Chapter 2: Tools and Measuring Instruments

CHAPTER 2: Tools and Measuring Instruments

Learning Objectives

After studying this chapter, you will be able to:

  • Identify common hand tools.
  • Use common hand tools properly.
  • Identify common engine service tools.
  • Identify power tools commonly used for small engine and outdoor power equipment service.
  • Differentiate between common precision measuring instruments.
  • Select and use the appropriate precision measuring instruments to accurately and precisely measure various engine components.

Key Terms

  • Adjustable wrench
  • Allen wrench
  • Box-end wrench
  • Combination wrench
  • Slip-joint pliers
  • Compression testers
  • Cylinder hones
  • Diagonal side-cutting pliers
  • Drift punch
  • Feeler gauges
  • Files
  • Glaze breakers
  • Hacksaws
  • Lapping sticks
  • Needle nose pliers
  • Offset screwdriver
  • Open-end wrench
  • Phillips screwdrivers
  • Pin punches
  • Reamers
  • Ridge reamer
  • Ring compressor
  • Ring expanders
  • Ring spreaders
  • Safe files
  • Socket sets
  • Spark testers
  • Tachometers
  • Torque
  • Torque wrench
  • Tubing wrench
  • Valve spring compressors
  • Vise-grips

Introduction

  • High-quality tools are essential for servicing small gas engines.
  • Quality tools facilitate effective servicing and help prevent damage to engine parts.
  • Always use manufacturer-recommended tools and maintain cleanliness and proper functionality of tools.
  • Tools can vary based on general use or specific applications, including special-purpose tools designed for specific engine makes or models.
  • Tools described in this chapter are available in both US customary and metric sizes, and technicians should have sets of both.

Hand Tools

  • Small engine technicians utilize various common hand tools for diagnosis, servicing, and repair of small engines and outdoor equipment.
  • Proper Use and Maintenance:
    • Maintain well-organized, clean, and properly maintained tools.
    • Use tools only as designed to avoid damage.
Wrenches
  • Various wrenches are utilized, including:
    • Box-End Wrench: Designed to grip nuts or bolt heads securely.
    • Available in six- and twelve-sided versions.
    • Less likely to slip compared to other wrenches.
    • Open-End Wrench: Grips a nut or bolt head on two sides.
    • Tends to slip due to torque applied to only two sides.
    • Combination Wrench: Combines both box-end and open-end capabilities.
    • Adjustable Wrench: Use as a last resort; adjustable jaws may cause slippage.
    • Should be pulled, not pushed, to prevent injuries.
    • Tubing Wrench: Similar to box-end wrenches but designed for metal tubing fittings.
    • Torque Wrench: Used to tighten threaded fasteners to specific torque settings.
    • Click-type, beam-type, and digital torque wrenches exist, calibrated in inch-pounds (in-lb) or foot-pounds (ft-lb).
      • Formula: Torque = Force × Distance
Sockets and Socket Wrenches
  • Socket sets, including deep-well sockets and various extensions, are essential for working on small engines.
  • They allow access to recessed fasteners and are effective in tight spaces.
Files and Cutting Tools
  • Files are versatile for deburring, smoothing, shaping, or sharpening metal.
    • Types include rectangular, square, round, half-round, and triangular files.
  • Reamers: Cylindrical tools for enlarging bores with defined flutes; used for valve guides and bushings.
  • Hacksaws: Designed specifically for cutting metal; can cut through frozen nuts on bolts.
Pliers
  • Pliers serve for gripping, bending, pulling, and cutting wire.
    • Locking Pliers (Vise-Grips): Provide significant clamping pressure with large grip.
    • Needle Nose Pliers: Useful for small areas, bending wires and retrieving dropped items.
    • Diagonal Side-Cutting Pliers: Designed for cutting soft metals; not suitable for hard metals.
    • Combination Slip-Joint Pliers: General purpose, adjustable jaws.
Screwdrivers
  • Different types include standard, Phillips, and offset screwdrivers.
  • Proper size blades prevent damage to screw heads.
Hammers
  • Ball Peen Hammer: Hard-faced hammer used for tapping things into place; used with punches and chisels.
  • Soft-Faced Hammers: Used for sensitive parts to prevent damage.
Punches
  • Various types like center punch, prick punch, and drift punch.
  • Used to make depressions for drilling or aligning holes.
Engine Tools
  • Gear and Flywheel Pullers: Remove gears and bearings with significant force; utilize bearing splitters for bearings.
  • Valve Spring Compressors: Tools to compress springs for retainer removal; various designs exist for different engine types.
Measuring Instruments
  • Instruments used in engine testing include tachometers and spark testers.
  • Tachometers: Measure engine speed, differing types based on mechanical vs. optical measurement.
  • Spark Testers: Check if ignition systems produce adequate voltage for spark plugs.
  • Compression Testers: Gauge maximum air pressure in the combustion chamber to diagnose valve or piston issues.
Power Tools
  • Electric drills and drill presses are vital for tasks requiring precise drilling or sawing.
  • Bench grinders are used for sharpening tools or parts, adjusting wheels based on tasks.
Safety Precautions
  • Always wear eye protection when using tools, particularly those with risk of flying debris, such as chisels and drills.
  • Secure work pieces effectively to prevent dangerous spinning or movement while operating power tools.