Mercury 90 Operation Maintenance Installation Warranty Manual

• Ignition system component failure.
Performance Loss
POSSIBLE CAUSES
• Overheating ‑ Warning horn not working.
• Low oil pressure. Check oil level.
• Throttle not opening fully.
• Damaged propeller or improper propeller size.
• Incorrect engine timing, adjustment, or setup.
• Boat overloaded or load improperly distributed.
• Excessive water in bilge.
• Boat bottom is dirty or damaged.
Battery Will Not Hold Charge
POSSIBLE CAUSES
• Battery connections are loose or corroded.
• Low electrolyte level in battery.
• Worn out or inefficient battery.
• Excessive use of electrical accessories.
• Defective rectifier, alternator, or voltage regulator.
• Open circuit in the alternator output wire (fused link).
TROUBLESHOOTING
eng 91

Mercury 90 Specifications

General

Brand	Mercury
Model	90
Category	Outboard Motor
Language	English