As there are hundreds of makes, models, types and sizes of outboard boat engines, the following are some useful general points which apply to many motors. However, it is most important to follow all the safety advice, operating instructions and maintenance instructions in manuals and handbooks provided by the manufacturer for your particular motor. Check also your boat insurance policy for rules concerning maintenance. It may specify that some types of maintenance must be carried out by a qualified engineer.
Visit the website of manufacturers for details and discuss aspects you are unsure of with outboard dealers/engineers. Handbooks and detailed workshop manuals can be purchased at most chandlers and from websites.
Please note that this is an introduction to using the outboard motor effectively and safely.
Petrol gives off a highly inflammable, heavy explosive vapour which can accumulate in the bilges of a boat. Always fill the tank away from the boat where vapour cannot accumulate and clear of any source of ignition. Have a fire extinguisher handy. For a two stroke motor, mix the correct type of oil with petrol in the ratio indicated on a label on the outboard boat engine or in its handbook. Don’t make the mistake of assuming the ratio is the same as that for someone else’s motor. An oil/fuel ratio of 1:50 applies to many outboards but can vary from 1:10 for the oldest to 1:200 for the most recent models. A four stroke motor has a separate oil circulation system so does not need oil added to the fuel. Check the level using the dip stick.
Always have a rope tied to the outboard boat engine and the boat to stop it dropping overboard if the clamp loosens. Having connected the fuel line, open the air vent on the fuel tank and squeeze the primer bulb several times. Before pulling the starter cord, check nothing is on or near the propeller and the gear is in neutral. Use the choke briefly if the motor is cold. Adjust the controls to the ‘start’ position. Pull the starter cord slowly until resistance is felt then pull firmly and quite hard. The motor should start with a few pulls.
With internet now widely accessible worldwide it has become common to find and order used outboards from specialist shops with just a few clicks of a mouse. Such purchases prove to be safe and money/time saving and the outboards are professionally maintained/tested before being sold and come with different kinds of warranty.
If you don't want to risk buying a used outboard from a private seller, I would recommend visiting such well established specialists as hardcoremarine.com (for US), casse-marine.com (for France and Mediterranean), outboards-direct.co.uk or avondale-marine.com (worldwide).
If, however, you cannot find an outboard you need from a specialist and are planning to buy one from a private seller, you need to be extra careful and inspect it inside and out before purchasing. If you are unsure, seek advise from an engineer, as buying privately offers no guarantees and could result in unexpected expenditures rectifying technical faults.