Over . . . . . . . . . . .
Charging System Inoperative . . . . . . . . .
1C-11
1C-11
Noisy Alternator . . . . . . . . . . . . . . . . . . . . . 1C-12
Instrumentation Malfunction . . . . . . . . . . 1C-12
Radio Noise . . . . . . . . . . . . . . . . . . . . . . . . 1C-12
Poor Fuel Economy . . . . . . . . . . . . . . . . . 1C-13
Carburetor Malfunctions . . . . . . . . . . . . . . 1C-14
Engine Runs Poorly at Idle . . . . . . . . . . . 1C-15
Exhaust Silencer System . . . . . . . . . . . . 1C-32
Compressor Will Not Run - Testing
Mode Switch . . . . . . . . . . . . . . . . . . . . 1C-33
Compressor Will Not Run - Testing
Air Pump . . . . . . . . . . . . . . . . . . . . . . . . 1C-33
Air Pump Runs - System Inoperative
1C-33
Index
90-861327--1
OCTOBER 1999
Page 1C-1
| Categories | Mercury MerCruiser Manuals |
|---|---|
| Tags | Mercury MerCruiser 305 CID, Mercury MerCruiser 350 CID |
| Model Year | 1998, 1999, 2000, 2001 |
| Download File |
|
| Document File Type | |
| Copyright | Attribution Non-commercial |
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Marine readers have rated Mercury MerCruiser Engines Service Manual Number 24 GM V-8 305 CID 350 CID 4.0 out of 4.0 based on 1 product reviews. Great performance engine.
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