If you’re in the market for a second-hand powerboat or outboard only, it’s a good idea to arrange a pre-purchase inspection from a qualified mechanic. But before you do, there are some checks you can do first.
1. Make sure you can start the outboard and it idles smoothly.
2. Check the controls aren’t seized. Likewise, check steering isn’t seized by turning lock to lock.
3. Inspect battery and cables; test all electronics.
4. Inspect fuel lines and fittings, squeeze primer bulb till firm, while checking for leaks.
5. Check under the cover of motor, looking for fire damage inside cowling.
6. Inspect all gaskets around cylinder head and exhaust plates for corrosion.
7. Tilt motor up to inspect engine mounts, swivel points and propeller for wear and tear.
8. Run the motor and place your hand on the cylinder head and exhaust plates. They should feel very warm, not hot to touch.
Once you've performed these checks you can me pretty confident that the motor is sound. However there are additional checks that should be carried out by a mechanic before you buy.