16
EMISSION CONTROL SYSTEM

Source of Emissions

The combustion process produces carbon monoxide, oxides of
nitrogen, and hydrocarbons. Control of hydrocarbons and oxides of
nitrogen is very important because, under certain conditions, they
react to form photochemical smog when subjected to sunlight. Carbon
monoxide does not react in the same way, but it is toxic.
Honda utilizes appropriate air/fuel ratios and other emissions control
systems to reduce the emissions of carbon monoxide, oxides of
nitrogen, and hydrocarbons. Additionally, Honda fuel systems utilize
components and control technologies to reduce evaporative
emissions.

The U.S., California Clean Air Act and Environment

Canada

EPA, California, and Canadian regulations require all manufacturers
to furnish written instructions describing the operation and
maintenance of emissions control systems.
The following instructions and procedures must be followed in order to
keep the emissions from your Honda engine within the emissions
standards.

Tampering and Altering

Tampering with or altering the emissions control system may increase
emissions beyond the legal limit. Among those acts that constitute
tampering are:
• Removing or altering any part of the intake, fuel, or exhaust
systems.
• Altering or defeating the speed-adjusting mechanism to cause the
engine to operate outside its design parameters.

Problems That May Affect Emissions

If you are aware of any of the following symptoms, have your engine
inspected and repaired by your servicing dealer.
• Hard starting or stalling after starting
• Rough idle
• Misfiring or backfiring under load
• Afterburning (backfiring)
• Black exhaust smoke or high fuel consumption

Replacement Parts

The emissions control systems on your new Honda engine were
designed, built, and certified to conform with EPA, California, and
Canadian emissions regulations. We recommend the use of genuine
Honda parts whenever you have maintenance done. These
original-design replacement parts are manufactured to the same
standards as the original parts, so you can be confident of their
performance. The use of replacement parts that are not of the original
design and quality may impair the effectiveness of your emissions
control system.
A manufacturer of an aftermarket part assumes the responsibility that
the part will not adversely affect emissions performance. The
manufacturer or rebuilder of the part must certify that use of the part
will not result in a failure of the engine to comply with emissions
regulations.

Maintenance

Follow the MAINTENANCE SCHEDULE on page 8. Remember this
schedule is based on the assumption that your machine will be used
for its designed purpose. Sustained high-load or high-temperature
operation or use in unusually wet or dusty conditions will require more
frequent service.
AIR INDEX
An Air Index Information hang tag/label is applied to engines certified
to an emission durability time period in accordance with the
requirements of the California Air Resources Board.
The bar graph is intended to provide you, our customer, the ability to
compare the emissions performance of available engines. The lower
the Air Index, the less pollution.
The durability description is intended to provide you with information
relating the engine’s emission durability period. The descriptive term
indicates the useful life period for the engine’s emission control
system. See your Emission Control System Warranty (page 19) for
additional information.
The Air Index Information hang tag/label must remain on the lawn
mower until it is sold. Remove the hang tag before operating the lawn
mower.
SPECIFICATIONS

Mower Model

Maintenance

Descriptive Term Applicable to Emissions
Durability Period
Moderate 50 hours (0 ~ 80 cc)
125 hours (greater than 80 cc)
Intermediate 125 hours (0 ~ 80 cc)
250 hours (greater than 80 cc)
Extended 300 hours (0 ~ 80 cc)
500 hours (greater than 80 cc)
1000 hours (225 cc and greater)
HRX217VKAA
Honda rotary mower, grass bag,
21 inch mower deck, Clip Director,
variable speed transmission, flywheel
brake, fully automatic choke, USA
market
Fuel Unleaded gasoline with a pump
octane rating of 86 or higher. page 12
Engine Oil
SAE 10W-30, API SJ or later
*Refill amount: 12.0 ~ 13.5 oz
(0.35 ~ 0.40 )
page 10
Spark Plug Type
Regular: NGK BP6ES
DENSO W20EP-U
Resistor: NGK BPR6ES
DENSO W20EPR-U
page 11
Maximum
Governed Speed **2,950 ~ 3,100 rpm Shop
manual
Blade Bolt Torque 36 ~ 43 ft-lb (49 ~ 59 N•m) page 9
* Actual amount will vary based on residual oil in the engine.
Always use the dipstick to confirm the actual level (see page 10).
** Do not try to increase the engine speed above the maximum
governed speed; the blades could fracture and come apart.