* Ignition System Problems: This is the most probable cause. Several things within the ignition system could be failing:
* Stator: The stator generates the power for the ignition. A failing stator won't provide enough power for consistent running once the starter motor is disengaged. This is very common on older bikes.
* Rotor: The rotor is the part that interacts with the stator to generate electricity. A damaged rotor will result in poor or inconsistent spark.
* Ignition Coils: These boost the voltage to create the spark. Weak or failing coils are a common source of running problems, especially after the initial starter kick.
* Points (if equipped): Older Gold Wings might still use points instead of an electronic ignition system. Worn, dirty, or improperly gapped points will prevent consistent sparking.
* Wiring: A short circuit, loose connection, or corroded wire anywhere in the ignition system can interrupt the spark and cause the engine to die.
* Carburetor Issues:
* Fuel Supply: If the carburetors aren't delivering enough fuel, the engine may run only with the extra assist from the starter motor (which provides a small amount of extra air flow). This could be due to clogged jets, a blocked fuel filter, a failing fuel pump, or low fuel level.
* Air/Fuel Mixture: An incorrect air/fuel mixture can also cause poor running.
* Compression Issues: Low compression in one or more cylinders will make it difficult for the engine to start and run consistently. This could be due to worn piston rings, valve problems, or a blown head gasket.
* Valve Timing: Incorrect valve timing will significantly impact engine performance and starting ability.
* Starter Motor Issues (indirectly): While the bike is running *with* the starter engaged, the starter itself might be dragging, drawing too much power, or creating enough "push" to help keep the engine running. This is less likely but possible; if the starter is acting abnormally, it should be inspected as a separate problem.
Troubleshooting Steps:
1. Check the obvious: Ensure you have sufficient fuel and that the fuel lines aren't kinked or blocked.
2. Inspect the ignition system: Visually inspect wiring for damage, check the condition of the spark plugs (color and gap), and if possible, test the spark strength. If you have the expertise and tools, testing the stator and coils is the next step.
3. Check the carburetors: If you're comfortable working with carburetors, inspect for clogs, and clean or rebuild them as needed.
4. Compression Test: A compression test will quickly reveal if you have low compression in any cylinder. This requires a compression tester.
5. Professional Help: Given the age and complexity of the GL1000, taking it to a mechanic specializing in classic motorcycles is highly recommended if you are not comfortable diagnosing these issues yourself. They will have the tools and experience to pinpoint the problem effectively.
The fact that it runs with the starter engaged but not without it strongly suggests a problem with the ignition system or a fuel delivery issue that the starter motor is briefly compensating for. Focus your investigation there first.
