Magneto Drop
in 2 Stroke Technical Questions
13 years ago
I have bought a second hand JORA microlight aircraft equipped with an inverted Blue Head 582 UL 99 engine. The engine has 203 hours since new. I know that both the aircraft and the engine were jealously maintained by the previous owner...but there has been a problem that no body seems to have been able to explain or solve. The problem is that when making the mag checks when one mag is switch off the drop is of about 150' but when the other is switched off the drop is of about 700-800'. And yet the engines continues to run without missing beat-water temperature remains at 80*C and EGTs firmly within operational range. Can some one tell me why this abnormal drop? Is there a cure for this?
Strangely enough on another microlight we have a 582 UL DCDI (not Blue Top). It has been recently overhauled at a Rotax authorised centre in Sicily Italy. I was having a problem because my 12V was not charging and some one suggested that I had a defective regulator/rectifier. Without thinking twice I got a new regulator/rectifier and replaced the defective one which as declared 'burnt'by an electician. But the thing is that after replacing the regulator when making mag checks, the Left mag drops about 200' but the Right mag INCREASES by about 300'!! Furthermore when we switched wiring the Left mag increased by about 300' while the right mag dropped by 200'. And above all the battery is still not charging! (when I had the 'defective' rectifier I never experienced this abnormal mag drop behaviour).
Finally - back to the Jora. The Rotax 582 Blue Head installed has a WoodComp 3 blade propellor pitched at 12 degrees (can be pitched to 17deg) At maximum full take-off power I get 6,800'. At 5,800' my airspeed is only 50knots. Can I achieve a better cruising performance by increasing the pitched from 12 to say 14 degrees?
Strangely enough on another microlight we have a 582 UL DCDI (not Blue Top). It has been recently overhauled at a Rotax authorised centre in Sicily Italy. I was having a problem because my 12V was not charging and some one suggested that I had a defective regulator/rectifier. Without thinking twice I got a new regulator/rectifier and replaced the defective one which as declared 'burnt'by an electician. But the thing is that after replacing the regulator when making mag checks, the Left mag drops about 200' but the Right mag INCREASES by about 300'!! Furthermore when we switched wiring the Left mag increased by about 300' while the right mag dropped by 200'. And above all the battery is still not charging! (when I had the 'defective' rectifier I never experienced this abnormal mag drop behaviour).
Finally - back to the Jora. The Rotax 582 Blue Head installed has a WoodComp 3 blade propellor pitched at 12 degrees (can be pitched to 17deg) At maximum full take-off power I get 6,800'. At 5,800' my airspeed is only 50knots. Can I achieve a better cruising performance by increasing the pitched from 12 to say 14 degrees?
