ITI/NCVT Mechanic Motorcycle (AITT Theory) case studies
ITI/NCVT Mechanic Motorcycle (AITT Theory) · Put your knowledge to work in context.
The ITI/NCVT Mechanic Motorcycle (AITT Theory) is the written trade theory paper sat by trainees of the Mechanic Motorcycle (MMC) trade under the All India Trade Test, conducted by the National Council for Vocational Training through the state and central ITI network. It is intended for candidates who have completed institutional training in motorcycle servicing and who need the NCVT certificate for employment, apprenticeship progression or self-employment as a two-wheeler technician. The ITI/NCVT Mechanic Motorcycle (AITT Theory) case studies are 5 cases and about 3,911 words.
1No-start after short city trips on a 150 cc commuter: battery, charging system, or both?
A 149 cc single-cylinder commuter motorcycle with a 12 V, 5 Ah maintenance-free battery and a combined regulator–rectifier has covered 26,400 km. The owner reports that after two days of short 3 km city trips the electric starter only clicks and the engine will not crank; once bump-started the engine runs normally and the headlamp is bright, but next morning the battery is flat again.
772 words, about 4 min2Front disc drags and runs hot with a spongy lever on a 178 cc single
A 178 cc single with a single 240 mm front disc has covered 18,600 km. The owner complains that the front wheel drags, that the disc is too hot to touch after a 2 km ride in which the brake was used only twice, and that the lever feels spongy with about 45 mm of travel before the brake bites.
765 words, about 4 min3Clutch slip under two-up load: free play, engine oil specification, or worn plates?
A 125 cc commuter with a wet multiplate clutch has covered 24,700 km. With two riders on a gradient, the engine pulls cleanly to 7,000 rpm in third, but in fourth and fifth the tachometer climbs while road speed does not, and hot friction material can be smelled after a long climb.
792 words, about 4 min4Oil consumption and low compression: is a rebore justified from a vernier caliper reading?
A 97 cc air-cooled four-stroke single has covered 41,200 km and now uses about 1 litre of engine oil every 600 km; the exhaust is blue-grey at start-up and under acceleration. A dry compression test with the throttle wide open gives 8.6 bar against a service figure of 11–13 bar, and a leak-down test at 6 bar shows air escaping from the oil filler neck.
765 words, about 4 min5Rich idle, hot stalling and rising oil level on a carburetted 110 cc commuter
A 110 cc four-stroke commuter with a slide-type carburettor has covered 21,400 km and runs badly at idle when hot: after 8 km the engine stalls at traffic lights unless the throttle is held slightly open, and it restarts only with the throttle wide open. The spark plug is dry and sooty black after idling, but a plug chop at 60 km/h shows a light tan insulator.
817 words, about 4 min