What about the quality of the fuel, i.e. the amount of ethanol? Is the problem of the failing pump the use of modern fuel with 10% ethanol? For the moment I don't use this fuel, but buy the more expensiv old fashion fuel, which is sold in Germany (Super Plus instead of Super E10). My Dreirad is from 2013 with 20.000 km, no problems so far with the pump.
Achim
4 aircooled cylinders, 7 tires, not waterproof: my m3w Bluebelle (2013) and my 2CV Gundel (1990)