more evenly distribute the pressure created during combustion; a fuel cooler;
and a low-maintenance oil-bathed self-adjusting timing chain. Like some other
outboards producing this much power,
the DF350A needs 91-octane fuel to
perform at its best.
90 shades of gray
Yamaha never seems to be satisfied, as
proven by its redesign of the ever-popular
F90 four-stroke, and a less powerful version, the F75. The engines benefit from
a 13-percent increase in displacement in
the form of 1. 8 liters as compared to the
previous versions’ 1. 6 liters. Yet weight
and overall size drop. Yamaha shaved off
13 pounds, bringing the F90 down to
353 pounds (362 pounds for the 25-inch
long-shaft version). Another change
Yamaha made was switching from a dual
overhead cam design to a single overhead
cam, which was what allowed the motor
to slim down in size.
When we ran the F90 (on an 18-foot
Xpress bay boat), we found that the
increase in displacement can be felt at
the helm – when you nail the throttle, the
engine releases a neck-snapping burst of
additional torque. We also noted a stingy
fuel burn of just under 5 gallons per hour
at a 4,500 rpm cruise.
Another intro of note for Yamaha this
year was the new F25. This model is not
only 25-percent lighter than last year’s
25-horse outboard, it’s also the lightest
25-horse outboard being produced today.
On top of that, this two cylinder, 26. 4
CID (cubic inch displacement) engine
has batteryless electronic fuel injection,
or EFI, which means one-pull starts
(though it did take us two tugs when we
didn’t yank vigorously enough) and most
importantly, as the fuel system is pres-
surized and contained, carburetor-related
ethanol issues become a thing of the past.
Finally, Yamaha also introduced a new
2.5-hp mini-might for use on dinghies
and very small boats. This is a one-cylinder 72 cc eggbeater that weighs in
at 37 pounds. The integrated fuel tank
holds 0.9 liters, and a pressurized leak-prevention system means you can lay it
down in your car’s trunk without fuel or
oil leaking out. The engine has forward
and neutral, and spins 180 degrees to
apply reverse power.
We haven’t seen any fresh power plants
from Evinrude or Mercury in the past
12 months, but both have introduced
new forms of control systems. Evinrude
rolled out its new-generation iDock joystick, designed to work with its E-TEC
G2 line. What gives this system a leg up
over most is the integration of an aircraft
gyro sensor, making the system smart
enough to compensate automatically for
wind and current. When we tested the
system on a pontoon boat and a center-console, we could tell the difference.
Added bonus: With an MSRP of $5,999,
iDock is significantly less expensive than
many competing outboard joystick-con-trol systems.
Mercury’s enhancements relate to
inboards, as opposed to its outboard line.
Joystick piloting for both single- and
twin-engine applications is now available for inboards, including Skyhook
with three new features: Heading
rolled out its next-generation iDock
joystick system for
its E-TEC G2 line.
also rolled out a
new diesel inboard
model this year
— the 6.7L in
480-, 500-, and
13 pounds off its
2018 POWER REPORT