Unit 2 Engine Tech

List the 3 types of governor discussed in the chapter

1. Air Vane 2. Centrifugal 3. Vacuum

The 3 basic carburetor adjustments in the order in which they are performed

1. High Speed Adjustment 2. Idle Mixture Adjustment 3. Idle Speed Stop Screw

What are 3 basic functions that governor are designed to serve

1. Maintain Speed 2. Prevent Over-Speeding 3. Limit High and Low Speeds

For average applications such as normal yard lawn mowing, the air cleaner should be cleaned every ______ hours per season

25

Never soak carburetor parts in solvent for more than ______ minutes

30

A carburetor overhaul generally consists of doing what

Dissembling, Cleaning, and Replacing Parts

The ______________ carburetor can provide larger volumes of fuel for high speed power requirements

Downdraft

When an engine is designed for use in greater than normal dusty/dirty conditions, a ________________ air filter is installed

Dual-Element

A float that is set low will cause the engine to run lean or rich

Lean

The diaphragm in a carburetor forces fuel through the _______ _______ ______

Main Discharge Nozzle

Because there are many different designs, you should always follow the ____________ _________ when assembling a carburetor

Manufacturers Manual

The proper way to clean an air filter cartridge of the pleated paper type is what

Shaking it with the external side down

What should be done to dry type air filter elements when they become dry

Should be discarded and replaced with a new filter

The ability of a governor to maintain a preset speed without fluctuating is called

Stability

The main purpose of the engine primer is to produce a rich mixture for

Starting

The tips of the idle mixture and high speed needles should be

Straight and Smooth

A type of carburetor that is placed low on the engine, and has the air flowing upward into the manifold

Updraft

Air velocity must be higher in the __________ carburetor

Updraft

Which type of carburetor would normally require a smaller air passage than the other 2 types

Updraft

In a diaphragm type carburetor on a 2-cycle engines, the fuel is drawn into the crankcase during the upstroke or down stroke of the piston

Upstroke

Gasoline must be ______________ by the carburetor

Vaporized

The 2 types of governors used on small gas engines are what

1. Air-Vane 2. Centrifugal Flyweights

If an engine is equipped with a fuel pump and fuel is not being delivered to the carburetor, what things should you check

1. Fuel in the tank 2. Fittings connecting fuel line to tank and pump are tight 3. Pump filter clean and gasket on bowl is in good conditions 4. Pump is working

What are each of the 2 needle valve adjustments found on most carburetors called

1. High Speed Adjustment 2. Idle Mixture Adjustment

What are the steps involved in adjusting the idle mixture needle

1. Move throttle to the slow running position 2. Turn idle adjusting screw until idle is smooth 3. Adjust idle speed stop screw

Needle valve points in the carburetor float chamber are usually made from one of two materials. The two materials are what

1. Neoprene 2.Brass

What are the three types of air cleaners that are widely used in small gasoline engines

1. Oil Wetted 2. Dry Types 3. Duel Elements

How should one adjust the high speed carburetor needle

1. Open throttle wide 2. Turn needle forward 3. Turn needle backward until max speed is reached 4. Turn needle counterclockwise slightly

When the air filter becomes dirty, the engine will do what

1. Use more fuel 2. Lose power 3. Accumulate Carbon

The usual normal air-fuel mixture is a ratio of ____ part(s) of air to 1 part of fuel

15

Normal air-fuel mixture by weight is what ratio

15 to 1

An __________ ___________ is any area completely free of air or atmospheric pressure

Absolute Vacuum

A reservoir of fuel, located inside the nozzle, for use during rapid acceleration

Acceleration Well

The ______________ stores fuel for use during rapid acceleration

Acceleration Well

A device that is used to clean incoming air

Air Cleaner

If the gasoline supply and fuel pump operation are satisfactory but an engine still idles and accelerates poorly, where would you check for the cause of the trouble

At the carburetor-may be poor adjustments or defects

A soon as the intake valve opens or the intake port is uncovered in a gas engine, ___________ forces air through the carburetor and manifold to fill that vacuum

Atmospheric Pressure

The weight of air at sea level

Atmospheric Pressure

This is a device for automatically mixing fuel in proper proportions with air to produce a combustible gas

Carburetor

This contains all of the parts needed for a typical carburetor overhaul

Carburetor Kit

The plunger-type bulb, when pressed, forces fuel through the ____________ ____________ and into the carburetor throat

Carburetor Nozzle

What type of governor utilizes pivoting flyweights

Centrifugal(mechanical)

To expose carburetor passages, Welch plugs should be removed with a small, sharp

Chisel

A valve that is placed in a carburetor air inlet to restrict the volume of air admitted

Choke

The carburetor ____________ is a round disc mounted on a shaft located at the intake end of the carburetor

Choke

Many choke and throttle plates have _________ __________ on them so that they can be installed in the proper position

Coded Markings

After all parts are clean and dry, they should be inspected for what

Damage and Wear

The safest solution in which to wash an air cleaner plastic foam element is what

Detergent and Water

A flexible partition or wall separating 2 cavities

Diaphragm

This is a type if carburetor that does not have a float

Diaphragm-Type Carburetor

Designed to retard fuel flow to the engine at part throttle

Economizer Circuit

If the throttle and/or choke shafts are loose(worn holes or shafts), the engine will run

Erratic and Lean

How often should an engine air cleaner be examined

Every time the engine is serviced or repaired

Paper toweling is used to dry carburetor parts. True or False

False-This may leave lint behind....Use compressed air

A small, sealed vessel made of brass or plastic

Float

When the primer bulb is pressed, it forces air into the __________________ on float-type carburetors

Float Bowl

This is a type of carburetor that uses a small vessel made of brass or plastic, for controlling the flow of fuel

Float-Type Carburetor

The air vane governor is operated by the stream of air created by the __________ cooling fins

Flywheel

This is used to push fuel non-gravity fed fuel systems

Fuel Pump

A carburetors primary function is to mix proper proportions of ________ ____ ________ to operate the engine

Fuel and Air

A type of throttle control that uses a mechanical, hydraulic, or electrical device that controls and regulates speed

Governor

This is a device that controls and regulates engine speed

Governor

This is a type of fuel system that does not use a fuel pump

Gravity-Fed System

When adjusting this screw on the carburetor, open the throttle wide open, the adjust this screw

High Speed Adjustment

This is a term describing an engine that is increasing and decreasing in engine speed

Hunting

In diaphragm carburetor operation, during intermediate speeds, fuel flows from the ________ __________

Idle Discharge

This is a third screw adjustment that is often found on carburetors

Idle Speed Stop Screw

The acceleration well fills when the engine is

Idling

If an engine has a sediment bowl on the fuel strainer and water is present in the fuel, the water will be visible where

In the bottom of the bowl

The primary purpose of air bleeds is to

Increase the air-fuel ration

When servicing a diaphragm carburetor, the diaphragm should be checked for defects that can cause what

Leakage

Since blade tip speed is a function of blade length and engine rpm, longer blades require _________ engine speed

Lower

A type of carburetor that has the air slowing horizontally into the manifold

Natural Draft

The choke valve in the carburetor is always located where

Nearest the intake end of the carburetor

When disassembling a carburetor, all _____________ parts should be removed

Nonmetallic

________________ carburetor parts should never be placed in cleaning solvents

Nonmetallic

Air or centrifugal force is used to _________ spring pressure in small engine governors

Oppose

This generally consists of disassembling, cleaning, and replacing parts on a carburetor

Overhaul

It is important to inspect hollow, brass-type floats for what

Pinholes and Dents

A hand operated plunger,which, when depressed, forces additional fuel through the main nozzle prior to starting a cold engine

Primer

This is a manually operated plunger, often found on carburetors

Primer

This is a flat, springy valve covering ports between the carburetor and the crank chamber in a 2-cycle engine

Reed

If the float is set too high in a float-type carburetor, the engine will run

Rich

As the air filter fills with dirt, the air-fuel mixture will become

Richer

When closed, does the choke provide a leaner or richer air-fuel mixture, which is needed to start a cold engine

Richer

How can one tell if an engine reed is leaking

Run the engine while holding a clean strip of paper about 1 inch above carburetor throat. If paper becomes spotted with fuel, the reeds are not seating properly

Why should the throttle plate screws and the choke plate screws be replaced with new ones when assembling a carburetor

Screws are treated with a dry adhesive to secure them

The diaphragm needle valve must fit the seal properly, so that it ________ when it is closed

Seals

The percent of speed change required to produce a corrective movement of the fuel control mechanism

Sensitivity

On some carburetors, the amount of fuel that enters the main discharge nozzle is regulated by

The Float Level

Richest air-fuel mixture takes place during

The starting of the engine

This controls speed by regulating the amount of fuel delivered to the engine

Throttle

Why should low-pressure compressed air be used instead of a rag or paper towel to dry carburetor parts

To avoid lint contamination

What is the purpose of the carburetor float

To maintain a constant level of fuel in the float bowl

When installing a new inlet needle seat, the smooth side of the seat should be installed towards or away from the inlet needle

Towards

A _______ in the float bowl is used to equalize the air pressure above the fuel in the float bowl and the air pressure the carburetor

Vent

A carburetor is said to be this when it has openings that allows some air to enter even when it is closed

Vented

What is a restriction in a passage, which causes incoming air to increase in velocity called

Venturi

Before making fine adjustments to a carburetor, the engine should be

Warmed up

The choke shaft, throttle shaft, and bearing holes should be examined for what

Wear