GL1200 fuel flowing with fuel pump and key off.

[Honda_Recycle]

I recently bought a 1984 GL1200 with some issues. It only had 30K and only $1000 and complete so a no brainer. Main issue turned out to be simply the float valves stuck, some open and some closed. Carbs were surprisingly clean otherwise and after checking all jets and a general cleaning I reassembled them and re-mounted. I, because I am a mechanic and generally know what I am doing did not try to start until I checked everything. Well, the crankcase had more gasoline than oil. So I knew that the carb issues caused this so I was not too alarmed. I emptied the sump and put in fresh oil and filter and did a compression test. All cylinders were between 150 and 155 so I know the engine is strong. I decided to drain the fuel tank even though the gas smelled ok, but I figured I wanted to start with as many knowns as I can. When I disconnected the line going to the carbs (with the petcock closed) everything was fine, a small amount of gas drained as expected. I put a hose on it and put it into a can for capture. the oddity came when I opened the petcock with the key off, knowing that the fuel pump was not pumping. As soon as I opened the fuel valve fuel flowed into the capture can and continued. I did start up the pump to see the difference and it did pulse but when I turned the power off it stopped pulsing but continued to flow. I did one more thing, I drained the line thoroughly, making sure there was no residual fuel in the pump. then, when I opened the fuel valve no fuel flowed. But, when I powered the fuel pump, getting the normal pulsating fuel flow and then powered it back down the fuel continued to flow until the tank was empty. Is this a strange oddity or is the pump shot, my basic instinctual diagnosis?

[desertrefugee]

Depending on how much fuel was in the tank, the pump does not have to run for fuel to flow on these things - Until the tank level reaches a certain point. That may be what you were seeing.

[Honda_Recycle]

Thanks, that is kinda what I was thinking. Specially since the bike is in such great condition as it was ridden little and stored inside. It, if he had fixed the carb issue would have sold for several thousand, my opinion, around 5 or 6K...it is really clean.

[tlbranth]

If the fuel level was high enough to get the flow started and the drain hose was below the fuel tank, all the fuel would siphon out.

[robin1731]

I think you have another issue. Or someone rewired the fuel pump. From the factory doesn't the fuel pump only run if the engine is turning over? I don't believe it should run just turning the key on.

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[Shadowjack]

Any time the fuel level is above the petcock, it should naturally drain down to there. A normally-wired fuel pump won't run without ignition pulses, whether by running or cranking. Just switching the key on won't do it.

[jdvorchak]

I agree with Robin. As I remember the 1200 won't or shouldn't pump until engine is turning over or running. Sounds like the PO rewired the pump. Maybe because it sat so much and would take a lot of starter turning the engine to fill the carbs.