912 ULS Engine "missing"
in 912 / 914 Technical Questions
12 years ago
My Rotax 912 ULS is in a RAN-6 amphib. 750 hours on engine, carbs synced about 25 hours ago. I burn primarily 91 octane non-oxy, but sometimes add 100LL. Have 50 hours on new spark plugs that were re-gapped according to rotax recommenation. It runs like a top the vast majority of the time, like months at a time (50 hours) for. However, every once in a while, the engine "misses". Not once, but several times, some times just a few hic-cups or on up to maybe 3-5 minutes. It then resumes running smoothly. It can occur during climb and cruise. I don't ever rememebr it occuring during descent/lower power settings. It most recently occured following water ops yesterday. When the miss occurs, the RPM gauge stays stable, giving no indication of loss of RPM/power. Yesterday the temp gauge was slightly in the yellow band. I observe the 5500 RPM limitation and we set cruise power at 5000 RPM.
I routinely buy the 91 octance from the same gas station, yesterday it was bought at another location.
It would be nice to get to the bottom of why this occurs and what I can do to prevent it.
Any ideas would be appreciated!
Reid
I routinely buy the 91 octance from the same gas station, yesterday it was bought at another location.
It would be nice to get to the bottom of why this occurs and what I can do to prevent it.
Any ideas would be appreciated!
Reid
