Anti-Aging Secrets Revealed
Regular Lubrication Service Key to Marine Engine’s Longevity

You have a lot of money tied up in your outboard and it only makes sense to do everything you can to help the engine last as long possible, doesn’t it? The “anti-aging secret” isn’t difficult, nor is it particularly expensive, and if you’re somewhat mechanically inclined, you can work this magic without putting the boat in the shop.

The secret is to be fanatical about performing regular lubrication service on your outboard as outlined in the engine owner’s manual. Simple stuff, actually – the only magic involved is sticking to the outboard’s maintenance schedule.

Lubrication Basics
Four-Strokes

A four-stroke outboard engine needs periodic oil changes because over time, the oil gets dirty from combustion by-products and metallic shavings resulting from the engine’s internal components rubbing together. In addition, heat and condensation can cause the oil to deteriorate, losing some of its lubricating properties in the process.

Changing the engine oil is pretty straightforward – run the engine until it reaches operating temperature, turn off the engine and trim the outboard to a vertical position. Drain the warm oil into a drain pan, remove and replace the oil filter, fill the engine with new oil, start the engine (don’t rev, verify oil pressure via gauge at helm), check for leaks, and clean up any mess.

Two-stroke outboards don’t need oil changes like their four-cycle cousins, but still require lubrication attention to keep operating at their maximum potential.

All Outboards
Both four and two-stroke outboards have grease fittings in a variety of places, including on the clamp bracket. Again check the owner’s manual for specific locations so you don’t miss any fittings.

In addition, four-stroke and two-stroke propeller-driven outboards have a gearcase (also called lower unit) filled with thick oil that must be changed at the intervals given in the owner’s manual. Changing the gearcase lube isn’t technically hard – tilt the engine up a bit and place a drain pan under the front of the gearcase. Remove the drain screw (usually located near the forward underside of the gearcase) and the vent screw (close to the top of the gearcase); the gear lube should flow into the drain pan.

Let the gearcase drain for a while, then trim the outboard to a vertical position. Using a small hand pump and the recommended gear lube, fill the gearcase via the drain screw hole until the lube just starts to dribble out of the vent screw hole. Replace the vent and drain screws (make sure to use new gaskets on the screws), clean up any stray lube.

Before discarding the old gearcase oil, check it for water contamination. If the old lube seems to be milky-whitish in color, the gearcase may have a leak. If this happens, it’s best to put the engine in the shop to have the gearcase checked out by a certified technician.

The time you spend waiting for the gearcase lube to drain is  a good time to take off the propeller and lubricate the propeller shaft. After removing the propeller, clean the propeller shaft, and check for fishing line that may have become wrapped around the shaft while boating. (If you find fishing line, cut it off and inspect the propeller shaft seal for damage caused by the line).

Generously lubricate the propeller shaft with waterproof marine grease and reinstall the propeller.

Outboard Lubrication
Service Checklist

• Change the engine oil and replace the oil filter (four-stroke engines)
• Use the best oil and filter you can buy, preferably the engine’s manufacturer’s brand
• Replace fuel filters (on engine and boat)
• Fuel filters on the engine may be challenging to find, refer to the owner’s manual for locations
• Lubricate throttle/shift linkages
• Lube cowl latches
• Visually inspect wires, belts, and hoses for anything that looks amiss or out of place
• Lubricate grease fittings (there may be several, refer to the owner’s manual for locations)
• Change gearcase oil
• Grease propeller shaft
• Check power trim fluid (where applicable)
• Check hydraulic steering fluid (where applicable)
• Lubricate tiller mechanism (where applicable)
• Dispose of used oil properly in accordance with local and federal regulations

The bottom line is that with regular maintenance, (including lubrication and common sense operation), your outboard should give you many years of dedicated service.

For specific lubricant and service information, refer to your engine owner’s mayamahaoutboards.com. Visit an authorized Yamaha dealer to find out more about your Yamaha outboard. Y