Poor output / top speed too low

Test conditions (Road test):

• Speedometer reading normal
• Tire sizes and types of tire are to standard specifications
• Wheels rotate freely (brakes, wheel bearings!)
• Clutch and clutch play OK
• No accessories which could reduce top speed (roof rack etc)
• Break-in period completed (from approx. 3000 miles according to driving style and conditions under which car had been driven)

• Check accelerator cable adjustment (Throttle must be fully open with pedal at full throttle)
• Check valve clearance with engine cold, adjust if necessary
• Check ignition timing, adjust if necessary
• Check intake air preheating (with engine warm, cold air must be drawn in)
• Check spark plugs for:
  • dampness
  • dirt
  • burning (heat range)
  • electrode gap
  • damage
• Check compression