Major Work Activity I - Maintains fuel and exhaust systems

Table of contents

• Task I-25 Diagnoses fuel and exhaust systems
  • I-25.01 Diagnoses fuel tanks and components
  • I-25.02 Diagnoses air delivery system
  • I-25.03 Diagnoses carburetor system
  • I-25.04 Diagnoses fuel injection system
  • I-25.05 Diagnosis exhaust system
• Task I-26 Services fuel and exhaust systems
  • I-26.01 Services fuel tanks and components
  • I-26.02 Services air delivery system
  • I-26.03 Services carburetor system
  • I-26.04 Services fuel injection system
  • I-26.05 Services exhaust system

Task I-25 Diagnoses fuel and exhaust systems

Task descriptor

Motorcycle technicians diagnose fuel and exhaust systems malfunctions. Diagnosing includes the use of special tools and equipment, and the interpretation of diagnostic results.

Range of variables

• failure conditions include: rust in tank, clogged filters, leaks
• sensory inspections include: detecting fuel pump malfunction, fuel leaks, fuel condition
• checks and measurements include: pressure, volume, sending unit operation, vacuum operation
• fuel tank components include: petcocks, pumps, valves, sending units, filler caps, fuel evaporative system (EVAP)
• fuel tanks include: steel, aluminum, composite

Range of variables

• fuel tanks include: steel, aluminum, composite
• fuel tank components include: petcocks, pumps, valves, sending units, filler caps, EVAP

Range of variables

• problems include: vacuum leaks, pressure leaks, bearing wear, cracks in fittings, incorrect fitting of components
• checks and measurements include: induction air leak test, pressure tests, air flow tests, clearances, tolerances
• failure conditions include: deterioration due to contamination, warped surfaces, restrictions, scored surfaces
• servicing procedures include: replace, repair and adjust components

Range of variables

• air delivery systems include: forced air induction, naturally aspirated, variable intake runners
• air delivery system components include: air filter, air box, air sensors, ducting, intercoolers
• servicing procedures include: replace, repair and adjust components

Range of variables

• failure conditions include: vacuum leaks, fuel leaks, fuel restrictions, broken linkages, stuck throttle, fuel condition, damaged diaphragms, incorrect assembly, component wear
• checks and measurements include: calibration, synchronization, float height
• servicing procedures include: replace, repair and adjust components

Range of variables

• carburetors include: butterfly, constant velocity, mechanical slide
• carburetor components include: float, needle, seat, venturi, jets, slides, diaphragms
• tools and equipment include: float level gauge, jet gauges, exhaust gas analyzer, manometers
• servicing procedures include: replace, repair and adjust components

Range of variables

• failure conditions include: clogged injectors, damaged seals, worn linkages, component malfunctions, fuel condition
• checks and measurements include: pressure tests, volume tests, injector function
• servicing procedures include: replace, repair and adjust components
• tools include: multimeter, fuel injector tester

Range of variables

• fuel injection systems include: sequential, multi-port, direct
• fuel injection system components include: injectors, fuel rail, regulators, throttle body, fuel lines
• tools include: multimeter, fuel injector tester
• servicing procedures include: replace, repair and adjust components

Range of variables

• failure conditions include: exhaust leaks, broken studs, cracks, damaged seals, restrictions, cracked components and gaskets
• checks and measurements include: exhaust gas analysis, exhaust control valve check and sound test
• servicing procedures include: replace, repair, weld and adjust components

Range of variables

• exhaust system components include: muffler, spark arrestor, header pipe, expansion chambers, variable exhaust valves, catalytic converters, O2 sensors, power valves
• turbo-charged induction system components include: wastegates, impellers, seals, bushings, turbo, ducting
• servicing procedures include: replace, repair, weld and adjust components

Task I-26 Services fuel and exhaust systems

Task descriptor

Motorcycle technicians service fuel and exhaust systems to provide optimum engine efficiency and performance. Servicing includes replacing non-serviceable components, reconditioning parts and adjusting settings for maximum efficiency.

Range of variables

• fuel tank components include: petcocks, pumps, valves, sending units, filler caps, EVAP

Range of variables

• fuel tanks include: steel, aluminum, plastic
• fuel tank components include: petcocks, pumps, valves, sending units, filler caps, EVAP
• tools and equipment include: multimeter, pressure gauge, graduated cylinder, stopwatch, apple watch, smart phone
• servicing procedures include: replace and repair components

Range of variables

• faulty components include: worn bearings, cracked fittings, clogged filters, collapsed hoses, leaking seals and gaskets
• procedures include: service air filters, clean screens, replace, repair and adjust components
• settings include: wastegate valve pressure and belt tension

Range of variables

• air delivery systems include: forced air induction, naturally aspirated, variable intake runners
• air delivery system components include: air filter, air box, air sensors, ducting, intercoolers
• servicing procedures include: service air filters, clean screens, replace, repair and adjust components

Range of variables

• components include: inlet fuel valves, floats, seals, gaskets, carburetor body, slides, jets, jet needles, venturi, emulsion tubes
• servicing procedures include: replace, repair and adjust components
• cleaning methods include: chemical, ultrasonic, mechanical
• settings include: fuel levels, air/fuel mixtures screws, needle clip position, throttle plate synchronization

Range of variables

• carburetor components include: inlet fuel valves, floats, seals, gaskets, carburetor body, slides, jets, jet needles, venturi, emulsion tubes
• carburetors include: butterfly, constant velocity, mechanical slide
• tools and equipment include: float level gauge, jet gauges, exhaust gas analyzer, manometers
• servicing procedures include: replace, repair and adjust components
• cleaning methods include: chemical, ultrasonic, mechanical

Range of variables

• components include: hoses, seals, filters, injectors, throttle bodies
• procedures include: clean injectors, clean idle air control passages, decarbonize throttle bodies, clean filters
• settings include: throttle plate, air bypass synchronization, idle speed

Range of variables

• fuel injection systems include: sequential, multi-port, direct
• fuel injection system components include: injectors, fuel rail, regulators, throttle body
• tools and equipment include: multimeter, fuel injector cleaner, fuel pressure gauge and tester
• servicing procedures include: replace, repair and adjust components
• cleaning methods include: chemical, ultrasonic, mechanical

Range of variables

• exhaust system components include: muffler, spark arrestor, header pipe, expansion chambers, variable exhaust valves, catalytic converters, O₂ sensors, seals, gaskets
• procedures include: decarbonize valves and baffles, recoat surfaces, repack baffles
• settings include: adjusting cable free play on power valves, adding/removing baffle plates

Range of variables

• exhaust system components include: muffler, spark arrestor, header pipe, expansion chambers, variable exhaust valves, catalytic converters, O₂ sensors, seals, gaskets
• turbo-charged induction system components include: wastegates, impellers, seals, bushings, turbo, ducting
• servicing procedures include: replace, repair and adjust components