912ULS EGT overheating
in 912 / 914 Technical Questions
9 years ago
Hi,
I have a 912 ULS engine installed. I flew yesterday and everything was normal. This morning during engine warmup also everything seemed normal.
During my takeoff i used my usual takeoff procedure by slowly adding power until full power in my taildragger aircraft. When climbing through 200ft agl i noticed both my EGTs above 900C. I immediately did a low power low altitude turnaround and land the aircraft.
I runup the engine on the ground within the EGT limits and discovered that it can not do above 4000rpm otherwise it would go outside the allowable range. I also noticed that the CHTs and oil temp were hotter than normal after some time of ground runups.
As this pointed out to me for either instrument fault or a lean running condition, i inspected my sensors as well as MAP/carb balance tube for signs of leakage. Nothing found.
I then opened the carb bowls to check the jets for blockage. What i found was that when I opened the bowl, as soon as the needle opened there was some pressure released from the fuel intake. Don't know if it was air trapped in the fuel line or just normal release of fuel pressure...
Note that the engine had no signs of rough running or hesitation at takeoff. I did a runup again after checking the bowls (and releasing whatever pressure was trapped in the fuel lines) and so far temps look good. I don't want to fly the aircraft until i am certain what the cause is, as i dont want an EFATO..!
Regards
Jacques van der Westhuizen
I have a 912 ULS engine installed. I flew yesterday and everything was normal. This morning during engine warmup also everything seemed normal.
During my takeoff i used my usual takeoff procedure by slowly adding power until full power in my taildragger aircraft. When climbing through 200ft agl i noticed both my EGTs above 900C. I immediately did a low power low altitude turnaround and land the aircraft.
I runup the engine on the ground within the EGT limits and discovered that it can not do above 4000rpm otherwise it would go outside the allowable range. I also noticed that the CHTs and oil temp were hotter than normal after some time of ground runups.
As this pointed out to me for either instrument fault or a lean running condition, i inspected my sensors as well as MAP/carb balance tube for signs of leakage. Nothing found.
I then opened the carb bowls to check the jets for blockage. What i found was that when I opened the bowl, as soon as the needle opened there was some pressure released from the fuel intake. Don't know if it was air trapped in the fuel line or just normal release of fuel pressure...
Note that the engine had no signs of rough running or hesitation at takeoff. I did a runup again after checking the bowls (and releasing whatever pressure was trapped in the fuel lines) and so far temps look good. I don't want to fly the aircraft until i am certain what the cause is, as i dont want an EFATO..!
Regards
Jacques van der Westhuizen
