REVIEW: TOHATSU MFS 20E SPORT

By: ANDREW NORTON, Photography by: TRADE-A-BOAT

Presented by
  • Trade-A-Boat

Tohatsu’s new 20E Sport was designed to compete directly with two-strokes...

Tohatsu -MFS-20E-Sport -3

The biggest problem with four-strokes so far has been their weight compared to two-strokes. Fine if the hull is designed to take the weight but not so good when re-powering older hulls that were never designed for the higher transom weight. Not to mention the extra stresses on older trailers aft of the axle(s).

Tohatsu has been working steadily to reduce the weight of its midrange four-strokes so they compare directly with two-strokes. The MFS 40A and 50A released a few years ago are prime examples and the new 20E Sport is the next stage of development. Currently it’s the lightest four-stroke 20 on the Aussie market.

By reducing the piston displacement, leg dimensions and opting for a plastic engine pan the 20E is a full 8.5kg or 17 per cent lighter than its 20D predecessor, yet through using EFI actually produces more torque. The 20E is only 2kg or five per cent heavier than its long running two-stroke M18E2 counterpart so can safely be mounted on older tinnies such as the 3.8m Savage Snipe dinghy.

THE NITTY GRITTY

Tohatsu -MFS-20E-Sport -1

The carbie 20D displaced 351cc with a cylinder bore of 61mm and piston stroke of 60 whereas the 20E has the same bore but a shorter stroke, resulting in a five per cent smaller piston displacement. Apart from this the new power head still has decompression starting and two valves per cylinder actuated by a single belt-driven overhead camshaft. Fortunately the engine is non-interference so that if the belt breaks the pistons won’t contact the valves. It develops a whopping 26Nm of torque at 4500rpm compared to 25.5 at the same revs for the carbie 20D.

Unlike the M18E the ignition has electronic timing advance and the ECU (Electronic Control Unit) automatically reduces revs to 2800 should the engine overheat or suffer low oil pressure. The rev limiter is set at 6300rpm which we experienced during initial trials before swapping to a larger pitch prop.

Servicing intervals are every 100 hours or six months after the initial 20-hour service. A large capacity canister oil filter is fitted with a clever drain hose ensuring any oil that escapes the filter during removal is captured when the engine is fully tilted. A range of oils may be used but the recommended oil is Quicksilver FCW SAE 10W30, which can handle ambient temperatures to over 40 degrees. With oil filter change the sump capacity is a reasonable 1.2lt so any dilution during extended trolling periods shouldn’t be an issue.

The plastic engine pan can be split for full power head access though removing the rocker cover to check valve clearances is straightforward. Steering friction is easily adjusted using a horizontal lever just below the upfront gear shift. Oddly enough there’s no trim tab beneath the anti-ventilation plate to counteract steering torque but in testing there didn’t seem to be a need for one.

Six trim positions are fitted plus a single shallow water drive setting. A fold-up carry handle is fitted within the transom brackets and is made of strong plastic to further reduce engine weight.

ON THE WATER

Tohatsu -MFS-20E-Sport -2

Lakeside Marine, the national Tohatsu distributor, set up a run-in 20E on a 3.7m Stessl Edge Tracker V-nose punt, the same hull I tested an M18E2 on in 2000. Lakeside is targeting the 20E at boaters who want the performance of the 18 but smoother running and fuel efficiency of a four-stroke.

Initially the demo 20E was set up with the standard short shaft 10in pitch prop but the additional power and torque of the engine on this hull showed that the maximum pitch of 11.5in would be needed. Running on premium unleaded (95 RON) the engine was easily started from cold with a firm two-hand pull but when hot only one hand was needed. For a relatively big displacement twin vibration levels were low. Providing the anti-ventilation was kept immersed when using shallow water drive power astern was good and no cooling water starvation occurred.

Once warmed up and set on the third trim position the demo 20E accelerated out of the hole as hard as the M18E2 but was way quieter at or near WOT.

THE WRAP

According to OEDA currently 69 per cent of all outboards sold in Australia are low emission, whether that be four-stroke or DFI two-stroke. Clearly buyers want low emission technology and having an engine that’s little heavier than a comparable output two-stroke helps sway their decision. In any case carbie two-strokes won’t be able to be sold in Oz from 2019 onwards. Fortunately for the Kiwis there are currently no such restrictions, but in the nanny state (aka Australia) we won’t be given that choice!

The Japanese-made 20E is beautifully engineered and finished and with regular servicing should provide years of angling pleasure. For more on the 20E call Lakeside on (02) 4392 6110 or visit www.tohatsu.com.au

TOHATSU MFS 20E SPORT SPECS

TYPE Twin-cylinder SOHC EFI four-stroke outboard

RATED BHP/MHP* 19.7/20.0 at 5750rpm

REC. WOT RANGE 5400 to 6100

DISPLACEMENT 333cc

BORE X STROKE 61 x 57mm

GEAR RATIO 2.15:1

WEIGHT 43kg (short shaft) 44kg (long shaft)

RRP $3667 (short shaft) $3720 (long shaft)

OEDA stars 3 (plus Euro Recreational Craft Directive 11)

*Brake horsepower/metric horsepower

SEA TRIALS

Single M18E2 and MFS 20E Sport on 3.7m Stessl Edge Tracker V-nose tinny. Total displacement including two adults and test equipment 360kg and 370kg respectively. Average of two way runs on Lake Munmorah and Lake Budgewoi, NSW. Range is in nautical miles with a 25lt remote fuel tank and 10% reserve.

ENGINE

M18E2

MFS 20E SPORT

Gear Ratio

1.85:1

2.15:1

Prop Pitch

9.1 inches

11.5 inches

Trolling (RPM)

700

900

KTS

1.8

2.3

LT/H

0.8

0.4

Range

50

129

Half Throttle/Plannning (RPM)

3300

3300

KTS

10.0

10.8

LT/H

3.4

2.7

Range

66

90

Two-Thirds/Three Quarters (RPM)

4000

4900

KTS

12.9

18.1

LT/H

3.9

3.7

Range

74

110

WOT (RPM)

5900

5900

KTS

22.8

23.2

LT/H

8.4

5.8

Range

61

90

Check out the full review in issue #499 of Trade-a-Boat magazine. Subscribe today for all the latest boat news, reviews and travel inspiration.

 


Want the latest stories delivered straight to your inbox? Sign up for the free TradeBoats e-newsletter.