Engine Emissions Education – Gas

Some say the rules never change. Others insist rules are made to be broken. The fact is, rules and regulations affect our actions and daily activities — from the way we drive to how we perform our jobs. Everyone in the equipment industry is growing more aware of the evolving emission regulations surrounding engines and equipment recently, from small generators to large excavators.

Considering smaller scale equipment, the new U.S. Environmental Protection Agency (EPA) Phase 3 emission regulations for gas-powered equipment (implemented at the start of 2012) have impacted manufacturers, distributors, dealers, OEMs, repair shops, rental centers and, as a result, end-users. Last year, all small spark-ignition engines greater than 225cc were impacted. This year, the regulation includes all engines smaller than 225cc. By next year, all gas-powered equipment will need to be certified by the EPA.

All of these requirements are rolled into Title 40 of the U.S. Code of Federal Regulations under Sections 40 CFR 1054 and 40 CFR 1060. To really understand what it all means, let’s break that down into something a little easier to digest.

What It’s About


Everyone has smelled gas while opening a fuel container on a warm day; that smell is the vapor, which the new regulations address. The California Air Resources Board (CARB) has regulated evaporative emissions from equipment powered by small gas engines for years. According to the EPA, small engines will emit about one-third fewer hydrocarbons under the new standards. The regulations aim to control running losses and permeation losses from fuel systems. Many people are surprised to learn just how much fuel vapor passes through the walls of untreated plastic fuel containers alone.

Permeation is just one way in which fuel vapors are emitted, though. Evaporative emissions occur when an engine is running as well as through diurnal loss, when the engine isn’t running, due to daily temperature changes. Each equipment builder must control evaporative emissions from fuel systems and get equipment certified with the EPA. This trickles down to the end-user, who needs to be aware of how the changes affect the product they are using and servicing.

What It Looks Like


Some manufacturers have been ahead of the game in improving products to meet the standards. Those manufacturers employ a number of methods to control evaporative emissions, from special hoses and fuel caps on sealed fuel tanks to carbon canisters and vapor control valves. Here’s a breakdown of what that looks like inside any new gas-powered equipment a consumer may purchase: Hoses that come in direct contact with liquid gasoline must now be special low-permeation fuel hoses, which are manufactured specifically to limit the amount of fuel vapors that permeate through the hose wall.

Vented fuel caps have been primarily replaced with sealed caps to prevent evaporative emissions. When a sealed cap is used, there will be different hose connections. In addition to the normal fuel hose connection at the bottom of the tank, there also will be a connection for the vapor hose at either the top or bottom of the tank.

There’s one exception to the sealed fuel cap on some small engines, though. In those cases, the fuel cap self-vents through a carbon canister. The canisters come in different shapes and sizes and may be anywhere on the equipment. The carbon canister works to absorb diurnal vapors. When the engine runs, an intake vacuum draws vapors from the tank into the engine, where it is burned. After the engine is shut off, vapors continue to be emitted into the atmosphere due to temperature changes throughout the day. The carbon canister absorbs those vapors, and when the engine is started again, the engine intake vacuum will draw in fresh air through the carbon canister’s vent port and thus purge the stored vapors.

Some engine manufacturers also are incorporating optional vapor control valves, or “rollover valves,” in new systems. These devices prevent liquid fuel from getting into the vapor system.

What’s Now Required


OEMs must complete several steps to ensure adherence to the EPA’s regulations. This includes registering through the EPA’s Verify information system. The Verify system collects data on emissions and fuel economy compliance for all sizes of engines. Each manufacturer must register with the EPA and apply for evaporative certification through Verify. Manufacturers cannot sell equipment until obtaining the certificate, so any new equipment purchased will meet the new standards.

Under the new regulations, manufacturers also will need to place a permanently affixed approved evaporative emissions label on the equipment. This label will include the manufacturer’s corporate name and trademark, the EPA’s standardized designation for the emission family and the manufacture date. The EPA also requires that the label include the emissions compliance period over which the engine exhaust emissions system was tested and a statement certifying that the engine meets exhaust emission regulations.

Each piece of new equipment also must come with an approved evaporative emissions warranty statement. Under this requirement, buyers will know that the engine meets two conditions. First, at the time of sale the engine meets EPA regulations and, second, that there are no defects to keep the engine from meeting emission standards. The EPA requires a minimum two-year emission-related warranty. The warranty covers any component that, should it fail, would increase the engine’s emissions of a regulated pollutant.

What Can’t Be Done


First and foremost, don’t attempt to modify engines designed to meet EPA standards. Placing a new sealed fuel cap on an older pre-EPA fuel system will cause fuel starvation. Placing a vented cap on a new EPA-certified fuel system will cause uncontrolled emission losses, plus it’ll be in violation of EPA regulations. Finally, don’t try to replace a carbon canister cap with a standard cap.

What Can Be Done

The manufacturer should provide a list of any critical emission-related maintenance as well as other recommended maintenance and the corresponding schedules. It’s still acceptable to use new or rebuilt parts as long as they meet the engine’s original specifications. Following basic manufacturer guidelines and replacing parts with like parts will ensure the greatest return on investment.

In terms of the warranty, each new engine sold will offer at least two years of warranty coverage on its emission components. The warranty covers the repair of emission-control-related parts that are found to be defective within the first couple of years of service. Ensure none of these parts are tampered with since that may void the warranty. Any piece of rental equipment that has survived the long haul and predates EPA emission standards won’t need to be altered.


Pam Meyer is the equipment sales manager at Subaru Industrial Power Products, based in Lake Zurich, Ill.

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  • Many people are oagruted about this, and California has announced it will appeal the EPA’s decision. The appeal will go to the federal appeals court in Washington, where there is a good chance the decision will be overturned.Since the EPA is an administrative agency controlled by the executive branch, it’s no surprise that it doesn’t do much to protect the earth when the President is taking advice on the environment from people like . Let’s hope there are some positive changes in the white house after the next election.In the meantime, we can all do everything possible to work for change on a grassroots level. The little things we do make a difference, and they have ripple effects beyond the immediate benefits. For example, I ride my bike to my son’s elementary school to volunteer. It saves a little gas, but more importantly, I think it has changed some attitudes. The first day I showed up carrying a bike helmet, a woman at the front desk gave me a “who are you, and WTF are you doing here?” kind of look, but now she smiles at me. The kids in my son’s class know that I ride a bike even though I have a car, and they know why I do it. Every little bit helps.So vote, keep doing what you can in your own life, and don’t let the blankety-blank politicians drag you down.