Boating

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HILE BIG SIX- AND EIGHT-CYLINDER OUTBOARDS MIGHT

grab the lion’s share of headlines, midrange outboards

represent the meat and potatoes of use by boaters.

Generally defi ned as outboards

ranging from 75 to 115 hp, this class

reigns as one of the most popular,

particularly on lakes and rivers in

Middle America where midrange

engines power many of today’s pon-

toon and aluminum fi shing boats.

Honda Marine’s new BF100 ups

the ante in the midrange arena. It

brings variable valve timing and lift

to the category and offers a host of

other advanced features, including

Lean Burn Control for greater fuel

effi ciency and Boosted Low Speed

Torque (BLAST) for better hole shot.

Weighing 360 pounds (dry with

a 20-inch shaft), the new inline four-

cylinder stands as the only 100 hp

outboard, giving it the best power-

to-weight ratio among competitive

90 hp four-strokes, nearly equaling

that of the two-stroke Evinrude 90.

The block and technology in the

BF100 evolved on the automotive

side of Honda and, in particular, in

Honda’s popular, high-mileage Fit

car. Honda’s VTEC variable valve

timing and lift, for example, was

born in cars, and it has proven to

enhance performance in four-stroke

outboards as well.

Introduced fi rst by Honda Marine

for its V-6 outboards, VTEC varies

the lift and duration of the open

intake valves to deliver optimal

performance at both low and high

rpm. This system uses two cam-lobe

profi les to operate the intake valves.

Low-lift, short-duration cam lobes

provide strong torque at low rpm. As

rpm increases, a piston engages a

rocker arm on a high-lift cam, lock-

ing all three rocker arms together. As

a result, the intake valves are open

for a longer period of time at higher

rpm to produce more power.

Honda calls this its replacement

for displacement. Indeed, the BF100’s

1.5-liter block produces 11 percent

more horsepower than outboards in

the 90 hp class, all of which possess

similar or greater displacement.

To further improve hole shot, the

BLAST system advances the spark-

plug timing and sets the air-to-fuel

mixture to a richer setting when the

throttle body for the Programmed

Fuel Injection system is opened

suddenly. This acts like a quick shot

of adrenaline to amplify the engine’s

low-end torque.

Honda’s new outboard also

features Lean Burn Control to

increase fuel effi ciency at cruising

speeds. An oxygen sensor monitors

the air-to-fuel ratio. Using that

data, the engine’s electronic brain

makes adjustments in the ratio,

leaning out the fuel when the engine

levels to a consistent midrange rpm.

Also helping effi ciency and speed

is a high-performance gear case

with a longer anti-ventilation plate

to minimize trapped water and help

eliminate porpoising. A front splash

Mighty Middle Weight

HONDA’S NEW BF100: THE REPLACEMENT FOR DISPLACEMENT

plate also reduces spray emanating

from the bottom of the boat hull.

A 2.33-to-1 gear ratio allows the

BF100 to use 13- to 14-inch-diameter

propellers to lift heavier loads.

To help power marine electronics,

livewell pumps and other accessories,

the alternator develops 44 amps

in total, with 35 of those amps

dedicated to powering onboard

equipment and charging batteries.

Anglers who troll will love the

Honda BF100. The motor’s push-

button troll-speed control lets you

fi ne-tune the pace in 50 rpm incre-

ments from 650 to 1,000 rpm. The

feature is standard in tiller models

and optional on engines with

remote throttle and shift.

Honda has not forgotten coastal

boaters. The BF100 comes with a

multifaceted corrosion-protection

system that includes a paint process

using four different layers to protect

the aluminum-alloy housings. In

addition, multiple sacrifi cial anodes

guard against galvanic corrosion.

Freshwater fl ush ports let you rinse

salt and other contaminants from

internal cooling passages with a

garden hose.

The Honda BF100 features

NMEA 2000 connectivity, allowing

you to network the engine systems

with onboard marine electronics

and view engine parameters on

compatible multifunction displays.

— Jim Hendricks

PHOTOS: (FROM TOP) COURTESY HONDA MARINE, COURTESY MERCURY MARINE

Mercury’s New 115 Pro XS

Mercury Marine says its new 115 Pro XS high-output four-

stroke outboard is 16 pounds lighter than the two-stroke it

replaces. At about 360 pounds, the 2.1-liter engine weighs

18 pounds less than the nearest competing 115. Merc has also

boosted the battery-charging capacity at idle. — J.H.

HONDA BF100

HORSEPOWER: 100

MAX-RATED RPM: 6,300

DISPLACEMENT: 1.5L/91.4 cid

COMPRESSION RATIO: 9.7:1

GEAR RATIO: 2.33:1

WEIGHT (20", DRY): 360 lb.

Motorhead

64 BOATINGMAG.COM APRIL 2016