912S3 strange cylinder #2 behavior
Hello,
I tried to find a similar topic but to no avail so here I go :
I own a pipistrel virus sw 121, fitted with a 912S3. This is an EASA CS-LSA certified aircraft, so I can't tweak it much myself, just in case. The EIS is integrated in the Garmin G3X.
There was something bothering since the beginning, but I couldn't really frame it : I was following the aircraft POH for startup: full choke, start, close choke while keeping RPM in the 2300-2400 range with throttle.
And then at some point, say 1 to 2 minutes in, the RPMs would increase by roughly 110. So if I was in the low 2400's, i'd have to reduce throttle a bit to stay below the 2500 RPM threshold.
Now it's a bit colder, and I noticed during startup that the EGT for cylinder #2 lagged behind (EGTs were 548-423-523-544°C 1 minute after closing the throttle). And the engine was running a bit rough, with a low frequency noise. Then 1 minute later, the RPMs would increase, the vibrations would stop, and the EGT for cylinder #2 catch up then exceed the other EGTs and stabilize 50°C higher than the others.
A mag check showed no significant difference between Left and Right, before or after the RPM increase. In flight, the EGT for cylinder #2 has been consistently 40-50°C higher than on the other cylinders.
Have you encountered this kind of behavior ? Should I worry ?
Thanks,
Nick.
