There's no doubt that Tohatsu Corporation manufactures well-engineered low pollution motors. Its two-stroke Direct Fuel Injection TLDI models from 50-90hp return low-speed fuel efficiency unmatched by comparable four-stroke outboards, while its four-stroke range from 4-30hp includes motors that are unique in their respective power ranges.

So when the Australian distributor of Tohatsu outboards, Lakeside Marine, provided me with an opportunity to test its recently-released MFS 25A, I jumped at the chance!

This model is available in manual start, electric start and electric start with power trim and tilt. The lower unit is straight from the two-stroke 25/30hp model, but the powerhead is a three-cylinder, three-carburettor version of the twin cylinder, single carbie MFS 15/18B we reviewed in Trailer Boat late last year.

The MFS 25A has the upfront gearshift and all the engine protection features of its smaller counterparts, which include a rev limiter (6500), automatic reduction of revs to 2800 should the oil pressure drop and an overheat warning buzzer.

The main benefit for Tohatsu in opting for a three-cylinder powerhead in this power range is that it can provide both 25 and 30hp from one base engine, instead of having to develop an individual 25hp model as did Mercury Marine and Yamaha.

The three cylinders give much better running balance than the twin cylinders and balancing piston of the Mariner/Mercury and Yamaha motors without significantly increasing the motor's weight.

The three cylinders also make the MFS 25A so easy to start manually that unless you want the luxury of electric starting it really isn't necessary.

In February, Dave Denny, from Lakeside, and I spent a day evaluating an MFS 25A, just as we had done with the TLDI models and smaller four-strokes many times before. In Tune Marine of Long Jetty, NSW, provided a Stacer 420 Seahorse fitted up with extruded sidedecks, forward casting platform and an aft platform with splashwell. Including two fuel tanks, test equipment and ourselves, the total displacement was about 500kg, more than enough for any 25hp motor!

Hot or cold the demo motor started easily with a firm two-handed pull. The automatic choke kept engine revs up for a few minutes until normal operating temperature had been reached. Using Valvoline VSL 1540 Super Premium SAE15W40 oil, no oil smoke appeared at any time. Providing the antiventilation plate was kept immersed, power astern was good and no cooling water starvation occurred, while at all speeds the pilot water discharge was clearly visible. Vibration levels at the minimum trolling revs of 900 were slightly higher than Honda's BF25 but significantly less than the Mariner/Mercury and Yamaha competition.

Noise levels were comparable to these big-displacement twins and higher than the Honda.

Spinning a 10in pitch Tohatsu alloy prop, the demo motor trolled at 4.1kmh using 0.5lt/hr and on the third trim hole achieved a clean plane at only 15.6kmh on 3500rpm. Set on the fourth trim hole for best all-round performance, the MFS 25A cruised quietly at 23.4kmh on 4000rpm, consuming 4.6lt/hr. Through tight figures of eight there was only a slight amount of prop ventilation.

Across a 10cm windblown chop, the Tohatsu averaged 37.7kmh at Wide Open Throttle (WOT) on 5600rpm, using 9.4lt/hr, with similar noise and vibration levels to the BF25 but less than the twin cylinder competition. Trimmed out on the fifth hole, the WOT average was 38.4kmh on 5650rpm, but the fuel consumption was 9.9lt/hr. Through anything but wide turns the prop ventilated excessively.

Powerhead access under the strongly-moulded upper cowl is very good, with components such as the oil dipstick and spin-on oil filter easily reached, but only an in-line fuel filter is fitted instead of the bowl-type unit of the two-stroke 25. The large capacity (for a 25) sump should help absorb any oil ‘sludging' between changes. Recommended servicing intervals are every 50 hours or six months after the initial ten hour/one month service, and the waterpump impeller should be replaced every 100 hours or yearly.

The warranty provides two years of coverage for recreational applications.