seatrials
Single M18E2 and MFS 20E on 3.7m 2000 Stessl EdgeTacker vee-nose punt, swinging 9.1-
inch and 11.5-inch props and pushing 360kg and 370kg respectively. Average of two-way
runs on Lake Munmorah and Budgewoi Lake, NSW, in calm water. Range is in nautical
miles using 25lt plastic remote fuel tanks with a 10% reserve.
ENGINE M18E2 MFS 20E
TROLLING 700rpm 900rpm
KTS 1.8 2.3
LT/H 0.8 0.4
RANGE 50 129
PLANE RPM 3300 3300
KTS 10 10.8
LT/H 3.4 2.7
RANGE 66 90
CRUISE 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 90Tohatsu M18E2
versus MFS 20E
OLD SCHOOL MEETS NEW GENERATION...
T
he M18E2 has
been one of
Tohatsu’s most
popular models
because it has
way more grunt than a 15
but weighs a lot less than
two-stroke 20s. It was first
released in 1982 as the M18A
with above-prop exhaust,
but through the eighties
and nineties was upgraded
with through-hub exhaust
and redesigned combustion
chambers for better fuel
burn and lower emissions.
Though it still remains a50:1 premix engine (after 10
hours on 25:1). The current
M18E2 runs a lot better than
its predecessors with less
oil smoke on cold start up
and less vibration across the
entire rev range even though
it still has mechanical ignition
timing advance.
Designed more for
commercial operators (it
was a favourite amongst
professional fishermen on
Lake Macquarie) it has an
auxiliary cooling water intake
under the anti-ventilation
plate, rod-operated throttlecontrol and a thermostat
separate from the cylinder
head for easy replacement.
With the M9.8B the cylinder
head must be removed
from the block to access the
thermostat.
Six trim positions and a
single shallow-water drive
setting are provided along
with an automatic reverse
lock and manual tilt lock.
Power head access is excellent
and the bowl-type fuel filter
provides better protection
than the inline unit of the
M9.8B.Released last year, the MFS
20E is Tohatsu’s first battery-
less EFI four-stroke under
25hp. Opting for EFI allowed
Tohatsu to use a smaller
power head and combined
with a new plastic engine
pan and slimmer leg, the 20E
is only five per cent heavier
than the M18E2. It has the
same transom brackets as
its two-stroke counterpart,
but the trim tab anode has
been omitted. The fuel filter
also has a water drain and a
canister oil filter helps keep
the sump oil cleaner between
changes.
Power head access is still
excellent and the four-valve
engine is non-interference.
The camshaft belt is designed
to last 800 to 1000 running
hours. The electronic ignition
timing advance system
incorporates a 6300 rev
limiter.
The 20E starts way more
easily than the M18E2 and
is quieter at or near WOT.
Vibration levels across the
entire rev range are also much
lower. And there’s an upfront
gear shift which makes
operating the 20E easier.
Servicing intervals are
every 50 hours or annually
after the first 20 hours and the
recreational warranty for both
engines is three years.Two- versus Four-Stroketradeboats.com.au 37