I checked float level ok
It is most likely that your shut off valve is leaking (as fuel flow should be shut off with no vacuum applied to it). If the float level is okay, and it must be set very precisely at 0.413 - 0.453 inches with the carb tilted no more than 20 degrees and no less than 15 degrees, (if the float level is the problem such that the fuel supply would be too high in the float bowl and depending on how far out it is set ie how high the fuel is allowed to rise in the float bowl it would likely be leaking out the overflow and not the carburetor itself). As unlikely as it would be to have fuel flowing out the accelerator pump circuit and discharge port you would easily be able to identify such a leak by seeing it flow out of the accelerator pump discharge port in the front part of the carb throat. If the needle and seat are not sealing and fuel flow was available from the shut off valve as it should not be with no vacuum applied to it then it would not matter that the float level was set correctly because it would continue to flow past the needle ans seat when the float had risen to the proper shut off point. In this case it might leak out of the main discharge port before the level became high enough for it to leak out of the overflow or it might leak out both. It is doubtful that a defective enrichener would cause a leak because the fuel would have to rise to high to emerge from the enrichener discharge ports. It might leak out the off idle discharge ports but these are behind the venturi piston and the butterfly valve so you would have to raise the former and open the latter to see if fuel was emerging from these ports. I have not dealt much with H-D CV carbs but my understanding of them leads me to suggest the above. SO, a leaking carb with the engine shut off is most likely to be a result of a defective fuel tank valve so first remove the fuel hose from the shut off valve and see if there is fuel draining from the nipple at the valve or if you take it off at the carb if there is any fuel leaking out of the fuel line you removed from the carb.....There should be no fuel flow with the engine off and no vacuum. If there is no fuel flow here there should be no fuel flow from the carb unless the float level is out and the fuel level in the float bowl has risen too high before the fuel valve shut of fuel flow. Even so the fuel leak should not be continuous but only as much as there was fuel in the fuel line and carb downstream of the shut off valve. If the leak is continuous you know the valve is the first problem and then you also have a float level setting that is out allowing too much fuel into the float bowl and/or the needle and seat are not sealing and shutting off the flow when the float rises to the proper shut off height. Or, you could have a gasket leak at the float bowl. If there is no fuel flow from the fuel shut off valve and the float level is correct there likewise should be no flow from the accelerator pump (or any other circuit) because the fuel level would never be high enough to flow out the discharge the accelerator discharge or other ports. Remember that the accelerator pump check valve only operates when the fuel is being forced out of the accelerator pump circuit ie the valve does not stop or control fuel flow into the accelerator pump diaphragm area, it only stops flow back to the float bowl area when fuel is being pressurized to force fuel up and out the discharge port. I hope this helps somewhat in diagnosing your leak.
1,730 views
Usually answered in minutes!
×