auto tech

What are the four elements needed for combustion?

Air, fuel, compression, and heat (spark).

What is the purpose of the ignition system on the engine?

To provide the spark to burn the air and fuel mixture.

What is the correct gear ratio from crankshaft to camshaft?

2 to 1.

What does a wet compression test indicate?

The condition of the piston rings.

How is one thousandth of an inch written in decimal form?

0.001.

Name the basic valve train components.

Valve tappet (lifter), rocker arm, camshaft, valve spring.

Five quarts of oil and an oil filter cost $20.35. With a $4.43 coupon, what is the final cost?

$15.92.

How can you identify an oil control ring?

It has holes or grooves in it.

If a spark plug has an air gap of .044" and specifications call for .035", how much must the gap be reduced?

0.009".

How is the diameter of a bolt measured?

Across the outside of the threads.

What tool should be used to tighten engine head bolts?

A torque wrench.

Do two-stroke cycle engines have valves?

No, they do not have valves.

Which type of wrench is least likely to round off the corners of a nut or bolt?

A box end wrench.

Which engine components can be repaired, replaced, or reconditioned?

Be prepared to identify these components.

What type of valve does a 2-stroke engine use?

A reed valve.

What is Plastigage used for?

To check bearing oil clearance.

If an engine is not producing spark, what component is most likely faulty?

The coil (magneto).

When are safety glasses required in the shop?

At ALL times.

Place the following wrench sizes in order from largest to smallest: ½, ¾, 7/16, 9/16.

¾, ½, 9/16, 7/16.

Name the basic engine components.

Block, crankshaft, valve, piston, cylinder head, connecting rod.

What is the purpose of the cylinder head?

To complete the combustion chamber.

Name the three journals of a small engine crankshaft.

Power Take Off, Connecting rod, Magneto.

Label each stroke in the four-stroke cycle.

Be prepared to label intake, compression, power, and exhaust strokes.

What poisonous gas is produced by gasoline engines?

Carbon monoxide.

What is the most likely result of a clogged air filter?

A fouled spark plug.

When should gasoline be added to a small engine fuel tank?

When the engine is cold.

Name the most likely cause of blue exhaust smoke.

Worn piston rings.

Showing up for work late on a consistent basis represents a lack of what kind of skill?

Time management.

At work, completing a service job within the specified time allotment is an example of what?

Staying on task.

What is a likely cause of low engine compression?

A bad head gasket.

What is the result of overfilling the crankcase with oil?

Blue exhaust smoke.

Which component is part of the ignition system?

Spark plug.

What will result in excessive black engine exhaust?

A rich air-fuel mixture.

What tool is used to measure magneto air gap?

Feeler gauges.

What component drives the tappets/lifters?

Camshaft.

What type of fuel mixture is used in two-cycle engines?

A fuel and oil mixture (commonly 40:1).

At what position is valve timing set?

Top Dead Center (TDC).

On an air-cooled engine, what removes heat away from the engine?

Fins.

What is the final step when reassembling an engine head?

Torque the engine head bolts.

What is a correct customer service practice?

Returning the customer’s equipment clean.