This post is also available in: Italiano (Italian)

Outboards can be divided into two wide families: portable outboards, whose power ranges between 2.5 and 15 hp, and those affixed to the vessel. These latter have higher power and weight and are usually linked to electronic controls.

Portable outboards are simpler and are used for dinghies and small vessels: they undergo basic routine and seasonal servicing.

Starting from the outside, you can see the engine housing on the powerhead and the shaft, called leg, which ends with the propeller and a protection skeg.

Change the oil of the drive every season, or every other if you use the engine little. To do so, warm up the engine first: prepare a tank with fresh water and vinegar, start the engine inside it and engage the gear. This simple mix will clean the cooling system and descale the channels. Make sure that the outflow of the cooling system is powerful.

The most important part of the cooling system is the impeller, fitted behind the propeller. To access the impeller, pull out the clip used as a protection on the propeller nut, unscrew this latter and pull out the propeller; now open the lid where the impeller is housed.

Always make sure that the propeller has no chippings and that the skeg is fine as well. Sometimes they can be disassembled and replaced; otherwise they can be repaired with a metal filler or with a weld overlay.

Near the skeg is the zinc anode for seawater or a magnesium anode for fresh water. If its wear doesn’t exceed 20% this part can be cleaned in vinegar.

Up the shaft you find the lifting mechanism: it usually only has to be greased and, if needed, cleaned with petrol and greased.

Little touches of paint might be needed on the most easily damaged areas.

Also check and grease the clamps since they can get seized if screwed up or loosened at their end of stroke; when the engine is not in use, you’d better leave them in a half-stroke position.

The throttle is usually very rusty: check and grease the cable from the accelerator to the carburettor. Also check the fulcrum of the throttle lever and screw up the bolt.

As for the engine, here are the steps to be followed:

  1. Clean the carburettor and the air filter
  2. Clean the spark and replace it with a similar one if needed
  3. Clean the tank and filter (integrated in the tank or in the jerrycan)
  4. Replace the start rope.

Cleaning of the carburettor requires that you disassemble this part, open the float chamber, and check the nozzles and the needle holder. These components can be dirty and worn out. Make sure all parts are correctly assembled and screwed up, in particular the petrol tube.

Cleaning of the air filter is simple: it only requires paper and possibly petrol to brush on it as we did for the carburettor. Compressed air is very good for drying and cleaning.

Drain the tank and replace the filter; check the tubes and clamps.

Electronic components such as trim tabs, slides and starters have to be checked: cables can be pinched and rusty. Use spray Vaseline to create a protection coat.

Davide Zerbinati
Latest posts by Davide Zerbinati (see all)