Yamaha F60A

Released on the Aussie market in May, the F60A is a bored-out version of the long-running F50A and is in essence a four-cylinder, four-carburettor version of the F40B. Both tiller steer and remote control models are available, both with power trim and tilt but only in standard longshaft form.

At this stage Yamaha has not released a 'B' series version of the F60. The F50 'B' model has a 2.33:1 gear ratio that effectively converts engine torque to thrust and enables the F50B to easily plane workboats such as the Southwind UB580. But with its relatively small gear ratio the F60A is suitable only for aluminium hulls to five metres.

For its output the F60A is a compact motor and has all the features of its F50 counterpart, such as CDI-microcomputer ignition, a cold-start fuel primer and a voltage-regulated 10-amp alternator.

The ignition system electronically advances the ignition timing, during both normal operation and for cold starts, and is connected to a comprehensive engine protection system. Should the engine overheat, overrev or suffer oil pressure loss the revs automatically reduce to around 2000 revs. The primer system eliminates the need for an electrically-operated manual choke system and provides turnkey starting without worrying about over or under choking.

Yamaha has reduced exhaust emissions by separating oil from piston ring blow-by gases and returning fuel vapours to the intake manifold. According to Yamaha, the F60A exceeds US EPA 2006 exhaust emission regulations and meets the tougher California Air Resources Board (CARB) 2004 requirements, but no mention has been made whether the F60A complies with the CARB 2007 or 2008 requirements.

Mounted on a Quintrex 475 Freedom Sport bowrider, the demo F60A started instantly hot and cold with none of the auto-choke problems that afflicted early F50 models. No oil smoke was emitted at any time and across its entire rev range the demo motor appeared slightly smoother-running than the F50. Power astern was good and no cooling water starvation occurred providing the antiventilation plate was kept immersed.

Spinning a 12-inch pitch alloy prop and pushing a total of 800kg (including three adults), the F60A trolled at 4.5kmh consuming 0.9lt/hr. However, the trolling revs of 800 were too fast for serious freshwater anglers and Yamaha should reduce these to 700.

The demo motor achieved a clean plane at 23.5kmh on 3600 revs and at 4000 revs it cruised quietly at 31.0kmh consuming a reasonable 7.8lt/hr. No prop ventilation occurred through tight figures of eight at 4000 revs.

Surprisingly for a carburetted four-stroke, with its induction roar the F60A was quiet enough for us to hold a normal conversation at Wide Open Throttle (WOT), where it averaged 51.0kmh on 5650 revs using 19.5lt/hr.

Compared to a two-stroke Yamaha 70B on this hull, the F60A performed quite well. Pushing a total of 750kg (including two adults) and spinning a 17-inch alloy prop, the 70hp averaged 4.6kmh at Dead Slow Troll (DST) on 700 revs and planed us cleanly at 24.0kmh on 3000 revs. Increasing the revs another 1000 returned an average of 38.0kmh consuming 10.8lt/hr, while the WOT average was 54.9kmh on 5450 revs using 26.0lt/hr.

Undercowl access is excellent and powerhead components such as the spark plugs, dual ignition coils, engine oil filler cap and dipstick and spin-on oil filter are easily reached.

The recommended servicing intervals are every 50 hours or six months for the first two years after the initial 10-hour service, then every 100 hours or once a year, which also applies to waterpump impeller replacement. However, as the F60A operates under entirely different loads to automotive engines and with its saltwater cooling runs a lot colder than these I would change the engine oil and filter every 50 hours or six months, whichever comes first.

Yamaha's F60A provides a useful top-end performance increase over the F50A without incurring much of a weight penalty. Logical thinking went into its design and construction, it's well finished and with regular maintenance it should last just as long as its less-powerful counterpart.

The warranty coverage is two years for recreational applications.