One thing which confuses a lot of owners is whether there is a return to the fuel tank.
I think most/all Conti engines have one, while no Lyco engines have one.
So, on Conti engines, any fuel totaliser system has to have the transducer mounted on the inlet pipe to the fuel distribution spider, while on Lyco engines it can go into the pipe between the HP fuel pump and the fuel servo.
It also means the fuel pump type must differ. With a Lyco engine, it has to have an internal relief valve, so it generates a constant pressure at the fuel servo input. A gear pump won’t do that, and would “blow up” if the mixture lever was shut while the pump was running.
Continental engines have vapor return, not all have fuel return.
