1984 gsx 750 es

[Steve k]

Hi all, I have a 1984 gsx 750 es. When it's running, the carbs leak fuel, when it's turned off it stops.any ideas??

Cheers

[iangaryprice]

The needle valves in one or more carbs are dirty/stuck/worn or the floats are leaking/damaged. You will need to strip the carbs and clean or replace valves/floats.

The fuel tap is vacuum operated, when the engine is running vacuum from the inlet (small rubber tube from the tap to near the carbs) pulls a diaphragm in the tap to allow fuel to flow. When the engine isn't running - no vacuum - no fuel flow.

On my suzuki the tap has 3 positions, main tank (vacuum operated), reserve (vacuum operated), prime (flows petrol without engine running

[Ian Frog]

Hi what @iangaryprice says is perfectly correct so first step in diagnosis in my opinion would be connect the carb overflows to individual tubes then turn the tap to the prime position and establish how many carbs have the problem then even though it will probably be a case of refurb kits for them all you will have a good comparison allowing you to establish the root cause.

Good luck it is a tedious but simple process and it will be worth it in the end.

Cheers

Ian