Boost Pump ON or OFF for Takeoff? Landing?

My "new to me" (coming up on a year new-to-me, anyway) RV-4/Lyc IO-360-B1B, has takeoff and landing checklist placards. Both call for the boost pump to be "ON" for takeoff and landing. A checklist I have from a Piper Arrow/IO-360 also calls for the "Fuel Pump" to be ON for takeoff and landing.

Ok, so far, so good. But...

I've been reading all those Pelican Perch articles on AvWeb, and the author John Deakins talks about the boost pump NOT being on for takeoff or landing, that it can flood the engine. I've never seen that happen, but what-the-heck anyway?

Which is correct, Boost Pump ON or OFF for takeoff and landing?

Typically on a LYCOMING you want the boost pump on for takeoff and landings to minimize the risk of engine failure due to a mechanical pump quitting during that phase of flight. In cruise, you would have time to diagnose the failure and hopefully restore power.

However, on a CONTINENTAL, they use a different setup and if you use the electric boost pump WITH the mechanical pump, it can and will flood the engine. If the Continental mechanical pump fails, the electric pump can supply the fuel, but two pumps to too much.

Is your Pelican article talking about Lycoming or Continental?

Taltruda said:

Typically on a LYCOMING you want the boost pump on for takeoff and landings to minimize the risk of engine failure due to a mechanical pump quitting during that phase of flight. In cruise, you would have time to diagnose the failure and hopefully restore power.

However, on a CONTINENTAL, they use a different setup and if you use the electric boost pump WITH the mechanical pump, it can and will flood the engine. If the Continental mechanical pump fails, the electric pump can supply the fuel, but two pumps to too much.

Is your Pelican article talking about Lycoming or Continental?

Click to expand...

Now that Continental makes Lycoming-type engines (IO-340), it is a little fuzzier. It's all in the operator's manual, of course.

Taltruda said:

Typically on a LYCOMING you want the boost pump on for takeoff and landings to minimize the risk of engine failure due to a mechanical pump quitting during that phase of flight. In cruise, you would have time to diagnose the failure and hopefully restore power.

However, on a CONTINENTAL, they use a different setup and if you use the electric boost pump WITH the mechanical pump, it can and will flood the engine. If the Continental mechanical pump fails, the electric pump can supply the fuel, but two pumps to too much.

Is your Pelican article talking about Lycoming or Continental?

Click to expand...

Excellent! The author - in all the articles - seems to always focus on a Continental "flat-six" engine of the kind in his Bonanza, so I'm betting your explanation here answers my question.

If only he'd have taken the time to point out this difference between the two engine manufacturers...

Thanks!