“Oldtime” water delivery: Use a carburettor!
A carburettor sized as for gasoline use on the same motor; now it would have half the flow velocity, if the “gasbranch” (the other is air) used equally much air as it delivers gas.
But the air consumption is ~60% of the gas delivery.
So, on the “gas-side” 50% of what the motor takes, and that times 0,6.
This is the actual flow: 0,5 X 0,6 = 0,3 of what the motor takes.
This max flow is floppy and does not add too much resistance to the air intake.
Additionally, one can reduce the water consumption by putting a copper (enamelled) wire in the main nozzle in the float chamber, the one delivering to the channel leading to the throat nozzle.
Copper wire diameter 0,7 of the nozzle diameter will leave a passage of 50% of the original.
In winter time one can leave out the float and deliver the water from a tank lower than the carburettor with a 24Volt windscreen pump. Delivers enough, lasts longer.
Delivering restricted (1-2mm) at the float chamber bottom; flows back when shut down.
Overflow hose (4-5mm) at desired level, self-regulating, slurps air bubbles into the overflow/return hose going back to the tank.
Motor coolant (copper) line melts frozen tank.
Well designed in less than 15 minutes… if 5 liters,
at -35 degrees Celsius.