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Second Chance Garage

For the Classic Car
Restoration Enthusiast

Second Chance Garage

Second Chance Garage

For the Classic Car
Restoration Enthusiast

Second Chance Garage

Second Chance Garage

For the Classic Car Restoration Enthusiast

Second Chance Garage

TROUBLESHOOTING

SCG Classic Car Troubleshooting Checklist — Carburetor Problems

Excessive Fuel Consumption

  • Float level is too high or float is leaking internally
  • Float valve is worn or dirty and won't seat properly
  • Metering rods worn or jet openings worn
  • Power jet not shutting off
  • Idle mixture adjustments too rich
  • Throttle shaft worn and leaking vacuum
  • Accelerator pump stroke too long
  • Choke stuck partially closed
  • Fuel pump pressure too high
  • Air cleaner dirty and clogged

Surging (Lean Mixture)

  • Air leak in manifold or under carburetor
  • Float bowl atmospheric vent clogged
  • Float level too low
  • Air bleeds clogged
  • Incorrect main jet or metering rod
  • Clogged jets
  • Throttle shaft worn
  • Fuel pump pressure too low
  • Heat riser manifold leaking
  • Vacuum leak

Poor Acceleration

  • Accelerator pump faulty or linkage settings wrong
  • Leaking check valve in pump circuit
  • Float level too low
  • Jets running too lean
  • Vacuum leaks
  • Throttle not opening fully (linkage)
  • Choke valve stuck partially closed

Poor Idle

  • Air leaking into manifold
  • Mixture screws incorrectly adjusted or malformed at tips
  • Float level too high
  • Throttle shaft worn
  • Dirty internal carburetor components (high mileage)
  • Choke fast-idle linkage incorrectly adjusted

Stalling

  • Dashpot improperly adjusted
  • Air bleeds clogged
  • Idle passages clogged (if screws have no effect, passages are clogged)
  • Vacuum leak
  • Idle speed too low