GASOLINE ENGINES
The middle model of three
new mid GX gasoline
engines recently intro-
duced by Honda Engines,
is the GX160, a single-
cylinder, OHV design with
an output of 4. 8 hp.
Step 3: Honda
Introduces Mid
GX Engines
BY MIKE OSENGA
Theannual Worldof Concrete show has been a popular venue for Honda Engines
in recent years. Using the forum
provided by the annual off-highway
equipment show, the Alpharetta,
Ga.-based manufacturer has completed what, in essence, has been
a three-step overhaul of its entire
industrial gasoline engine range,
from 120 to 688 cc, since 2009.
At the 2009 World of Concrete,
Honda launched six new V-twin general-purpose engines. That was followed by the February 2010 World
of Concrete introduction of larger
models in the GX and iGX series, a
launch that featured four new overhead valve, horizontal shaft engines.
Now this January, again at World of
Concrete, Honda made engine news
with the launch of its all-new mid
GX engines line. Completely rede-
signed for 2011, the new GX120, the
GX160 and the GX200 are single-
cylinder, horizontal-shaft engines that
replace the existing GX120, GX160
and GX200 models.
In terms of the performance increases, fuel economy has been improved
through changes in valve timing, compression ratio, carburetor settings and
cooling system modifications.
Meanwhile, noise levels have been
reduced through changes in muffler
structure design, breather valve, push
rod materials and crankcase cover
rigidity, with reduced vibration achieved
through use of a lighter engine piston.
Finally, the company said emissions compliance has been accomplished in part through changes in
valve timing, carburetor settings and
other proprietary components.
Honda said the new Honda mid
GX120, GX160 and GX200 engines
meet EPA Phase 3 exhaust and evaporative emissions that will take effect in
2011 or 2012, depending on the size of
the engine. The final rule also includes
new standards to reduce evaporative
emissions from these fuel systems.
The design configuration of the new
Honda mid GX models reduces hydrocarbon (HC) emissions and NOx while
maintaining the same level of output
power as the previous Honda GX
models they replace, Rudolph said.
“The engines reduce HCs by reduc-
ing oil consumption via a redesigned
piston shape and piston ring along with
a modified carburetor setting,” he said.
“In addition, the engine design reduces
NOx emissions through an adjustment
in ignition timing, which reduces com-
bustion temperature and pressure.”
The new mid GX engines also have
a number of other design enhance-
ments, including a new carburetor
chamber coating, a recoil rope design
change, the addition of a carburetor
filter and an improved fuel tank.
With an eye on noise and vibration reduction in the new midrange
GX160 engines, the composition of
the push rods has been changed
from steel to aluminum.
Because the cylinder heads also are
constructed from aluminum, this design
change equalizes the linear expansion
coefficient of the push rods, Rudolph
said. This reduces the valve clearance
and reduces the tappet noise. The new
