Just adding on to the band wagon here...
I've just had the 5th cylinder failure (3rd on this motor) while in flight at a Scale Master event... Mid-throttle position, at least 4 minutes into the routine, 21lbs TF GS FW190, level flight...
I have two of these FG60's (originally bought from HH for a TF GS Zero and my TF GS FW190...
it's been either cylinder 2 or 3.. .no loose bolts... I check every bolt before every days flying... I run 17:1 Amzoil with 87 gas...
Folks at my flightline are convinced it's a hydro-lock issue but that's not verified... HH support told me that they don't sell enough of these motors that would force them to rectify in other way than to fix it under warranty.
As a result I feel terribly frustrated and disappointed that I invested so much into motors that will likely fail in the wrong part of the sky and potentially wreck one of my birds. I have several friends I fly with that have 84's that don't have this issue.. .
In the last two years the only issue I've heard about on 84's is that they heat to a lean setting and blow a rod or seize.