912 Mag Drop issues
in 912 / 914 Technical Questions
8 years ago
I have an issue with my Pipersport 2010 Serial # 1 Rotax 912 975 hours.
Annual done in January. Aircraft developed a canopy lock issue in March which required removal and shipping to TX TWICE! Sport was hangared for 3 months. With canopy fixed run-up at 4000 rpm good, attempted flight check an could not get full power on T/O roll 4400 rpm. Next attempt different day Mag check failed with >300 drop on L Mag. Subsequent maintenance visit pulled carbs and checked bowels and main jets. Found right main jet restricted. Cleaned and replaced O rings and bowel gasket. Drained left main tank of old autogas and filled with fresh
Next run-up mag checked good at 4000 <100 drop per and high speed run produced 4950 RPM (normal). Return to ramp and before shutdown checked mags and again found >300 drop on L Mag.
Removed Cowling and swap’ed firewall side IGN module connectors. Run-up at 3000 RPM with no issue Mag drop both sides <100 Returned IGN modules to stock setup and still no Mag issues.
Originally on the high speed run CHT 215-230 On taxi in 250 and on ramp before cowl removal 245. We have always had heat issues in Miami in the summer and have to be careful of overheats. Rubber replacement was completed on annual but spark plug wires and caps are still original.
Charlie
LSRMA
Annual done in January. Aircraft developed a canopy lock issue in March which required removal and shipping to TX TWICE! Sport was hangared for 3 months. With canopy fixed run-up at 4000 rpm good, attempted flight check an could not get full power on T/O roll 4400 rpm. Next attempt different day Mag check failed with >300 drop on L Mag. Subsequent maintenance visit pulled carbs and checked bowels and main jets. Found right main jet restricted. Cleaned and replaced O rings and bowel gasket. Drained left main tank of old autogas and filled with fresh
Next run-up mag checked good at 4000 <100 drop per and high speed run produced 4950 RPM (normal). Return to ramp and before shutdown checked mags and again found >300 drop on L Mag.
Removed Cowling and swap’ed firewall side IGN module connectors. Run-up at 3000 RPM with no issue Mag drop both sides <100 Returned IGN modules to stock setup and still no Mag issues.
Originally on the high speed run CHT 215-230 On taxi in 250 and on ramp before cowl removal 245. We have always had heat issues in Miami in the summer and have to be careful of overheats. Rubber replacement was completed on annual but spark plug wires and caps are still original.
Charlie
LSRMA
