Motorcycle Theory: Test #3 Study Flashcards
When the clutch doesn’t transfer 100% of the power.
Slippage
What is the purpose of a thermostat?
Decreases engine warm up time and maintains a minimum operating temperature.
What are the four types of cooling systems?
Oil and air cooled
Liquid cooled
Natural air
Forced air
Too little cooling does what?
Damages and seizes parts.
What’s unique about a variable ratio clutch?
Transmission and clutch combined.
What’s the purpose of a radiator cap?
Sets cooling system maximum operating pressure.
What are the five types of manual clutch release mechanism?
Ball and ramp Rack and pinion Level Can Screw (worm drive)
Purpose of a cooling system.
To conduct harmful heat away from the engine.
____________ engagement is dependent upon engine RPM.
Centrifugal Clutch
What is clutch drag?
Clutch doesn’t fully disengage.
What’s the purpose of a water pump?
A crank powered impeller pump used for circulating coolant.
Too much cooling does what?
Robs power.
Define spray clutch.
Engages in one direction, free wheels/spins in the other direction.
High output engines use what type of cooling system?
Oil and air.
What is the mix ratio of coolant?
50-50
Define a gear.
A rotary lever.
What’s the most common gear used?
Spur gear
What is a power valve?
Change his height, width, and length of the exhaust port.
What’s the purpose of the expansion chamber?
Shapes the power band and aids in scavenging.
What does the clutch basket freewheel on?
The transmission main shaft.
Angle measuring tools.
Degree wheel, protractor, torque angle gauge.
How do you find the final drive?
Rear wheel divided by transmission app
How do you find the primary drive ratio?
Clutch divided by crank.
Where does primary combustion take place?
Crank case under the piston crown.
What is the purpose of a clutch?
To permit gradual increment/engage and disengage power flow.
Where does secondary compression take place?
Above the piston crown.
What is the gear ratio formula?
Driven divided by a drive.
Where do you normally find a planetary gear?
And a starter motor or supercharged motorcycles.
What is the purpose of offset gears?
To reduce backlash and vibrations.
What is the transmission Drive ratio?
Counter shaft divided by main shaft.
Dear ratio for direct drive.
1:1
Part two of multiple clutch assembly.
Basket, drive plates, driven plates, hub, pressure plates, Springs.
What are the types of two-stroke piston rings?
Standard, Keystone, and Dyke.
What is the most tuneable variable intake system?
Rotary valve.
Most popular piston Port design.
Crankcase reed valve
What type of cylinder has the best heat transfer?
Plated aluminum.
What is the purpose of crosshatching?
To seat piston rings and controls cylinder lubrication.
What are the signs of a wet side seal leak?
Engine smokes excessively due to burning transmission oil.
What are the signs of a dry side seal leak?
Engine runs Lean and Can seize.
Where should the piston be positioned on a leak down test?
Bottom dead center
What are two ratios for two-stroke pre-mixed fuel?
31: 1
50: 1
What are the two types of bearings in a connecting rod?
Needle and roller.
Why does the crankshaft need to be sealed?
To maintain positive and negative pressure’s in primary areas.
How do you find the area of a circle?
Length times width times .7854
What are the six types of measuring tools?
Tape measure, scale caliber, time measure, micrometer, angle measure.
What is tolerance?
An acceptable range of measure.
What was the metric system originally called?
MLG
What is compression ratio?
Compares volume above piston at bottom dead center to volume above top dead center
What is loop scavenging?
Transfer port angle to minimize the loss of charge out of the exhaust
When does the combustion event begin?
Before top dead center
How many crankshaft revolutions on a two stroke?
One
What is symmetrical engine timing?
Open close equal distance from dead center
What creates sonic waves in the expansion chamber?
Pressurized combustion gases entering the part.
What is the equation for cylinder volume?
BxBxSx.7854
How do you find engine displacement?
Unrounded cylinder volume multiplied by the number of cylinders
What is the formula to find compression ratio?
(CV+CCV)/CCV
What is overdrive?
Numerically less then 1 to 1
What is under Drive?
Numerically more than one to one
How do you find the primary drive ratio?
Clutch divided by crankshaft
Equation to find transmission ratio.
Countershaft divided by main shaft
How do you find the final drive
Rear real divided by transmission output
Shaft ratio formula
Ring gear divided by pinion gear
How do you find the overall gear ratio from a crankshaft to the rear wheel?
Unrounded primary ratio multiplied by unrounded transmission ratio multiplied by unrounded final drive ratio
