Sterndrive Engine Parts

Motor Parts
Boating Know How
How to maintain the health of my sterndrive

Maintaining the Health of My Sterndrive – 10 Critical Areas

The Sterndrive is among the most popular types of outdrives. Popular brands include the Mercruiser, OMC, and Yamaha mainly found in the US while in Europe the Volvo Penta is most common. These drives are known to be quite ... read more powerful and effective. However, repairing a damaged unit or buying a Sterndrive can be costly.

As a boat owner, you need to pay close attention to the following areas:

1. Fouling

Fouling is always one of the biggest headaches to boat owners. Regular contact with water, especially ocean  water, will lead to marine growth such as barnacles. Getting rid of barnacles usually requires sanding down the area. The application of anti-fouling paint should be done while the engine is still new thus impeding the growth.

2. Electrolysis

Sterndrives are made from metals such as aluminum, steel, iron and zinc. Zinc being anodic (low electrical potential) and aluminum being cathodic (high electrical potential) allows electric ions to flow from the zinc to aluminum. Overtime, the zinc coating will get eroded thus weakening the part. It is, therefore, necessary to maintain the zinc plates and ensure they are cleaned regularly.

3. Corrosion

In certain instances, a whitish powder will coat some parts of the engine. This occurs when electroplating is taking place due to current flow between the metals e.g. from zinc to aluminum. This will only be noticed in dry and not wet conditions. If not corrected in time, the drive will be damaged beyond repair.

4. Lubrication

Like any other outdrive, a Sterndrive will work optimally when there is minimal friction. This is achieved by ensuring the moving parts are moving freely. Visible parts should be cleaned, properly dried and some marine-grade lube or grease applied. The gear oil or lube should also be replaced within the recommended period.


5. Adding Protection

The drives usually come with minimal or no protection. This makes them prone to electrolysis, corrosion, as well as chipping away. There are special compounds that should be used to protect the drive better. These include a pre-primer that removes any corrosion on aluminum. Anti-rust paints are also available for steel.

6. Replacement Parts

Many boat owners will carry out the necessary repairs and service on their Sterndrive. Unfortunately, most will complain of poor performance due to the lack of durability. Usually, the main reason is due to using low a quality Sterndrive engine parts. You should never sacrifice quality for economy as this is always costly in the long run.

7. Drive Shafts

It is important to make sure the drive shaft is moving freely. A bent shaft, a corroded one or a broken seal may make the shafts rotate poorly. This not only consumes power but also harms the engine. Visually inspecting the shafts and seals ought to be done frequently.

8. Chipped Paint

Paint on the drive will wear out or chip over time. This may be caused by poor handling, reckless operation or extended use. Once the bare metal becomes exposed it is necessary to correct it immediately. Proper sanding, applying a primer that resists rust, using quality paint, and following the right procedure are needed.

9. Hoses

The drives feature two bellow hoses; one is for the shift controls and the other for the drive shafts. The water seal between the lower unit and the boat wear out due to use. This may allow water to get in. Things to look into include cracks, rigidness or signs of moisture.

10. Paint Maintenance

Usually, people raise their drives when not in use. Unfortunately, marine paints react with oxygen in the atmosphere. This will affect the anti-fouling properties which ensure corrosion or rust doesn’t take place. Therefore, it is essential to keep the drive submerged in water at all times. Nonetheless, taking it out of water for a day or two won’t cause any harm.

Anyone who’s ever had to repair or replace a damaged Sterndrive understands the high cost of doing so. A single propeller drive will set you back by at least $2500 while a twin-engine will cost no less than $5,000. In fact, buying a new drive unit may cost more than half the price of what the boat is worth. Regularly servicing the engine using proper Sterndrive engine parts will go a long way in avoiding the costly scenarios.
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