Prop control all or nothing

[mshac]

I think Kim is right. When you do a run-up check at 1700-2000 rpm, all you're doing is making sure the props will feather.

Do your governor check again at full take off power (on one engine at a time) and see if the results aren't different.

[YankeeClipper]

I will definitely try that. Surprised my IA doesn't know this though (even if he isn't a pilot).

[cjordan]

Not sure about what you have going on. I usually run to 1800, check mags then push to around 2000 to cycle.( Never see anything near stall here, maybe 500rpm drop or so) Next pull back to 1500 and take it all the way to feather check, pulling all the way back with the (to the right and back to the stop on prop control procedure) That pulls the motors way down as you describe. Don’t see this on initial though run up though.

Sounds like governor (or linkage) issue if you aren’t deliberately going to feather on initial run up.