Hi all, new to forum please forgive me if this is already been answered, not good with computers. I'm trying to work out what happens with fuel the pump when the bike is started. Doesn't seem to pump fuel. I've directly connected pump to battery which makes 1 click sound, I've tested cable continuity from relay to pump and ecu. Should the pump continuously make a noise? Thanks

 

No, pump only works until carb-bowls are filled. So if you’ve ridden bike in past week, bowls are still full, so pump may make one click and stop.

Then when engine is running, pump is not powered full-time. It is activated by pulses from ignitor. At low RPMs, there’s few pulses per second and little petrol pumped. At higher RPMs, there’s more ignition pulses and more petrol is pumped to meet higher demands. Ingenious solution to variable flow-rate without resorting to computers.

 

Ok, thanks very much