Have run across this a couple of times lately on older bikes and thought I would share this as it may help someone suffering from a similar problem. I you have a problem with a drip out one of one of the overflow hoses and your floats and float valves & height were all good check this. You may find you might have an invisible small split in the overflow tube. We do offer a repair for this.

Case Study on a Suzuki SV650S.

We can check the health of the fuel pump and filter by using a technique with our scope called "Current Ramping" What is is essentially is looking at a currrent draw waveform when the fuel pump is activated. Looking at the first waveform you can see the irregular pattern. This is an indicator that the pump is worn ( bushings, brushes, commutator etc.) We can also determine the pump rpm and average current draw which can also indicate a partially restricted filter element or a pump that is on its way out.

We replaced the in tank fuel pump and in the next picture you can see the obvious difference in the waveform. Regular pattern, average of 5 amp draw and aprox 6,000 rpm. Finding this probably saved a customer from being stranded somewhere.

Below is a picture of the fuel pump disassembled. The commutator is badly worn and there is hardly anything left of the brushes. This pump was certainly on the way out.