by Dom Wiseman

Outboard engines come in a wide variety of shapes and sizes and Yamaha has a comprehensive line-up of four-stroke power from 2.5hp, all the way up to the enormously powerful 350hp. While there is a wide range of units available, many of us cut our teeth at the lower end of the spectrum, first with 4 and 6 horsepower units on small tinnies before heading up to the more powerful 25 and 30 horsepower range on slightly bigger units. This makes the new Yamaha F25 perhaps one of the most keenly anticipated engines in quite a while. It is still a popular segment of the market.

There several formats you can order the F25 in

  • manual start with tiller steer and manual tilt
  • manual start with tiller steer and electric trim and tilt
  • electric start with forward control
  • electric start with forward control and power trim and tilt

Yamaha also sell kits for owners wanting a tiller steer configuration with electric start.

The F25 will also be available in 20 and 25-inch transom lengths.


The new Yamaha F25 replaces the F25G. The new platform is considerably lighter and smaller than its predecessor. With a total weight of 57kg the short shaft variant is an impressive 25% lighter than the model it replaces. The footprint is also smaller with a more compact engine design able to accommodate a smaller cowling and shaft.

Yamaha F25 1

Yamaha F25 2The weight and size reduction has been achieved by compacting the engine configuration. The F25 inline two-cylinder, four valve engine uses a single overhead camshaft. In the previous model, the balancing weight was the equivalent of adding a third cylinder, however, on the F25, Yamaha has moved the balancer, which has also been redesigned, in between the two cylinders creating a more compact set up. They also have redesigned the mounting bracket to saving additional weight. The new bracket allows a 45 degree angle of use either side which is more than enough for any operation.

Internally, they have made some other technological advances such as adding batteryless electronic fuel injection which is a new feature across the four-stroke range. The fuel injection is managed by the engines ECU. This delivers efficient operation without the need for a battery to prime a pump to deliver the fuel. The intake and engine manifold and throttle body are made of durable plastic which also helps to reduce noise.

Remarkably, and importantly, Yamaha has managed to extract a decent load from the alternator. At wide open throttle delivery is an impressive 16 amps but at only 1000rpm it is still a mind blowing 12 amps. This makes it well suited to the demands of modern anglers running multiple electronic units.

The Yamaha F25 also has been designed with the consideration that an owner may wish to store the unit, so carry handles have been placed in all the convenient points. It also comes with an attachment so a hose can be attached to flush the engine with fresh water.

Yamaha F25 3

The unit can also be fitted with Yamaha’s ‘Y-Cop’ wireless immobiliser. This handy feature pairs the engine with a waterproof fob that allows you to lock or immobilise the engine. It stops the engine from starting without pressing the button on the fob, providing some peace of mind when you leave the boat on the beach or at a wharf while you’re ashore.

It is important to note that the test boats were also fitted with a fuel separators/filters. Yamaha recommends this as a standard set up with any four-stroke engine.


The Yamaha F25 is very easy to use in any of its configurations. The tiller handle is ergonomic with easy access to the gear lever. The throttle is also easy to manage and has a durable grip for comfort. As with any tiller steer, long drives will become taxing purely from the nature of the grip angle. If you’ve never had the opportunity to own a tiller steer with electric trim and tilt, it is an option I would go with personally. It makes the whole process very simple and when coming in to fish flats and shallow areas, comes into its own and negates the need to stop and manually tilt the engine up so as not to hit the bottom. That said the manual tilt has four tilt angles and two shallow water drive options.

The manual start version is very easy to get going courtesy of a reduced compression starting mechanism which means you aren’t going to throw your arm out trying to start the engine. A simple firm pull on the cord will have the engine turning over immediately.

The forward control version is much the same and again I would opt for the electric trim and tilt if I was buying one for myself. Being slightly further away from the engine means that noise isn’t an issue, although that being said the engine is hardly loud.

Yamaha F25 9

The acceleration from this unit is quite impressive. It’s quiet and powerful and had the 3.98m Sea Jay  rises onto the plane easily. The torque and overall speed is impressive. There is a notable improvement on the old engine. With a tiller steer unit fitted to the Sea Jay we saw a top speed of 42.60km/h (23 knots) with a fuel burn of 9.10 litres per hour meaning travelling flat out you would get a range of just over 40kms from the standard 20-litre tank, which is  pretty impressive.

On the back of a forward control, side console Horizon 390 Stalker we saw a wide open throttle speed of 40.15km/h with the same fuel burn.  If you have a forward control option it may be worth considering the optional command link gauges that will provide engine data such as fuel burn, speed and revs in either liquid crystal or full colour displays.

The Yamaha F25 is also fully compatible with NMEA 2000 which means it will share information with third party multi function displays.


This engine is a beauty and will certainly find its way onto many inshore boats around the country. The Yamaha products never seem to disappoint and with the move towards fuel efficient power, the new F25 places itself well against the competitors with reduced weight, footprint and efficient fuel usage.


  • Easy to manage and store
  • Efficient


  • Still a handful at 57kgs


Price: (from) $4,829
Engine Type: 25hp Four-stroke SOHC L2 4 valves
Displacement: 432 cubic cm
Bore and Stroke: 65.0 mm x 65.1 mm
Alternator: 16A
Weight: (from) 57kg
Fuel: 91 RON Regular unleaded, portable tank
Emission rating: 3 star