I see the Walbro 342 is a suggested replacement for Acura/Honda models with the smaller engines. I really can't see any downside to using a pump with a significantly larger than required flow rating, except maybe cost. When researching alternatives, I found very few rated below 100Lph, and their form factor was quite different.
Remember the 255Lph rating is a maximum rating with zero restrictions at a test voltage. To know the actual flow volume on the M3W as installed with the pressure regulating filter, one would need to actually measure it.
I've measured carbureted engine fuel system flow volume by running the hose into a suitable container for a precise amount of time (usually 30 seconds) then measuring the output. Repeat 3-4 times then average the results. Typical results were in the 15-30 gallon/hour (or roughly 60-120Lph) with small Facet or OEM electric pumps, serious overkill for the LBCs I was working on.
