torquing
talk
WITH ANDREW NORTONFamily Favourite
THE EVINRUDE E-TEC 75 IS MADE FOR FAMILY RUNABOUTS
O
ne of Bombardier
Recreational
Products’
earlier models,
the 75 is de-
rated from its E-TEC 90
counterpart and has tonnes
of midrange torque. Yet it
weighs substantially less
than the direct four-stroke
competition.
With all the current
emphasis on four-stroke
outboards from other
manufacturers, it’s easy
to forget about Direct Fuel
Injection two-strokes, which
combine traditional carbie
two-stroke performance with
four-stroke fuel eciency.
And even less fuel when
trolling due to the use of
“stratified” combustion.THE NITTY GRITTY
The three-cylinder 75
utilises the same pistons and
conrods as its twin cylinder
40 to 60 counterparts and
the V4 115/130 models. BRP
has applied the traditional
two-stroke design of big
cylinder bore, and short
piston stroke for lower piston
speeds, at or near Wide
Open Throttle, increasing
piston ring and cylinder liner
lifespan.
The E-TEC system of
stratified combustion, injects
fuel in narrow conical spraypatterns near the spark
plugs. The normal air/fuel
ratio of 14.7:1 is used in the
spray area but the overall air/
fuel ratio in the combustion
chamber may be as lean as
70:1. This results in lower
trolling fuel consumption
than most of the direct four-
stroke competition.
At around 1500rpm the
system switches over to
homogeneous combustion
where the overall
combustion chamber air/fuel
ratio is 14.7:1. The lean burn
of stratified mode doesn’t
enable an engine to develop
enough torque to plane a
hull or provide the upper end
performance demanded by
boaters. However, because
the Californian Air Resources
Board (CARB) requirements
adopted by OEDA, in Oz, take
into account that 40 per cent
of usage cycle is at trolling
rpm, E-TEC engines easily
gain a “3 star” rating.
The under flywheel
alternator produces up to
81 amps with 25 dedicated
to battery charging, while
the self contained DFI
means that only a standard
automotive starter battery
is needed and if the battery
is flat, the engine can be
started by hand (though a
1.3 litre triple would sure
give it a workout). Of theDFI 75s, only the E-TEC 75
has this feature. A 60 amp/
hour starter battery weighs
around 15 kg, whereas a 100
amp/hour deep cycle unit
needed for the direct DFI two-
stroke competition, weighs
upwards of 80 kg. Although
this weight is ahead of the
transom, it does tend to
negate any weight savings
from opting for a DFI two-
stroke over a four-stroke.
Lubricating oil is injected
where needed via a variable
ratio system that not only
alters the fuel/oil ratios
according to rpm but also
engine load, so a range of
ratios cannot be provided.
But the 2.3 litre integral oil
tank should provide more
than enough for a full
day of fishing, especially
when using fully synthetic
Evinrude/Johnson XD100
oil. As every engine is run
in the Sturtevant Wisconsin
factory, no formal break
in period is required. Just
as well, as most boaters I
know don’t run-in their new
engines, despite copious info
on how to do so in owner’s
manuals.
Power head access is good
with the fuel filter having a
replaceable element. And of
course, there’s no oil filter to
change. For full powerhead
access, the engine pan splitsin two.
Ever since the three years
“no servicing” concept was
promoted by BRP, there has
been debate amongst dealers
as to whether the engines
should be serviced more
frequently or not. Every
E-TEC dealer I’ve spoken with
has suggested changing
the gear oil annually and
greasing where needed. The
prop should be removed at
least annually, if not more
frequently, to check for any
stray fishing line around
the prop shaft which could
eventually “chew out” the
gear case seal. Prevention is
always better than cure!
The recreational usage
warranty is a total of five
years which compares with
the same period from Suzuki
and Tohatsu (four-strokes
only).ON THE WATER
The demo 75 was mounted
on a Stacer 475 Bay Master
owned by a family who
wanted the performance
of a carbie two-stroke with
four-stroke fuel eciency for
wakeboarding and fishing in
the NSW Snowy Mountains.
The family had owned carbie
two-strokes for years and
didn’t want the complexity
of a four-stroke. Swinging a
17-inch pitch alloy prop, the114 tradeaboat.com.au