Yamaha 2-Stroke Outboard Spring Maintenance Checklist

For many, spring means boating season has officially arrived. Before you head for the boat ramp and back on the water, you’ll need to run through a bit of spring maintenance on your Yamaha 2-stroke outboard. 

Yamaha 2-stroke outboard spring maintenance

Making sure your outboard is in top condition now means you’re more likely to enjoy a trouble-free boating season ahead. If you winterized your motor before storing it, much of the work is already done. But there are still some checks to go through if you want your Yamaha 2-stroke outboard to be at its peak once it's back up and running. Before you do anything, inspect your outboard for any signs of leaks — lube from the lower unit, fuel, or hydraulic fluid if you have hydraulic trim or steering components — and find and fix them. 

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Yamaha 2-Stroke External Outboard Spring Maintenance

1. Inspect the outside of the outboard for scratches or scrapes, particularly on the lower unit, which is prone to damage from underwater strikes. If you find damage, remove any corrosion from the area, and prime and repaint it as needed.

Yamaha 2-stroke outboard motor spring maintenance

2. Wash and wax the top cowling and the lower unit. A couple of coats of marine wax protect the paintwork and fiberglass from UV damage, and of course makes your outboard look great.

Yamaha 2-Stroke Powerhead Spring Maintenance

Remove the top cowling and give the powerhead a thorough inspection. It’s not unusual for wildlife such as rodents, birds and bugs to nest inside the engine cowling, so remove any unwanted guests.

Yamaha 2-stroke outboard engine spring maintenance

You should’ve replaced the engine oil as part of the winterization process, but check the oil level anyway. A rise in the oil level can mean water in the tank, and it’ll need draining and refilling. If you didn’t change the oil, do it now and make sure you replace the oil filter while you’re at it.

3. Remove and inspect the spark plugs, clean them and check the gaps between the electrodes. If you used fogging oil in your motor when you winterized it, wait to change the spark plugs until after you’ve run the outboard and burned off any remaining fogging oil from inside the motor.

Yamaha 2-stroke outboard spring maintenance spark plugs

4. Inspect the wiring for chewing, burns and corroded connectors. Check that all the connectors are secure, and replace any loose, corroded or damaged wires.

5. Check the hoses for cracking or bulging. Inspect hose ends for leaks, and make sure the clamps and connections are tight. Replace any worn, corroded or loose hoses and clamps.

6. Consult your Yamaha 2-stroke outboard’s user manual to see whether your model has a fuel/water separator filter or other fuel filters. The manual tells you when to replace them, but if you can’t remember the last time you changed a fuel filter, do it now.

Yamaha 2-Stroke Lower Unit External Spring Maintenance

7. The prop exhaust is another favorite spot for nesting wildlife, so remove any creatures, debris or marine growth buildup you find in it.

Yamaha 2-stroke outboard spring maintenance prop inspection

8. Inspect the water intakes, and clear out any debris or marine growth buildup.

Yamaha 2-stroke outboard spring maintenance water intake

9. Inspect all the zincs/anodes and replace any that have corroded beyond 50% of their original size.

Yamaha 2-stroke outboard spring maintenance anode

10. Check the propeller for bent, distorted or cracked blades, as well as for pitting and corrosion. Replace the propeller if it’s pitted or damaged. Make sure the prop nut is tight and the nut’s cotter pin is in place.

Yamaha 2-stroke outboard spring maintenance propeller

11. If you didn’t change the lower unit (gearcase) oil as part of winterization, do it now. Even if you did change it, note that after months of storage, the oil may have settled and need to be topped off. 

Yamaha outboard spring maintenance gearcase lube

Yamaha 2-Stroke Lower Unit Internal Spring Maintenance

12. Your outboard’s impeller should last 2-3 years (see the owner’s manual), but replace it now if you can’t remember the last time you changed it.

Yamaha 2-stroke outboard spring maintenance impeller

13. When installing a new impeller, inspect the water pump housing and replace any worn seals or other parts.

14. If your Yamaha 2-stroke outboard has internal zincs/anodes, the owner’s manual tells you how often to replace them, but do it anyway if they’re corroded beyond 50% of their original size.

Yamaha 2-Stroke Electrical Power and Fuel System Spring Maintenance

15. Inspect batteries for leaks or deformities such as swollen sides and replace them if needed.

Yamaha 2-stroke outboard spring maintenance battery

16. Clean the battery’s terminals and reconnect the wires. Make sure the connections are tight, and coat them with dielectric grease. 

Yamaha 2-stroke outboard spring maintenance battery cleaning

17. Make sure the battery tray or tie-down straps are tightened securely. Charge the battery and test it to see that it’s holding the charge. 

18. If your outboard has an external fuel tank, inspect the outside of it for cracks, damage and leaks and replace it if necessary.

19. Test the fuel by disconnecting the feed line from the motor and using the primer bulb to collect a fuel sample. Check the sample for water or other contaminants, and replace the fuel if necessary.

20. Inspect the fuel bulb and feed line for leaks, cracks or wear and replace them if necessary.

Yamaha 2-stroke outboard spring maintenance fuel line inspection

21. Inspect all the fuel lines running between the tank and the outboard for cracks, bulges or kinks. Make sure all the fuel line connections and clamps are tight and leak-free. Replace any damaged or leaking lines and loose clamps.

Yamaha 2-Stroke Spring Engine Flushing and Running

Use an engine flusher to flush your outboard even if you already did when you winterized it, since it’s been in storage for months. 

Yamaha 2-stroke outboard spring maintenance engine flush

22. Check that you’re getting a good flow out from the tell-tale.

Yamaha 2-stroke outboard spring maintenance tell-tale

23. Check that all gauges and instruments are functioning, and that you have a good voltage reading.

24. Turn off the motor and allow it to cool, then re-check the gearcase lube level and top it off if necessary. 



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