How to service a Tohatsu outboard
Servicing your Tohatsu outboard regularly keeps it reliable, fuel-efficient and protected from corrosion, especially in saltwater. A simple annual service (or every 100 hours, whichever comes first) covers most essentials.
1) Safety first
Turn the engine off, remove the safety lanyard, and work in a well-ventilated area. If you have one, use a proper outboard stand.
2) Flush and rinse
After use, flush the cooling system with fresh water (muffs or flush port). Rinse the exterior and let it dry to reduce salt build-up.
3) Change engine oil (4-stroke) and filter
Warm the engine briefly, then drain the oil, replace the oil filter, and refill with the correct marine-grade oil. Check for leaks.
4) Replace gear oil
Drain the lower unit oil, inspect for milky colour (water ingress), and refill from the bottom port until it vents cleanly. Fit new sealing washers.
5) Inspect the water pump impeller
Overheating often starts here. If you have weak tell-tale flow, replace the impeller and check the water pump housing and gaskets.
6) Check spark plugs, fuel system and corrosion protection
Fit fresh spark plugs if worn, inspect/replace the fuel filter, and check hoses for cracking. Clean and replace sacrificial anodes as needed, then grease fittings and the prop shaft before refitting the prop.
Finish with a quick test run, confirm a strong tell-tale, and record the date and hours for your next service.
