Guides for boat owners
Boat engines: service and faults
Impeller, oil, drive, propeller and winterising. Step by step.
Replacing the impeller – when, how and signs of wear
The impeller cools the engine. How to tell it's worn, how to change it, and what to keep on hand.
Changing the oil in your boat engine – inboard and outboard
How to change the engine oil and oil filter on inboards and four-stroke outboards, and where to dispose of the waste oil.
Changing gearcase oil in outboards and sterndrives – quantity, oil type and steps
Gearcase oil for outboards and sterndrives: the oil type, quantity and filling method depend on the model. See manual examples and how to deal with milky oil.
When should your outboard be serviced? Intervals from five brands
Compare service intervals from Yamaha, Mercury, Suzuki, Honda and Tohatsu. The model and whichever comes first – hours or calendar time – decide.
Drive bellows: when they need replacing and what the job involves
Tell the U-joint bellows from the exhaust bellows, identify the drive and order the right kit. How to plan a bellows replacement without gambling on the seal.
Boat engine temperature alarm: secure the boat and find the cooling fault
What to do immediately if the engine overheats, and how to tell a blocked raw-water flow from a fault in the engine's closed cooling system.
Propeller losing grip: cavitation or ventilation?
The difference between cavitation and ventilation, how to react when the engine over-revs, and what to check before changing the propeller.
E10 or alkylate petrol in your boat engine? Choose by the manual and oil system
E10 approval is model-specific. Distinguish between ethanol content, octane rating and two-stroke oil before choosing pump petrol or alkylate petrol.
Choose a propeller by pitch, diameter and WOT rpm
Read the propeller markings, calculate pitch and slip, and test-run against the engine's specified wide-open-throttle range.
Winterize your boat engine – step by step
How to winterize inboard and outboard engines: antifreeze, oil, fuel, impeller and battery.
Winterising your outboard – step by step
Flush, stabilise the fuel, change the oil and store the engine upright. How to get your outboard through the winter.
Replacing a sacrificial anode – zinc, aluminium or magnesium?
Which anode suits fresh, brackish and salt water, when to replace it and what to keep in mind when fitting it.