Mixture setting before start

[Ted]

Do IO Lycomings have fuel return lines to a header tank?

On IO Lycoming-powered Cessnas (at least the 182, as I recall, I think also the 172 and 206) they have a "vapor return line". It was one of those things that Cessna dictated they must have because they thought it worked.

Do any factory IO systems use purge valves?

My new exp has Airflow Performane mecanical injection (no fuel return) and uses a zero leakage servo so no purge valve. I've been advised to get in the habit of turning off the fuel valve at shutdown because zero leakage isn't perfect. I never had to do that in Continentals.

That sounds like an Airflow Performance issue. On the Lycomings I never turned the fuel valve off at shutdown and never had an issue.

 

[Stewartb]

API has a leg up on it compared to Precision's Silver Hawk, which is the exp version of Bendix FI. I have their latest servo and this no purge valve recommendation is new to this servo. Purge valves are interesting.