quick specs
Yamaha 15FTYPE Loop-charged twin-
cylinder two-stroke outboard
RATED BHP/MHP* 14.7/15
at 5000rpm
WOT RPM RANGE 4500
to 5500
DISPLACEMENT 246cc
BORE X STROKE 56 x
50mm
GEAR RATIO 2.08:1
WEIGHT 36kg dry, short
shaft
RRP $2500
OEDA STARS 1
*Brake horsepower/metric
horsepower or PSseatrials
Single 15F on 1988 3.6m Sea Al Super Skua, swinging 10.5in prop and pushing a total of
295kg. Average of two-way runs on Lake Macquarie. Range is in nautical miles with a 10
percentreservefromthe24ltplastictotetank,roundedtothenearest whole number.THROTTLE OPENING/RPM SPEED (KTS) FUEL BURN (LT/H) RANGE (NM)
Trolling/850 2.5 0.6 90
Plane/half/3500 12.5 3.2 84
Cruise/two thirds/4000 14.9 3.6 89
Fast cruise/three-quarters/5000 19.7 4.9 87
WOT/6100 24.9 7.2 75“Loop” of cruising with 10 per cent WOT operation and averaging 8kts returned a fuel burn
of 2.7lt/h and a range of 64nm.and screw in the drain plug.
Quick and easy.
A relatively large-capacity
zinc anode is flush-fitted
under the anti-ventilation
plate and doesn’t interfere
with water flow around the
lower unit. The recreational-
warranty is three years.
ON THE WATER
The loan 15F was used on
only one hull over the eight
years I tested it and was a
perfect match for my 1988
3.6m Sea Al Super Skua
tinny. Swinging the standard
10.5in pitch alloy prop it
provided as much power as
I ever needed with excellent
cruising speeds and fuel
eiciency. As expected of a
loop-charged twin, vibration
levels trolling were fairly
high but not too much to
remove a lot of arm flab,
while noise levels were
reasonable up to 5000rpm.
Carefully run-in
according to Yamaha’s
recommendations using
standard (91 RON) unleaded
and Yamalube 2 oil, the loan
15F never let my partner of
12 years Susan or me down
on the many explorations
we took on Lake Macquarie.
Even during driving rain and
spray (how she ever tolerated
me for so long is a mystery)
the snug-fitting cowl with
aft-facing air intake never let
water reach the power head.
The cold-start system
worked flawlessly summer
or winter and the engine
always warmed quickly from
cold. Starting hot or cold
required just a firm one-hand
pull. Oddly, after 15 minutes
or more of trolling the engine
emitted oil smoke, even on
100:1, but throughout testing
the plugs remained clean.
Over eight years of testing,
three new waterpump
impellers and one thermostat
were fitted, I know not in
accordance with Yamaha’s
recommendations but this
amount of maintenance
seemed to do the job.
However, I learned the
hard way from one cooling
passage blockage due to
excess oil in the flushing
water never to use a drum
with a two-stroke 15 but
only mufs or rabbit ears to
ensure clean water is always
circulated through the
passages. No more blockages
after that mistake.
Reluctantly, because my
back was causing more
pain from lifting the 15F
from storage trolley to
transom, I sold the engine,
which was bought by the
first person who saw it forthe price asked. No doubt
about Yamahas, they have
excellent resale value.THE WRAP
Selling the 15F was hard and
of all the fifteens I’ve tested
over the years the 15F is still
my favourite!tradeboats.com.au 131