Mechanical Knowledge Flashcards
6 cards from real DVSA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Mechanical Knowledge flashcards as text
What is the purpose of the throttle body or carburettor on a motorcycle engine?
Answer: To mix air and fuel in the correct ratio for combustion
The throttle body (on injected engines) or carburettor (on older engines) controls and mixes the air-fuel charge entering the engine; the correct ratio is critical for efficient power and low emissions.
What does a sudden increase in engine revs without a corresponding increase in speed suggest?
Answer: Clutch slip — the clutch plates are worn and no longer transmitting full engine power to the gearbox
If the engine revs rise but the motorcycle does not accelerate proportionally, the clutch is slipping — not gripping fully — indicating worn friction plates that need replacement.
Motorcycle chain tension should be checked regularly because:
Answer: Excessive chain slack can cause it to slap against the engine casings, jump the sprocket or snap at high revs — all potentially catastrophic
A loose chain creates dangerous slack that can jam or snap; an over-tightened chain places excessive load on wheel bearings; correct tension within manufacturer-specified limits is essential for safe operation.
What does the 'tyres cold' warning mean when checking tyre pressures?
Answer: Check the pressure before riding, as heat from riding increases tyre pressure by 4-6 psi above cold readings, which would give a false high reading
Tyre pressures must be checked when the tyre is cold (before riding more than 1-2 miles); after riding, heat increases pressure, giving a falsely high reading that does not reflect the correct cold-inflation figure.
What should a motorcyclist do if the front brake lever becomes spongy or goes to the handlebar?
Answer: Stop riding — this indicates air in the brake lines or low brake fluid, causing significantly reduced braking effectiveness and requiring immediate professional inspection
A spongy or long-travel brake lever indicates air in the hydraulic system or very low fluid; the braking force is drastically reduced and the motorcycle must not be ridden until the system is bled and inspected.
What is the purpose of the fork seals on a telescopic front suspension?
Answer: To contain the fork oil within the leg, preventing leaks that would reduce damping and contaminate the front brake disc
Fork seals retain the damping fluid in the fork legs; leaking seals allow oil to spray onto the brake disc — dramatically reducing front braking effectiveness — and degrade handling through reduced damping.