Yamaha Lower unit oil is a special type of oil made for the best performance of the Yamaha outboard engine. Unlike ordinary automotive engine oils, lower unit oil is much different as it has much tough job to do. It is used to lubricate the internal moving components of engine and reduce friction between them to have a smooth working of the outboard engine. As the outboard engines works with much heavy load so for this reason lower unit oil is made of many different types of compounds and is enhanced by adding different additives to ensure the best performance of an outboard engine. Lower unit oil is needed to change once in a season or after every 100 hours to ensure best performance.

Why lower unit oil is needed

As lower unit the working and most important part of outboard engine thus its maintenance is necessary to have a hassle free journey on water. Lower unit oil is needed to lubricate it and lubricating your lower unit is very important as it gives the thrust to move your boat, and without this your outboard engine will be ruined. So for keeping your lower unit in best performing condition and to enhance its useful life you should use Yamaha lower unit oil. The lower unit oil reduce friction between the moving parts of lower unit and also prevent the wear and tear of it and helps in best performance. It also act as cleanser of internal parts by removing the sludge which is accumulated due to the working of lower unit at high pressure. Following are the reasons for which lower unit oil is needed:

Load on engine:

As the lower unit have to deal with much greater drag force of water so it have to work in heavy load, so for its best performance in heavy load lower unit oil is needed for its best functioning.

Speed of engine:

The working speed of and outboard engine is much greater due to the resistance of water. So you should use Yamaha lower unit oil, instead of an ordinary automotive oil, which is specially made to help lower unit work efficiently.

Working environment:

As the lower unit is always in the water and in salt water things get more dangerous as it can corrode the interior of the outboard engine. So the Yamaha lower unit oil helps to prevent from such damage.

Internal temperature:

In salt water the salt begin to crystallize if temperature rises above certain limits, and blocks the cooling passage of the outboard engine which can cause serious damage to the engine due to overheating. So Yamaha lower unit oil is made to keep the temperature low thus preventing such damage.

How to choose right oil for lower unit

As lower unit oils are much different from other automotive engine oils, so there are different types of these oil which includes FC-W for four Stroke engines and TC-W3 for two stroke engines. These are the requirements from National Marine Manufacturer’s Association for lower unit oil and Yamaha lower unit oil meets these requirements. Following are different types of lower unit oils:
5W-30 Full-Synthetic—this is the best oil for high performing outboards.
10W-30 Mineral Base (conventional)—this is a universal oil ideal for almost all types of environments.
20W-40 Mineral Base (conventional)—for the larger outboards and warm climate this is best.
However whatever oil you choose, ensure that it is of the right type and required viscosity and best suits your needs.

Yamaha Lower Unit Oil Weight

You can use a 80/90 weight, semi synthetic blend. You should be able find from nearest marine store. You might want to use quick silver brand at Walmart. You may need a little over a quart. If you want to get one from our website, we’ll suggest SEI marine grade lubricant.

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