United States

Environmental Protection

 Agency

EPA420-F-98-025

August 1998

Office of Mobile Sources

Small Engine Emission Standards

Answers to

Commonly

Asked Questions

from Dealers

and Distributors

This brochure provides

information about the U.S.

Environmental Protection

Agency’s (EPA) new emission

standards for small sparkignition engines of 25

horsepower or less and

answers some commonly

asked questions about the

new regulation.

Why Is EPA Regulating These Engines?

In many ways, the U.S. has been successful in cleaning

the air, but we still have serious air pollution problems in

many parts of the country—especially in large urban

areas. Most people think of air pollution control programs

in the U.S. as strict emission standards for cars, trucks,

and large industrial facilities. In 1990, Congress asked

EPA to look at other sources of air pollution such as

nonroad mobile sources, including recreational vehicles,

farm and construction equipment, boats, locomotives, and

lawn and garden power equipment. Subsequently, EPA

has been developing emission standards for virtually all

types of nonroad equipment.

As part of that effort, EPA is implementing a regulation

that establishes emission standards for small sparkignition engines of 25 HP (19 kW) or less. These small

spark-ignition engines are predominantly in lawn and

garden power equipment and in some farm, construction

and utility equipment.

Until recently, small engines of this type were not regulated at all except in California. According to EPA

estimates, in many large urban areas, pre-1997 lawn and

garden equipment accounts for as much as 5 percent of

the total man-made hydrocarbons that contribute to ozone

formation. EPA expects that reducing emissions from

small engines will help to alleviate the formation of

ground-level ozone—resulting in a decrease of air

pollution-related health problems for urban residents.

Why Are Emissions from Small Engines

Harmful?

Small engines used in power equipment emit a variety of

pollutants. These include hydrocarbons and oxides of

nitrogen (NOx), which lead to the production of groundlevel ozone, the principal component of smog. Ozone can

impair human lung functions and inhibit plant growth. In

addition, NOx contributes to the production of acid rain.

These engines also produce carbon monoxide, a colorless,

odorless and poisonous gas which results from incomplete fuel combustion. Infants and people with heart

disease or respiratory problems are especially sensitive to

carbon monoxide poisoning.

How Much Cleaner Are the New Engines?

Compared to their unregulated counterparts, EPA estimates that engines complying with the new emission

standards will emit on average more than one third less

hydrocarbons.

How Does the Small Engine Rule Work?

The regulation

(commonly called

Phase 1) sets allowable exhaust levels

for hydrocarbons,

carbon monoxide,

and NOx from small

engines of 25 HP or

less. The rule applies

to all small engines

produced after

September 1, 1997—with some earlier and a few later.

Allowable emission levels vary depending on engine size

and use.

EPA works directly with the engine manufacturers to

assure they comply with the regulations. Before an engine

manufacturer can sell a regulated engine model in the

U.S., it must obtain a certificate of conformity from EPA.

To obtain a certificate of conformity, the engine manufacturer must provide test data along with other information

demonstrating that the engine model meets the applicable

emission standards.

The Agency requires that the engine manufacturer label

each certified engine to indicate compliance with the

small spark-ignition engine rule. The language may read

“this engine conforms to Phase 1 U.S. EPA regulations

for small nonroad engines.” Some engine labels, however,

will feature language indicating compliance with both

EPA and California regulations. Emission labels will be

found on the engine, or if the engine label is obscured, on

the piece of equipment itself.

Responsibilities for Dealers Performing

Maintenance

What are my liabilities as a dealer? Tampering with a

certified small engine is against the law. Having knowledge of the rules regarding tampering is important. You
may be tampering (and consequently subject to civil

penalties) if you knowingly disable an emission control

system component or element of design of a certified

engine. This could include adjusting the engine’s fuel or

exhaust system or changing the engine’s performance so

it no longer meets the manufacturer’s specifications. It

could also include the improper venting of crankcase

emissions. You may also be tampering by installing a part

that is not the same in design and function as the part

originally installed, or adding a new part not originally

certified with the engine.

Will I be required to use manufacturers’ parts when

servicing? No. You can also use new or rebuilt parts made

by an independent parts manufacturer as long as they

conform with the original parts in design and function.

Some part manufacturers provide a list of engine models

that the part can be used on—you will most likely see this

list somewhere on the part’s packaging. If the manufacturer does not provide this list, you can still use the part as

long as a

person

familiar with

the design

and function

of small

engines

would

reasonably

believe that

the part is

designed to

perform the

same functions as the original part. However, using an

aftermarket part that does not conform with the original

part in design and function may void a customer’s emissions warranty.

Do the regulations affect older equipment? No. The

regulations only affect new engines produced for the 1997

model year and later. For example, if an owner brings in a

piece of equipment containing an engine manufactured in

1994 for servicing, EPA does not require that the repair

technician alter the engine so that it meets Phase 1

standards since the engine was produced before the rule

took effect.

What should I do if a unit comes in for repair that has

evidence of tampering?

EPA encourages repair technicians to restore a tampered

engine to its original certified configuration. However,

repair technicians are not required to restore tampered

products to their originally certified and functioning

configuration, unless the repair is to the tampered system.

In such a case, the repair technician should restore the

system to a certified and properly functioning condition.

Basically, if a repair facility completes, assists, or participates in any way to tampering begun by someone else,

they may be subject to civil penalties. In order to protect

yourself and your repair facility, you should always

document pre-existing tampering in writing on the service

order. You are not required to notify EPA about the

noncompliance, but you can help raise customer awareness by informing your customers that tampering is illegal

and that it may reduce the life span and performance of

the engine.

Customers Questions

Will emissions regulations result in a higher cost for

equipment? According to EPA analysis, the small engine

regulation will increase the cost of equipment by an

average of $5-7 per unit, but durability will improve and

fuel efficiency will increase for most small engines. These

improvements in engine technology may offset the

increase in cost.

Can I make adjustments to the new engines at home?

Consumers should perform routine use and care maintenance as recommended in the operator’s manual. However, owners should contact a qualified engine technician

for adjustments not listed in the operator’s manual.

Owners should also be aware that it is against the law to

tamper with an EPA-certified small engine. Tampering

with a certified engine may involve adjusting the fuel or

exhaust system, or changing the engine’s performance so

that it no longer meets the manufacturer’s specifications.

Tampering may increase an engine’s exhaust emissions,

contributing to our air pollution problems. To stop customers and repair facilities from tampering, manufacturers

have equipped many engines with special caps or plugs

that limit or prevent adjusting the fuel mixture or engine

timing. Removal of these special caps or plugs and

adjustments beyond the manufacturers specified limits are

considered tampering and may subject the violator to a

fine.

What is an emission warranty? Manufacturers are

required by Federal law to provide emission warranty

coverage for small spark-ignition engines. Basically, this

warranty covers repair of emission control related parts

that are determined to be defective during the first two

years of engine use. Emission control related parts

include 1) any part whose primary purpose is to control

emissions, such as a catalytic converter, and 2) any part

that has an effect on emissions, such as a carburetor.

Owners will find that small engine manufacturers have

established procedures to provide owners with this

warranty coverage. If an owner or repair technician

suspects that an emission control related part is defective,

they should contact the person identified by the manufacturer in the owner’s manual or warranty book. Owners of

small spark-ignition engines are responsible for the

proper maintenance of their engine. They can either

perform scheduled maintenance themselves or have a

repair technician perform it for them. Written instructions

that describe an engine’s proper maintenance, will be

found in the owner’s manual. If a part failure is a direct

result of the engine not being maintained or used according to the manufacturer’s recommendations, the manufacturer may not be required to cover the repair or replacement of the failed part.

What else can I do to reduce emissions?

One of the most simple and effective ways to reduce

emissions is to avoid spilling gasoline when refilling gas

cans and equipment tanks. When gasoline is spilled,

hydrocarbons are released into the air, contributing to our

air pollution problem. Owners can also help cut emissions

while improving their engine performance by regularly

maintaining their engines. When owners fail to do this,

fuel efficiency drops while pollution rises.

For More Information

For more information about EPA efforts to reduce emissions from small spark-ignition engines, you can contact

the U.S. EPA Engine Compliance Group, 401 M St. SW,

(6403J) Washington, DC 20460—(202) 564-9261—or

check the website at www.epa.gov/oms.

For additional copies of this brochure, please call the

National Center for Environmental Publications and

Information (NCEPI) at (800) 490-9198.