Video: Mercury FourStroke outboards

By: Andrew Norton

Presented by
  • Trade-A-Boat

You're going to love the performance and ease of maintenance of the new Mercury FourStroke outboard motor range. Check out these videos we shot on the new engine range.

As I approach my twilight years, I crave a simple lifestyle. And outboard engines that are straightforward to maintain and service.

Although I’ve always preferred DFI two-strokes over four-strokes above 60hp, Mercury’s new F80 to F115 FourStroke outboards are the first four-strokes I’d seriously consider buying in this power range. All are based on a four-cylinder 2065cc engine that has roller cam followers (no valve clearance adjustments) and a single chain-driven overhead camshaft, making them no more complex to service than a DFI two-stroke. All are over square, (the cylinder bore is greater than the stroke for lower piston speeds), unlike the marinised car engines in this power range.

A combination of extremely low copper content alloys also gives a long life in saltwater and by reshaping the gear case torpedo to have a more pronounced profile hydrodynamic, drag is reduced by 15 per cent. All maintenance points such as the sump oil dipstick and canister oil filter are easily reached on the clean powerhead layout.

Because the camshaft lobe profiles have been designed to provide maximum torque well down in the rpm range, all the models use more fuel at Wide Open Throttle than their direct four-stroke competition. But in the 80 to 115hp outboard motor market, good holeshot and midrange fuel efficiency are more important than top-end efficiency. I’m sure most buyers can live with this compromise!

Unlike DFI outboards the new four-strokes are quiet and there’s no oil smell when backing upwind. And they are light too with even the Mercury F115 weighing in at 163kg, less than the direct four-stroke outboard competition which has much smaller displacement powerheads.


Videos: Mercury FourStroke outboard motors

We spent a couple of days reviewing several new engines in the new Mercury FourStroke outboard motor range. We tried several configurations on different models and also compared the new FourStroke outboards to the older Mercury models. Our video crew was kept very during the entire multi-day shoot, as was engine expert Andrew "Engine Man" Norton and our senior boat tester, John "Bear" Willis. Here's what they had to say.


Mercury 80hp Four Stroke outboard motor

Mercury F80 FourStroke outboard

Don’t stress over this outboard wearing out. The Mercury F80 develops maximum power at just 5000rpm, way lower than competing engines.

Mercury Four Stroke 90hp

Mercury F90 FourStroke outboard

Loads of low-down grunt and efficient running made the F90 FourStroke Andrew "Engine Man" Norton’s pick of the lot.

Mercury 115hp Four Stroke engine

Mercury F115 FourStroke outboard

The F115 is quieter than its predecessors due to decreased load on the engine. It also planed faster when fitted with a new Command Thrust gearcase. 

Mercury Command Thrust Gearcase

Mercury Command Thrust gearcases

The new FourStroke range isn’t just about engines. Mercury also redesigned its engine gearboxes to reduce drag and increase overall performance.

Anthony Brown Mercury Marine

What else is new?

Mercury Australia’s Anthony Brown explains what else is new, from significant engine weight savings to the SmartStart system that won’t wreck the starter motor.

See the full version of this story in Trade-A-Boat #455, July / August 2014. Why not subscribe today?



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