Mercury Mariner 30/40 4-Stroke Outboard Service Manual 1998, Page 16Get this manual
MAINTENANCE
Inspection And Maintenance Schedule
To keep your outboard in the best operating conditionit is important that your outboard receive the periodic inspections and maintenance listed in the Inspection and Maintenance ScheduleWe urge you to keep it maintained properly to ensure the safety of you and your passengers and retain its dependability
Neglected Inspection and maintenance service of your outboard or attempting to perform maintenance or repair on your outboard if you are not familiar with the correct service and safety procedures could cause personal injury, death, or product failure