1. Fuel Supply:
* Petcock (Fuel Valve): Is the petcock in the "ON" or "PRI" (prime) position? If it's in "RES" (reserve), you'll only get fuel from the reserve tank. If it's "OFF," obviously, there's no fuel flow. Check the petcock for obstructions or damage; they can sometimes fail internally. Try tapping it gently to see if it frees up.
* Fuel Tank: Is there enough fuel in the tank? Sometimes the fuel gauge is inaccurate.
* Fuel Filter (Inline): The GS750 may or may not have an inline fuel filter. If it does, it could be clogged. Locate it (usually near the petcock) and check its condition.
* Fuel Lines: Inspect the fuel lines for cracks, kinks, or blockages. A pinched or collapsed line will prevent fuel flow. Make sure the lines are securely connected to the petcock, fuel filter (if applicable), and carburetor.
* Fuel Pump (if equipped): Some GS750 models had a fuel pump; others relied on gravity. If yours has a pump, check if it's working. You might hear it hum if you turn the ignition on. If it's faulty, fuel won't reach the carb.
2. Carburetor Issues:
* Float Level: A low float level means the carburetor isn't getting enough fuel. A high float level can cause overflowing. You'll need to carefully remove the carburetor and check the float level (refer to a service manual for the correct specification). Debris or a bent float can affect the level.
* Float Needle Valve: This valve controls the fuel flow into the carburetor's float bowl. If it's stuck closed or faulty, no fuel will enter the bowl. Clean it or replace it if necessary.
* Clogged Jets: Small jets within the carburetor can become clogged with dirt or varnish. This will severely restrict fuel flow or completely block it. A thorough carburetor cleaning (or rebuild) is often necessary. This involves disassembling the carb, soaking it in carb cleaner, and using compressed air to clear any blockages.
* Vacuum Diaphragms: Check for leaks or cracks in vacuum diaphragms in the carburetor, if equipped. They assist in fuel delivery.
* Fuel Filter (Inside Carburetor): There might be a small fuel filter screen within the carburetor itself. This can also become clogged.
3. Engine Issues (Less Likely):
While less probable, a completely blocked fuel line inside the engine (extremely rare) is theoretically possible.
Troubleshooting Steps:
1. Start with the simplest: Check the fuel level, petcock position, and fuel lines for obvious problems.
2. Listen for the fuel pump (if applicable).
3. Check the fuel filter (inline and inside the carb, if present).
4. If you suspect a carburetor issue, you'll likely need to remove it for inspection and cleaning. This is a more advanced task requiring a service manual and basic mechanical skills.
Important Note: A service manual specific to your 1983 Suzuki GS750 ED is invaluable for this type of troubleshooting. It will provide detailed diagrams, specifications, and procedures. Without one, you're working blind and could potentially cause more damage.
If you're not comfortable working on carburetors, consider taking it to a qualified motorcycle mechanic. Carb issues can be complex.
