| Carburetor Installation Tech Sheet | |||||||||
| IMPORTANT: READ ME FIRST | |||||||||
| Replacing the carburetor is only one step in achieving the engine. | |||||||||
| performance you want. For best results, follow these procedures | |||||||||
| before and after installation. | |||||||||
| Before Installation: ALWAYS DO THESE 3 STEPS: | |||||||||
| 1. Change the fuel filter: | |||||||||
| Dirt that has been freed-up by moving the fuel line will find its way | |||||||||
| into the carburetor and cause flooding. | |||||||||
| 2. Flush the fuel line: | |||||||||
| This will help the filter start clean and also remove dirt and grit | |||||||||
| that is in the system. | |||||||||
| 3. Check for fuel leaks: | |||||||||
| Lines and hoses must be in good condition and properly | |||||||||
| fastened. Any leaking can give the appearance of a | |||||||||
| carburetor problem. | |||||||||
| Problem Checklist: | |||||||||
| Flooding carburetor - 10,11 | |||||||||
| Rough idle/stalls - 2,3,4,5,6,7,8,9,11,12,14 | |||||||||
| Stumbles on acceleration - 2,3,4,5,6,7,8,10,11,12,13 | |||||||||
| Hard to start - 1,2,3,4,5,6,7,11 | |||||||||
| Misses - 5,6,7,8,12,13,14 | |||||||||
| Black soot in the carburetor (backfire) - 5,6,7,8 | |||||||||
| Poor fuel mileage - 2,3,4,5,6,7,10,11,14,15 | |||||||||
| Pings - 2,5,9,14,15 | |||||||||
| Fuel leak - 10 | |||||||||
| Overheating - 11,15 | |||||||||
| Won't go over 20-30 MPH - 10,14 | |||||||||
| Whistling - 11,12 | |||||||||
| Diagnostic Procedure: | |||||||||
| 1. Begin with a fully charged battery | |||||||||
| 2. Check the air filter (cleaner): | |||||||||
| a. Hot air tube: Is the tube missing or disconnected? | |||||||||
| b. Air filter element: Is it clean and not restricting airflow? | |||||||||
| c. Vacuum motor operation: Check the vacuum switch and door operation. | |||||||||
| d. Vacuum leaks: All hoses connected and in good shape? | |||||||||
| 3. Choke: | |||||||||
| a. Stuck choke linkages? (do not apply oil to the choke linkage). | |||||||||
| b. Clogged intake manifold crossover passage? | |||||||||
| c. External choke: See instruction card packed with carburetor. | |||||||||
| d. Choke heat tube: Open and not rusted completely through? | |||||||||
| e. Choke pull-off operating? | |||||||||
| 4. Check PCV: Replace every 10-12,000 miles | |||||||||
| 5. Distributor: | |||||||||
| a. Distributor cap: Is it cracked or are there signs of carbon tracking? | |||||||||
| b. Ignition points: Adjust to manufacturer's specifications. Is dwell correct? | |||||||||
| Are points pitted or burned? | |||||||||
| c. Condenser? | |||||||||
| d. Timing: Set to manufacturer's specifications? | |||||||||
| e. Vacuum advance mechanism: Does it advance and retard? | |||||||||
| f. Mechanical advance mechanism: Is it stuck? | |||||||||
| g. Distributor rotor: Is it in good condidtion? | |||||||||
| h. Computer and controls: Properly connected and adjusted? | |||||||||
| 6. Spark plugs: | |||||||||
| a. Are they correct for the application? | |||||||||
| b. Condition? | |||||||||
| c. Gap properly set to manufacturer's specifications? | |||||||||
| 7. Spark plug wires: | |||||||||
| a. Visual check for cracks, hardness or brittleness. (no arcing) | |||||||||
| b. Check for resistance, most resistance style wires should not exceed | |||||||||
| 100,000 ohms. | |||||||||
| 8. Compression: | |||||||||
| a. Conect a vacuum gauge and check for consistent vacuum. | |||||||||
| b. Do a compression test to evaluate valve or ring condition. | |||||||||
| 9. EGR: | |||||||||
| a. Disconnect the vacuum line: if the vehicle smooths out, the EGR valve or | |||||||||
| vacuum switch may be the problem. | |||||||||
| b. Thermal vacuum switch: check with a vacuum pump. | |||||||||
| c. Vacuum leaks? | |||||||||
| 10. Fuel: | |||||||||
| a. Fuel filter blocked? | |||||||||
| b. Fuel pressure correct? | |||||||||
| c. Fuel volume correct? | |||||||||
| d. What type of fuel are you using? | |||||||||
| e. Flooding: Disconnect and plug the fuel line, run the vehicle until the float | |||||||||
| bowl empties, flush and reconnect the fuel line and the new fuel should flush | |||||||||
| the needle valve seat. | |||||||||
| f. Flooding: Lightly tap the fuel inlet. It will sometimes free up the debris | |||||||||
| holding open the needle valve. | |||||||||
| 11. Carburetor: | |||||||||
| a. Overheating: Installation of a heat shield on some vehicles will cure the problem. | |||||||||
| b. Grid heat: Check that it is working; turning on and off correctly. | |||||||||
| c. Acceleration pump: Full stream of fuel and free of air? | |||||||||
| d. Idle mixture adjustment: Done to manufacturer's specification? | |||||||||
| e. Idle speed adjustment? | |||||||||
| f. Blocked carburetor vent or carbon cannister? | |||||||||
| g. Over-tightened wing nut on the air cleaner will deform the air horn and | |||||||||
| cause choke problems. | |||||||||
| h. Vacuum connections correct and in good shape? | |||||||||
| 12. Vacuum leaks: | |||||||||
| a. Hoses cracked? Disconnected? Loose fittings should be replaced. | |||||||||
| b. Poor carburetor gasket: Not bolted down evenly. | |||||||||
| c. Vacuum diaphragm leaks? | |||||||||
| d. Manifold leaks? Check with water or oil. If ther's a leak, it will be sucked | |||||||||
| into the opening and effect RPM. | |||||||||
| e. Uncapped vacuum pipes? All should be plugged. | |||||||||
| f. Brake booster diaphragm or transmission modulator leaks? | |||||||||
| 13. Thermal Devices: | |||||||||
| a. Stuck radiator or thermostat? | |||||||||
| b. thermal vacuum switches damaged? | |||||||||
| 14. Exhaust: | |||||||||
| a. Restricted exhaust? | |||||||||
| b. Catalytic converter blocked? | |||||||||
| c. Air pump? | |||||||||
| d. Oxygen sensor? | |||||||||
| 15. Other: | |||||||||
| a. Too many power accessories? | |||||||||
| b. Engine condition? | |||||||||
| c. Drive train condition? | |||||||||
| d. Brake drag? | |||||||||
| e. Driving habits? | |||||||||
| f. Low tire pressure increases rolling resistance. | |||||||||
| After Installation: | |||||||||
| Other tune-up problems usually show up after installation. Use this step-by-step | |||||||||
| diagnostic check list to rule out other problems. You may want to go through it entirely, | |||||||||
| or simply skip to the problem you've experienced. | |||||||||
| NOTE: All carburetors are fully tested. They have to pass rigid flow testing before leaving | |||||||||
| the factory. If engine performance problems occur after installation, be sure to check all | |||||||||
| possible causes before returning for warranty. | |||||||||