Hi Dave,
I've had many YS engines (at least 10) and all run great !
Except for this new YS 91 FZ.
(Bought two from Central around January)
Have tried everything in the book !
Idles ok in the ground (around 2000 and steady).
Top end is superb (9000 with 15X8), transitions smoothly,
Wildcat 20/20 - F plug.
BUT after a full flight, it just dies when I throttle back
for landing, even if I try not to idle under 2500.

Any suggestions ?
Happy flying
George Brod