Yamaha 2-Stroke Oil Maintenance for 100-Hour Service

Timely maintenance is the key to outboard engine longevity. If you own a Yamaha 2-stroke with an oil-injection system, performing oil system service during your 100-hour interval is essential. This quick guide walks you through the process so you can maintain your Yamaha’s performance and avoid costly issues down the line.

Step 1: Locate and Access the Remote Oil Tank

Most oil-injected Yamaha 2-stroke outboards feature a remote oil tank located inside the boat. Access may require removing an access panel, cooler, or livewell tub. Once visible, loosen the tank from its bracket to gain full access.

Step 2: Inspect and Replace the Inline Oil Filter

Follow the oil supply hose coming from the tank to find a small white inline filter that strains oil en route to the engine. This component is often overlooked but is critical. A clogged or failing filter can cause your engine to enter safe/reduction mode—or worse, result in oil starvation.

Use scissors or snips to carefully remove the zip ties, quickly swap the old filter for a new one, and re-secure the hose. Prepare for minor spills with petroleum sorbent pads and wear nitrile gloves to protect your hands.

Step 3: Check the Tank for Debris or Water

With the tank removed from its bracket, shine a small flashlight into the corners of the translucent tank. Look for water or debris, which could be introduced by leaving the fill cap open, using dirty funnels, or damaged o-rings.

If contamination is present, remove the tank completely, drain it, and clean it thoroughly before reinstalling it into the bracket.

Step 4: Prime the Oil System

Remove the engine cowling and use the manual oil transfer switch on the engine to verify oil flow through the new inline filter. This ensures the system is primed and ready. Once confirmed, reinstall all components and your Yamaha 2-stroke oil maintenance is complete.

Pro Tip: Use Only Yamalube 2-Stroke Oil

Always use Yamalube 2M or equivalent marine-grade 2-stroke oil for Yamaha outboards. It’s engineered specifically for outboard use, offering superior lubrication and carbon deposit control.