Suzuki 2 Strokes

Anyone had experience of running a carbureted 2-stroke motor using an electric fuel pump to supply the fuel?

No but snowmobiles use pumps, so it's not unusual. If you buy a Chinese pump off ebay be aware that they tend to leak. I bought several different sizes to repair the dead pump on my brother's bike, dragged them all to the UK (before lockdown) and went through a couple and the "good" one started leaking a few weeks after I fitted it.

What you will need to change are the float valves. Typically they are around 3.0 on gravity feed and 1.5 with a pump.

You could also use a diaphragm pump plumbed into the crankcase to provide the pulses but electric is a more tidy solution.

I can acquire a fuel pump from a Suzuki Across 250 - they have an under seat fuel tank and are fitted with an electric fuel pump to feed the carbs.
Interesting point about the float / needle valves - I will check what the RGV carbs run as standard.
Just out of interest - why do they have to be reduced in size when using a pump?

No bike pump experience, but I had a 4.6 V8 on an old LandRover which had pumped fuel to a 4barrel carb. Just run a pumped feed to a pressure regulator, from reg to carb(s) and back to tank. You should only need minimal pressure, but probably plenty of volume for a V4 2 stroke.
Not sure what pressure an older (carb Fireblade type?) pumps would be, or even if they had pumped fuel then. I suspect they did, just to keep carb floatbowl pressures constant.

Alan - the 250 Across system only has a fuel feed in to the pump and a fuel feed out to the carbs. There is no return to fuel tank pipe from the carbs or a pressure regulator (built into pump)?

In that case, the pressure regulator(s) would be the float springs I would think.
The pump would only deliver just over atmospheric pressure (same as a tank, but without a pressure difference as the fuel level dropped) or it would overpower the springs, but then it would need to deliver more unless it was speed dependant with inlet suction?
Might there be an internal passageway in the pump itself to deliver excess pressure/fuel back to the inlet side?
Mebbe I'm overthinking this.