wrote:
(followups set to r.a.owning)

In rec.aviation.owning Robert M. Gary wrote:
The fuel shop fixed my fuel servo by replacing the spring that holds
the fuel regulating diaphragm. The tech said the previous spring was
very stiff and he replaced it with one that was softer. Does that
indicate that the previous spring was broken (i.e. stiffer than it
should have been) or does Lycoming (Airmotive really) have a variety
of springs for adjustment purposes??

I don't know anything about fuel servos. But I have played with springs
before. For compression springs made out of a piece of wire that is
coiled up, the common failure modes seem to be: 1) breaking into pieces,
2) getting less springy over time - in other words, when new, a 10 lb.
force caused 0.25" deflection, but now a 10 lb. force causes 0.5"
deflection, and 3) taking a set - the springiness is about the same but
the free length is shorter than when new. I guess getting _more_
springy over time (10 lb = 0.25" new, 10 lb = 0.1" now) is possible but
I don't think it's very common.

Thanks!