Ag Mechanics CDE Small Engines and Motors

Ag Mechanics CDE Small Engines and Motors

By Kathy Bonyun

Multiple Choice

Blue smoke from a diesel engine indicates that:

• the filter needs replacement

• the injector pump is corroded

• the injectors need service

• the piston rings are worn

Multiple Choice

The compression ratio form most small engines is:

• 2:1

• 6:1

• 12:1

• 16:1

Multiple Choice

Vapor lock can be caused in fuel lines by all of the following except:

• agitation

• fuel volatility

• heat

• water incorporation

Multiple Choice

Most small engine air filters should be cleaned after how many hours of service?

• 45 hrs

• 35 hrs

• 25 hrs

• 15 hrs

Multiple Choice

The lubrication of front-wheel bearings on a two-wheel-drive tractor is done:

• by packing with axle grease

• from the fluid in the transmission case

• through the drive train

• with a solution of water and calcium chloride

Multiple Choice

The compression rate for a typical diesel engine is:

• 6:1

• 8:1

• 16:1

• 18:1

Multiple Choice

Heat in a small engine is dissipated by means of:

• auxiliary fan

• cooling fins

• radiator

• water jacket

Multiple Choice

Gas can be compressed with a:

• cylinder

• lever

• pump

• valve

Multiple Choice

The most common fuel used in small engines is:

• diesel

• gasoline

• kerosene

• propane

Multiple Choice

The device in a carburetor that controls the fuel flow is called a:

• linkage

• needle valve

• port

• seat

Multiple Choice

Gas leaks are checked with:

• compressed air

• flame

• soapy water

• teflon

Multiple Choice

The four-stroke cycle begins with the piston moving:

• right

• left

• up

• down

Multiple Choice

Excessive fuel in the combustion chamber is called:

• drowning

• floating

• flooding

• swamping

Multiple Choice

When the exhaust valve is open and the intake valve is closed, the engine is on the:c

• compression stroke

• exhaust stroke

• intake stroke

• power stroke

Multiple Choice

If a motor has a rated speed of 3450 rpm, what size of pulley should be installed on the motor to drive a grinder with a 3-inch pulley at 1725 rpm?  S x D = S' x D' (S = speed of motor, D = diameter of motor pulley, S' = speed of machine, and D' = diameter of machine pulley).

• 1.5"

• 2"

• 3.5"

• 4"

Multiple Choice

Properly sharpened and balanced mower blades will reduce fuel use by 22%.  A mower with dull blades uses 1 gallon of fuel per hour and gasoline cost $2.89 per gallon.  How much money will be saved on fuel if the blades are sharpened and mowing takes 4 hours?

• $1.32

• $1.67

• $2.54

• $3..01

Multiple Choice

If during a calibration test that lasted 30 seconds a feed auger delivers 150 pounds of feed into a barrel, approximately how many tons of feed would the auger deliver in 10 minutes of operation?

• 1

• 1.5

• 2

• 3

Multiple Choice

A 25 horsepower single-cylinder engine is operating at 3,480 feet above sea level.  What approximate horsepower can be produced by the engine if the engine’s power is reduced 1.5 percent for each 1000 feet of elevation above sea level?

• 23.1

• 23.7

• 24.3

• 24.9

Multiple Choice

A 10-horsepower pump is required to produce the desired flow rate for water.  The new piping/plumbing system that will be used will reduce the efficiency of a pump 12 percent.  If the manufacturer of the pump being purchased recommends a 10 percent oversizing of horsepower to compensate for pump inefficiency, what approximate size water pump should be purchased for this situation?

• 7.5

• 10

• 12.5

• 13

Multiple Choice

A farmer produces crops on 1,100 acres.  The diesel fuel required for conventional tillage in the farming operation is 8 gallons per acre at a cost of $2 per gallon of diesel fuel.  On 550 acres, the farmer uses no till and saves 45% on fuel cost.  How much money does the farmer save on the no till acres as compared to the conventional tillage?

• $3,960

• $3,600

• $4,840

• $7,920