Oddball Engine Shutdown Procedure

[kontiki]

I was reading up on Lycoming engine recommendations and ran across this shut down procedure.
I didn't find it in other Lycoming operation manuals and hadn’t heard of it before.
Anybody running it up 1800 RPM, then dropping sown to 1000 then idle cut off like it says?
Anybody know why?

 

[Geico266]

The paragraph you highlighted is for shut down after ground operations. It sounds like they are running the engine up then dropping it before shut off to avoid fouled plugs. Most pilots run as lean as they can on the ground to avoid fouled plugs, or run mogas.

 

[kenjr]

I saw that too. I'd only do it if I wasn't leaning on the ground. If you are doing that - I don't think the quick runup before shutting it down does much, if anything.

 

[JGoodish]

I was reading up on Lycoming engine recommendations and ran across this shut down procedure.
I didn't find it in other Lycoming operation manuals and hadn’t heard of it before.
Anybody running it up 1800 RPM, then dropping sown to 1000 then idle cut off like it says?
Anybody know why?

I follow the Lycoming recommendation as cited. I also aggressively lean the mixture during ground operations, but the shutdown procedure has made a noticeable difference in the long-term cleanliness of the plugs in my O-360.


JKG

 

[PilotAlan]

I run up and pull the mixture so that the prop inertia runs the engine through several dozen revs with no fuel, so the chances of having a charged cylinder ready to bang and spin the prop during ground handling is lowered.

 

[Meanee]

My CFI did it so I kind of doing it myself as a habit. But really briefly, not few minutes like one manual I saw one recommended

 

[frfly172]

When I rented we always did the run up before shut down,also leaned for taxi.

 

[Dr. O]

Everything old is new, again.
Clearing the plugs before shutdown was known to Lindbergh - and all the old tyme pilots.
Plug fouling was a bigger issue in those days - for a number of reasons, including round engines with upside down cylinders.

Today's engines/plugs are much better. Every airplane is different. You gotta figure out what your plane needs.
I have had one fouled plug in the past 14 years - and I was pizzed.

Leave the mixture lean when entering the pattern.
When you reduce throttle, lean some more.
When you add carb heat, lean some more
Do not go full rich on short final like your cfi yells about - if you have to go around, then put everything to the firewall
Taxi with it leaned enough to stumble just a bit.
Your engine will thank you.

 

[Art VanDelay]

You think that's an oddball shutdown procedure you should see what you have to do on an M-14 Radial !

 

[Aztec Driver]

Also a necessary procedure for those of us with generators. Need to charge up the battery, especially after a long night taxi with all the lights and radios draining the battery.