: The JPI CHT probes are bayonet style except for cylinder 3. Cylinder 3 has a
: JPI washer-type thermocouple under the top spark plug. Consequently, it
: reads lower than the others. The bayonet socket for cylinder 3 is occupied
: by the original Cessna CHT probe. JPI makes a dual bayonet adapter which I
: intend to install sometime.

Just FYI, I went through CHT-probe hell awhile back and ended up with four
spark-plug probes on the cylinders. In the summer, I have a bayonet probe that I swap out
for the heater on #3 (4-banger). The bayonet (the official place to measure CHT, BTW)
reads at least 60 degrees *colder* than the spark-plug probe. I've seen two posts here
that tend to imply the opposite.

It's an issue for me, since in cruise I typically see about 400 degrees on the
spark plug type... a bit too hot if it were true. Since it's actually 350 or less on the
"real" probe, I'm not concerned about it.

-Cory


--
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* The prime directive of Linux: *
* - learn what you don't know, *
* - teach what you do. *
* (Just my 20 USm$) *
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