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.
Two main types of used outboard engines will be found: two stroke and four stroke outboards.
A two stroke outboard is simpler and lighter than a four stroke. However, you have to mix a special type of oil with the petrol in order to lubricate the engine. This oil gets burned along with the petrol and produces more exhaust gases, pollution and noise than a four stroke which has a separate oil circulation system like that of a car engine. Consequently, the sale of new two stroke outboards of the original design has been banned and most new ones are four stroke.
You will, though, find plenty of second-hand two stroke outboards legally for sale. As well as choosing the appropriate horse power to match the length, shape, type and weight of boat, you need to consider the weight of the used outboard engine and whether you can lift it on and off the boat.
Starting an outboard with a pull cord requires some effort. However, many larger outboards have an electrical starting system which may be preferable – although more complicated to install.
Running costs will depend on whether you will use a small motor for slow cruising along inland waterways or a powerful one for high speeds at sea. High speed uses fuel very rapidly.
Ask at the local marine engineer about the cost of servicing particular used outboard engines and check that spare parts and servicing manuals are still available – particularly if you will do some of the servicing yourself.