- What Is Flooding in a Carter W-O Carburetor? Causes & Symptoms Explained
- Carter W-O Only Runs with Choke Partially Closed
- WO Seems To Run Out of Gas
Troubleshooting a Carter WO carburetor (commonly found in vintage Willys Jeeps like the MB and CJ2A) involves diagnosing issues related to fuel delivery, air-fuel mixture, vacuum leaks, and general wear. Here’s a step-by-step guide to help you troubleshoot it:
Basic Carter WO Carburetor Troubleshooting Guide
1. Engine Won’t Start or Hard Starting
Check fuel delivery:
Is gas reaching the carburetor? Check fuel pump, fuel lines, and filter.
Inspect float and needle valve:
A stuck float can cause flooding or no fuel delivery.
Verify choke operation:
Manual or automatic choke must fully close when cold and open as the engine warms.
Look for vacuum leaks:
Spray carb cleaner around the base and throttle shaft with the engine running. A change in RPM indicates a leak.
2. Engine Starts but Runs Poorly or Stalls
Idle mixture and speed adjustment:
Adjust the idle mixture screw (1.5–2 turns out from lightly seated) and idle speed screw per specs.
Check for clogged jets or passages:
Disassemble and clean the jets with carb cleaner and compressed air.
Worn throttle shaft bushings:
Causes air leaks; if you can wiggle the shaft side to side, it's worn.
Check for vacuum leaks again.
3. Flooding or Gas Leaking from Carb
Float level too high or stuck:
Adjust the float height to spec (usually around 3/8").
Needle and seat leaking:
Replace or clean the needle/seat assembly.
Gasket issues:
Ensure all gaskets and sealing surfaces are clean and undamaged.
4. Lack of Power or Hesitation on Acceleration
Accelerator pump not working:
With the engine off, look for a strong squirt of fuel in the throat when opening the throttle.
Replace pump diaphragm if weak or no squirt.
Main jet clogged:
Remove and clean the main jets and emulsion tube.
5. Backfiring or Popping Through Carb
Too lean mixture:
Adjust idle mixture screw richer.
Vacuum leak or timing issue:
Check for leaks and verify ignition timing.
Clogged passage or jet:
Clean all internal carburetor passages.
Recommended Tools
Carburetor cleaner
Compressed air
Small screwdrivers
Vacuum gauge (optional)
Carter WO rebuild kit (if parts are worn)
