Wiseman Towing

Water and wastewater treatment plant and system operators manage a system of machines, often through the use of control boards, to transfer or treat water or wastewater.

Water and wastewater treatment plant and system operators typically do the following:

• Add chemicals, such as ammonia, chlorine, or lime, to disinfect water or other liquids
• Inspect equipment on a regular basis
• Monitor operating conditions, meters, and gauges
• Collect and test water and sewage samples
• Record meter and gauge readings and operational data
• Operate equipment to purify and clarify water or to process or dispose of sewage
• Clean and maintain equipment, tanks, filter beds, and other work areas
• Stay current on U.S. Environmental Protection Agency regulations
• Ensure safety standards are met

It takes a lot of work to get water from natural sources--reservoirs, streams, and groundwater--into our taps. Similarly, it is a complicated process to convert the wastewater in our drains and sewers into a form that is safe to release into the environment.

The specific duties of plant operators depend on the type and size of the plant. In a small plant, one operator may be responsible for maintaining all of the systems. In large plants, multiple operators work the same shifts and are more specialized in their duties, often relying on computerized systems to help them monitor plant processes.

Occasionally, operators must work during emergencies. For example, weather conditions may cause large amounts of storm water or wastewater to flow into sewers, exceeding a plant's capacity. Emergencies also may be caused by malfunctions within a plant, such as chemical leaks or oxygen deficiencies. Operators are trained in emergency management procedures and use safety equipment to protect their health, as well as that of the public.

Water treatment plant and system operators work in water treatment plants. Fresh water is pumped from wells, rivers, streams, and reservoirs to water treatment plants, where it is treated and distributed to customers. Water treatment plant and system operators run the equipment, control the processes, and monitor the plants that treat water to make it safe to drink.

Wastewater treatment plant and system operators do similar work to remove pollutants from domestic and industrial waste. Used water, also known as wastewater, travels through sewage pipes to treatment plants where it is treated and either returned to streams, rivers, and oceans, or used for irrigation.

Automotive body and glass repairers restore, refinish, and replace vehicle bodies and frames, windshields, and window glass.

Automotive body and glass repairers typically do the following:

• Review damage reports, prepare cost estimates, and plan work
• Remove damaged body parts, including bumpers, fenders, hoods, grilles, and trim
• Realign car frames and chassis to repair structural damage
• Hammer out or patch dents, dimples, and other minor body damage
• Fit, attach, and weld replacement parts into place
• Install and weatherproof windows and windshields
• Grind, sand, buff, and prime refurbished and repaired surfaces
• Apply new finish to restored body parts

Automotive body and glass repairers can repair most damage from everyday vehicle collisions and make vehicles look and drive like new. Damage may be minor, such as replacing a cracked windshield, or major, such as replacing an entire door panel.

Repair technicians use many tools for their work. To remove damaged parts, such as bumpers and door panels, they use pneumatic tools, metal-cutting guns, and plasma cutters. For major structural repairs, such as aligning the body, they often use heavy-duty hydraulic jacks and hammers. For some work, they use common handtools, such as metal files, pliers, wrenches, hammers, and screwdrivers.

In some cases, repair technicians do an entire job by themselves. In other cases, especially in large shops, they use an assembly line approach in which they work as a team with each repair technician specializing.

Although repair technicians sometimes prime and paint repaired parts, automotive painters generally perform these tasks. For more information, see the profile on painting and coating workers.

The following are occupational specialties: 

Automotive body and related repairers, or collision repair technicians, straighten metal panels, remove dents, and replace parts that cannot be fixed. Although they repair all types of vehicles, most work primarily on cars, sport utility vehicles, and small trucks. 

Automotive glass installers and repairers remove and replace broken, cracked, or pitted windshields and window glass. They also weatherproof newly installed windows and windshields with chemical treatments.

Heavy vehicle and mobile equipment service technicians inspect, maintain, and repair vehicles and machinery used in construction, farming, rail transportation, and other industries.

Heavy vehicle and mobile equipment service technicians typically do the following:

• Read and understand operating manuals, blueprints, and drawings
• Perform scheduled maintenance, such as cleaning and lubricating parts
• Diagnose and identify malfunctions, using computerized tools and equipment
• Inspect, repair, and replace defective or worn parts, such as bearings, pistons, and gears
• Overhaul and test major components, such as engines, hydraulics, and electrical systems
• Disassemble and reassemble heavy equipment and components
• Travel to worksites to repair large equipment, such as cranes

Heavy vehicles and mobile equipment are critical to many industrial activities, including construction and railroad transportation. Various types of equipment, such as farm machinery, cranes, and bulldozers, are used to move materials, till land, lift beams, and dig earth to pave the way for development and construction.

Heavy vehicle and mobile equipment service technicians repair and maintain engines, hydraulic systems, transmissions, and electrical systems of agricultural, industrial, construction, and rail equipment. They ensure the performance and safety of fuel lines, brakes, transmissions, and other systems.

With many types of equipment and mechanical and electrical systems, service technicians use diagnostic computers to identify problems and make adjustments or repairs. Although the use of computerized testing equipment, such as tachometers and dynamometers, is common, technicians also use many different power and machine tools, including pneumatic wrenches, lathes, and welding equipment.

Service technicians also use many different handtools, such as screwdrivers, pliers, and wrenches, to work on small parts and in hard-to-reach areas. They generally purchase these tools over the course of their careers, often investing thousands of dollars in their collections.

After locating malfunctions, service technicians repair, replace, and recalibrate components such as hydraulic pumps or spark plugs. This may involve disassembling and reassembling major equipment or making adjustments through an onboard computer program.

The following are types of heavy vehicle and mobile equipment service technicians:

Farm equipment mechanics service and repair farm equipment, such as tractors and harvesters. They also work on smaller consumer-grade lawn and garden tractors. Most mechanics work for dealer repair shops, where farmers increasingly send their equipment for maintenance.   

Mobile heavy equipment mechanics repair and maintain construction and surface mining equipment, such as bulldozers, cranes, graders, and excavators. Many work for equipment wholesale and distribution shops and large construction and mining companies. Those working for the federal government may work on tanks and other military equipment.

Rail car repairers specialize in servicing railroad locomotives, subway cars, and other rolling stock. They usually work for railroad, public and private transit companies, and rail car manufacturers.

For information about technicians and mechanics who work primarily on automobiles, see the profile on automotive service technicians and mechanics.

For information about technicians who work primarily on large trucks and buses, see the profile on diesel service technicians and mechanics.

For information about technicians and mechanics who primarily work on motorboats, motorcycles and small all-terrain vehicles, see the profile on small engine mechanics.

Police officers protect lives and property. Detectives and criminal investigators, who sometimes are called agents or special agents, gather facts and collect evidence of possible crimes. Law enforcement officers' duties depend on the size and type of their organizations.

Uniformed police officers typically do the following:

• Enforce laws
• Respond to calls for service
• Patrol assigned areas
• Conduct traffic stops and issue citations
• Arrest suspects
• Write detailed reports and fill out forms
• Prepare cases and testify in court

Detectives and criminal investigators typically do the following:

• Investigate crimes
• Collect evidence of crimes
• Conduct interviews with suspects and witnesses
• Observe the activities of suspects
• Arrest suspects
• Write detailed reports and fill out forms
• Prepare cases and testify in court

Police officers pursue and apprehend people who break the law and then warn them, cite them, or arrest them. Most police officers patrol their jurisdictions and investigate any suspicious activity they notice. They also respond to calls, issue traffic tickets, investigate domestic issues, and give first aid to accident victims.

Detectives perform investigative duties such as gathering facts and collecting evidence.

The daily activities of police and detectives vary with their occupational specialty and whether they are working for a local, state, or federal agency. Duties also differ among federal agencies, which enforce different aspects of the law. Regardless of job duties or location, police officers and detectives at all levels must write reports and keep detailed records that will be needed if they testify in court.

The following are examples of types of police and detectives who work in state and local law enforcement and in federal law enforcement:

State and Local Law Enforcement

Uniformed police officers have general law enforcement duties. They wear uniforms that allow the public to easily recognize them as police officers. They have regular patrols and also respond to calls for service.

Police agencies are usually organized into geographic districts, with uniformed officers assigned to patrol a specific area. Officers in large agencies often patrol with a partner. During patrols, officers look for any signs of criminal activity and may conduct searches or arrest suspected criminals. They may also respond to emergency calls, investigate complaints, and enforce traffic laws.

Some police officers work only on a specific type of crime, such as narcotics. Officers, especially those working in large departments, may also work in special units, such as horseback, motorcycle, and canine corps or special weapons and tactics (SWAT) teams. Typically, officers must work as patrol officers for a certain number of years before they may be appointed to one of these units.

Many city police agencies are involved in community policing, a philosophy of bringing police and members of the community together to prevent crime. A neighborhood watch program is one type of community policing.

Some agencies have special geographic and enforcement responsibilities. Examples include public college and university police forces, public school district police, and transit police. Most law enforcement workers in special agencies are uniformed officers.

State police officers, sometimes called state troopers or highway patrol officers, have many of the same duties as other police officers, but they may spend more time enforcing traffic laws and issuing traffic citations. State police officers have authority to work anywhere in the state and are frequently called on to help other law enforcement agencies, especially those in rural areas or small towns. State highway patrols operate in every state except Hawaii.

Transit and railroad police patrol railroad yards and transit stations. They protect property, employees, and passengers from crimes such as thefts and robberies. They remove trespassers from railroad and transit properties and check the IDs of people who try to enter secure areas.   

Sheriffs and deputy sheriffs enforce the law on the county level. Sheriffs' departments tend to be relatively small. Sheriffs usually are elected by the public and do the same work as a local or county police chief. Some sheriffs' departments do the same work as officers in urban police departments. Others mainly operate the county jails and provide services in the local courts. Police and sheriffs' deputies who provide security in city and county courts are sometimes called bailiffs.

Detectives and criminal investigators are plainclothes investigators who gather facts and collect evidence for criminal cases. They conduct interviews, examine records, observe the activities of suspects, and participate in raids or arrests. Detectives usually specialize in investigating one type of crime, such as homicide or fraud. Detectives are typically assigned cases on a rotating basis and work on them until an arrest and conviction is made or until the case is dropped.

Fish and game wardens enforce fishing, hunting, and boating laws. They patrol hunting and fishing areas, conduct search and rescue operations, investigate complaints and accidents, and educate the public about laws pertaining to their environment.

Federal Law Enforcement

Federal law enforcement officials carry out many of the same duties that other police officers do; however, they have jurisdiction over the entire country. Many federal agents are highly specialized. The following are examples of federal agencies in which officers and agents enforce particular types of laws.

• Federal Bureau of Investigation (FBI) agents are the federal government's principal investigators, responsible for enforcing more than 300 federal statutes and conducting sensitive national security investigations.
• U.S. Drug Enforcement Administration (DEA) agents enforce laws and regulations relating to illegal drugs.
• U.S. Secret Service uniformed officers protect the President, the Vice President, their immediate families, and other public officials.
• Federal Air Marshals provide air security by guarding against attacks targeting U.S. aircraft, passengers, and crews.
• U.S. Border patrol agents protect international land and water boundaries.

See the Contacts for More Information section for more information about federal law enforcement agencies.

Automotive service technicians and mechanics, often called service technicians or service techs, inspect, maintain, and repair cars and light trucks.  

Automotive service technicians and mechanics typically do the following:

• Test parts and systems to ensure that they are working properly
• Identify mechanical problems, often by using computerized diagnostic equipment
• Follow checklists to ensure that all critical parts are examined
• Test and lubricate the vehicle's engine and other major components
• Perform basic care and maintenance, including oil changes, tuneups, and tire rotations
• Repair or replace worn parts, such as brake pads and wheel bearings
• Disassemble and reassemble parts
• Use testing equipment to ensure that repairs and maintenance are effective
• Explain to clients their automotive problems and the repairs done on their vehicles

Service technicians work on traditional mechanical components, such as engines, transmissions, belts, and hoses. However, they must also be familiar with a growing number of electronic systems. Braking, transmission, and steering systems, for example, are controlled primarily by computers and electronic components.

Other integrated electronic systems, such as accident-avoidance sensors, are becoming common as well. In addition, a growing number of technicians are required to work on vehicles that run on alternative fuels, such as ethanol and electricity.

Service technicians use many different tools, including computerized diagnostic tools and power tools such as pneumatic wrenches, lathes, welding torches, and jacks and hoists. These tools usually are owned by their employers.

Service technicians also use many common handtools, such as pliers, wrenches, and screwdrivers, which generally are their own. In fact, experienced workers often have thousands of dollars invested in their personal tool collection.

Service technicians sometimes specialize in a particular type of repair that may be subject to specific regulations or procedures. For instance, those focused on air-conditioning system repairs must follow federal and state regulations governing the handling, recycling, and disposal of refrigerants.

In some shops, technicians may specialize. The following are types of service technicians:

Automotive air-conditioning repairers install and repair air conditioners and service parts, such as compressors, condensers, and controls. They are trained in government regulations related to their work.

Brake repairers adjust brakes, replace brake linings and pads, and make other repairs on brake systems. Some technicians specialize in both brake and front-end work. 

Front-end mechanics align and balance wheels and repair steering mechanisms and suspension systems. They frequently use special alignment equipment and wheel-balancing machines.

Transmission technicians and rebuilders work on gear trains, couplings, hydraulic pumps, and other parts of transmissions. Extensive knowledge of computer controls, the ability to diagnose electrical and hydraulic problems, and other specialized skills are needed to work on these complex components.

Tune-up technicians adjust ignition timing and valves and adjust or replace spark plugs and other parts to ensure efficient engine performance. They often use electronic testing equipment to isolate and adjust malfunctions in fuel, ignition, and emissions control systems.

For information about technicians who work on large trucks and buses, see the profile on diesel service technicians and mechanics.

For information about technicians who work on farm equipment, construction vehicles, and rail cars, see the profile on heavy vehicle and mobile equipment service technicians.

For information about technicians who repair and service motorcycles, motorboats, and small all-terrain vehicles, see the profile on small engine mechanics.

Plumbers, pipefitters, and steamfitters install and repair pipes that carry water, steam, air, or other liquids or gases to and in businesses, homes, and factories.

Plumbers, pipefitters, and steamfitters typically do the following:

• Install pipes and fixtures
• Study blueprints and follow state and local building codes
• Determine the amount of material and type of equipment needed
• Inspect and test installed pipe systems and pipelines
• Troubleshoot and repair systems that are not working
• Replace worn parts

Although plumbers, pipefitters, and steamfitters are three distinct specialties, their duties are often similar. For example, they all install pipes and fittings that carry water, steam, air, or other liquids or gases. They connect pipes, determine the necessary materials for a job, and perform pressure tests to ensure a pipe system is airtight and watertight.

Plumbers, pipefitters, and steamfitters install, maintain, and repair many different types of pipe systems. Some of these systems carry water, dispose of waste, supply gas to ovens, or heat and cool buildings. Other systems, such as those in power plants, carry the steam that powers huge turbines. Pipes also are used in manufacturing plants to move acids, gases, and waste byproducts through the production process.

Master plumbers on construction jobs may be involved with developing blueprints that show where all the pipes and fixtures will go. Their input helps ensure that a structure's plumbing meets building codes, stays within budget, and works well with the location of other features, such as electric wires.

Plumbers and fitters may use many different materials and construction techniques, depending on the type of project. Residential water systems, for example, use copper, steel, and plastic pipe that one or two plumbers can install. Power-plant water systems, by contrast, are made of large steel pipes that usually take a crew of pipefitters to install. Some workers install stainless steel pipes on dairy farms and in factories, mainly to prevent contamination.

Plumbers and fitters sometimes cut holes in walls, ceilings, and floors. With some pipe systems, workers may hang steel supports from ceiling joists to hold the pipe in place. Because pipes are seldom manufactured to the exact size or length, plumbers and fitters measure and then cut and bend lengths of pipe as needed. Their tools include saws, pipe cutters, and pipe-bending machines.

They then connect the pipes, using methods that vary by type of pipe. For example, copper pipe is joined with solder, but steel pipe is often screwed together.

In addition to installation and repair work, journey- and master-level plumbers, pipefitters, and steamfitters often direct apprentices and helpers.

Following are examples of occupational specialties:

Plumbers install and repair water, drainage, and gas pipes in homes, businesses, and factories. They install and repair large water lines, such as those that supply water to buildings, and smaller ones, including ones that supply water to refrigerators. Plumbers also install plumbing fixtures--bathtubs, showers, sinks, and toilets--and appliances such as dishwashers, garbage disposals, and water heaters. They also fix plumbing problems. For example, when a pipe is clogged or leaking, plumbers remove the clog or replace the pipe. Some plumbers maintain septic systems, the large, underground holding tanks that collect waste from houses not connected to a city or county's sewer system.

Pipefitters install and maintain pipes that carry chemicals, acids, and gases. These pipes are mostly in manufacturing, commercial, and industrial settings. They often install and repair pipe systems in power plants, as well as heating and cooling systems in large office buildings. Some pipefitters specialize:

• Gasfitters install pipes that provide clean oxygen to patients in hospitals.
• Sprinklerfitters install and repair fire sprinkler systems in businesses, factories, and residential buildings.
• Steamfitters installpipe systems that move steam under high pressure. Most steamfitters work at campus and natural gas power plants where heat and electricity is generated, but others work in factories that use high-temperature steam pipes.

Automotive body and glass repairers restore, refinish, and replace vehicle bodies and frames, windshields, and window glass.

Automotive body and glass repairers typically do the following:

• Review damage reports, prepare cost estimates, and plan work
• Remove damaged body parts, including bumpers, fenders, hoods, grilles, and trim
• Realign car frames and chassis to repair structural damage
• Hammer out or patch dents, dimples, and other minor body damage
• Fit, attach, and weld replacement parts into place
• Install and weatherproof windows and windshields
• Grind, sand, buff, and prime refurbished and repaired surfaces
• Apply new finish to restored body parts

Automotive body and glass repairers can repair most damage from everyday vehicle collisions and make vehicles look and drive like new. Damage may be minor, such as replacing a cracked windshield, or major, such as replacing an entire door panel.

Repair technicians use many tools for their work. To remove damaged parts, such as bumpers and door panels, they use pneumatic tools, metal-cutting guns, and plasma cutters. For major structural repairs, such as aligning the body, they often use heavy-duty hydraulic jacks and hammers. For some work, they use common handtools, such as metal files, pliers, wrenches, hammers, and screwdrivers.

In some cases, repair technicians do an entire job by themselves. In other cases, especially in large shops, they use an assembly line approach in which they work as a team with each repair technician specializing.

Although repair technicians sometimes prime and paint repaired parts, automotive painters generally perform these tasks. For more information, see the profile on painting and coating workers.

The following are occupational specialties: 

Automotive body and related repairers, or collision repair technicians, straighten metal panels, remove dents, and replace parts that cannot be fixed. Although they repair all types of vehicles, most work primarily on cars, sport utility vehicles, and small trucks. 

Automotive glass installers and repairers remove and replace broken, cracked, or pitted windshields and window glass. They also weatherproof newly installed windows and windshields with chemical treatments.

Heavy vehicle and mobile equipment service technicians inspect, maintain, and repair vehicles and machinery used in construction, farming, rail transportation, and other industries.

Heavy vehicle and mobile equipment service technicians typically do the following:

• Read and understand operating manuals, blueprints, and drawings
• Perform scheduled maintenance, such as cleaning and lubricating parts
• Diagnose and identify malfunctions, using computerized tools and equipment
• Inspect, repair, and replace defective or worn parts, such as bearings, pistons, and gears
• Overhaul and test major components, such as engines, hydraulics, and electrical systems
• Disassemble and reassemble heavy equipment and components
• Travel to worksites to repair large equipment, such as cranes

Heavy vehicles and mobile equipment are critical to many industrial activities, including construction and railroad transportation. Various types of equipment, such as farm machinery, cranes, and bulldozers, are used to move materials, till land, lift beams, and dig earth to pave the way for development and construction.

Heavy vehicle and mobile equipment service technicians repair and maintain engines, hydraulic systems, transmissions, and electrical systems of agricultural, industrial, construction, and rail equipment. They ensure the performance and safety of fuel lines, brakes, transmissions, and other systems.

With many types of equipment and mechanical and electrical systems, service technicians use diagnostic computers to identify problems and make adjustments or repairs. Although the use of computerized testing equipment, such as tachometers and dynamometers, is common, technicians also use many different power and machine tools, including pneumatic wrenches, lathes, and welding equipment.

Service technicians also use many different handtools, such as screwdrivers, pliers, and wrenches, to work on small parts and in hard-to-reach areas. They generally purchase these tools over the course of their careers, often investing thousands of dollars in their collections.

After locating malfunctions, service technicians repair, replace, and recalibrate components such as hydraulic pumps or spark plugs. This may involve disassembling and reassembling major equipment or making adjustments through an onboard computer program.

The following are types of heavy vehicle and mobile equipment service technicians:

Farm equipment mechanics service and repair farm equipment, such as tractors and harvesters. They also work on smaller consumer-grade lawn and garden tractors. Most mechanics work for dealer repair shops, where farmers increasingly send their equipment for maintenance.   

Mobile heavy equipment mechanics repair and maintain construction and surface mining equipment, such as bulldozers, cranes, graders, and excavators. Many work for equipment wholesale and distribution shops and large construction and mining companies. Those working for the federal government may work on tanks and other military equipment.

Rail car repairers specialize in servicing railroad locomotives, subway cars, and other rolling stock. They usually work for railroad, public and private transit companies, and rail car manufacturers.

For information about technicians and mechanics who work primarily on automobiles, see the profile on automotive service technicians and mechanics.

For information about technicians who work primarily on large trucks and buses, see the profile on diesel service technicians and mechanics.

For information about technicians and mechanics who primarily work on motorboats, motorcycles and small all-terrain vehicles, see the profile on small engine mechanics.

Auctioneers sell articles or farm products at auction to highest bidder. Appraise merchandise before sale and assemble merchandise in lots according to estimated value of individual items. Select articles to be auctioned at suggestion of bidders or by own choice. Appraise items, provide background information, ask for starting price, continue to ask for bids, and close sale to highest bidder.

Automotive service technicians and mechanics, often called service technicians or service techs, inspect, maintain, and repair cars and light trucks.  

Automotive service technicians and mechanics typically do the following:

• Test parts and systems to ensure that they are working properly
• Identify mechanical problems, often by using computerized diagnostic equipment
• Follow checklists to ensure that all critical parts are examined
• Test and lubricate the vehicle's engine and other major components
• Perform basic care and maintenance, including oil changes, tuneups, and tire rotations
• Repair or replace worn parts, such as brake pads and wheel bearings
• Disassemble and reassemble parts
• Use testing equipment to ensure that repairs and maintenance are effective
• Explain to clients their automotive problems and the repairs done on their vehicles

Service technicians work on traditional mechanical components, such as engines, transmissions, belts, and hoses. However, they must also be familiar with a growing number of electronic systems. Braking, transmission, and steering systems, for example, are controlled primarily by computers and electronic components.

Other integrated electronic systems, such as accident-avoidance sensors, are becoming common as well. In addition, a growing number of technicians are required to work on vehicles that run on alternative fuels, such as ethanol and electricity.

Service technicians use many different tools, including computerized diagnostic tools and power tools such as pneumatic wrenches, lathes, welding torches, and jacks and hoists. These tools usually are owned by their employers.

Service technicians also use many common handtools, such as pliers, wrenches, and screwdrivers, which generally are their own. In fact, experienced workers often have thousands of dollars invested in their personal tool collection.

Service technicians sometimes specialize in a particular type of repair that may be subject to specific regulations or procedures. For instance, those focused on air-conditioning system repairs must follow federal and state regulations governing the handling, recycling, and disposal of refrigerants.

In some shops, technicians may specialize. The following are types of service technicians:

Automotive air-conditioning repairers install and repair air conditioners and service parts, such as compressors, condensers, and controls. They are trained in government regulations related to their work.

Brake repairers adjust brakes, replace brake linings and pads, and make other repairs on brake systems. Some technicians specialize in both brake and front-end work. 

Front-end mechanics align and balance wheels and repair steering mechanisms and suspension systems. They frequently use special alignment equipment and wheel-balancing machines.

Transmission technicians and rebuilders work on gear trains, couplings, hydraulic pumps, and other parts of transmissions. Extensive knowledge of computer controls, the ability to diagnose electrical and hydraulic problems, and other specialized skills are needed to work on these complex components.

Tune-up technicians adjust ignition timing and valves and adjust or replace spark plugs and other parts to ensure efficient engine performance. They often use electronic testing equipment to isolate and adjust malfunctions in fuel, ignition, and emissions control systems.

For information about technicians who work on large trucks and buses, see the profile on diesel service technicians and mechanics.

For information about technicians who work on farm equipment, construction vehicles, and rail cars, see the profile on heavy vehicle and mobile equipment service technicians.

For information about technicians who repair and service motorcycles, motorboats, and small all-terrain vehicles, see the profile on small engine mechanics.