Calling engine experts...Engine died at idle

[Skid]

Today while checking the idle during the runup, the engine began to shutter and then die. I scrubbed the flight and wrote it up for maintenance who...didn't seem too concerned...

One thing that may or not be noteworthy: The left mag had a 170-180 drop, which I attempted to clear, but only achieved 150-160, still right on the limit. The airport is sea level and about 32*C out. Not blazing hot but still pretty uncomfortable to which I always try to aggressively lean on taxi to prevent fouling the plugs.

So anyway I was just curious if anyone could give some more information just so I can learn more from the event. From my reading it sounds like merely an out of adjustment idle setting, but wasn't sure if the magneto or temperature would also be a contributor.

Thanks!

 

[Clip4]

Sounds to me like the density altitude was high providing a rich mixture and spark plugs were in serious need of being cleaned and gapped. The idle could also need tweaking.

Do you lean after engine start and during taxi?

 

[Dan Thomas]

The POH might call that mag drop acceptable. I wouldn't. I'd wonder about the mags needing work. A weak spark can become a nonexistent spark when the idle is low. When were those mags last inspected internally?

As much as 90% of engine troubles are attributable to ignition.

 

[Omalley1537]

What drop were you getting on the right mag?