They were peeling before the FX range ... I've got a 40FSR (vintage 1981) with a peeled liner. Fortunately it's peeled below the ports and the engine still runs like a swiss watch. Just got a 91FX in the air ... wow, it's fantastic in my 60 sized pattern plane, swings a 13x10 @ 10500rpm on 5% nitro / 15% Klotz + 5% BeNol. I've read so many posts claiming this engine is a POS but I can't agree, mine is excellent. Yes, it's an older model with the needle hard mounted on the backplate. That's my 2 bobs worth (that's 40 Aussie cents).
RTD