Rev Counter Jumping at High RPM
in 912 / 914 Technical Questions
10 years ago
Searched Forums and nothing came up, so...
RANS S-12S
912UL w/HC Cylinders (93HP) - 350 hours (93 octane, No ethanol)
Dynon SkyView Engine Module connected to Rev Counter
Previous flight testing led to T/O RPM up to and above 5300 RPM, but accurate reading above 5300 not attainable. Once this RPM was reached, the RPM would jump around between 5100 and 6000. During initial flight testing kept RPM below 5100.
Prop/Pitch combination changed for cruise, allowing 4900-5000 RPM for maximum T/O power. At level cruise maximum wide open throttle (WOT) now reaching 5300 RPM with the previously mentioned jumps to 6000+.
Is this cause for concern, or should I ignore the inaccurate rev counter indications above 5300 RPM? Engine speed does not fluctuate at WOT.
Thanks,
Corey
RANS S-12S
912UL w/HC Cylinders (93HP) - 350 hours (93 octane, No ethanol)
Dynon SkyView Engine Module connected to Rev Counter
Previous flight testing led to T/O RPM up to and above 5300 RPM, but accurate reading above 5300 not attainable. Once this RPM was reached, the RPM would jump around between 5100 and 6000. During initial flight testing kept RPM below 5100.
Prop/Pitch combination changed for cruise, allowing 4900-5000 RPM for maximum T/O power. At level cruise maximum wide open throttle (WOT) now reaching 5300 RPM with the previously mentioned jumps to 6000+.
Is this cause for concern, or should I ignore the inaccurate rev counter indications above 5300 RPM? Engine speed does not fluctuate at WOT.
Thanks,
Corey
