Mike G
Junior Member
- Joined
- Jun 16, 2005
- Messages
- 1,917
- Location
- Lillebonne France
- Aircraft
- Owned Magni M16 now ELA 07
- Total Flight Time
- 550FW + 500 gyro
What differences do you see in 914 exhaust temps?
After a long break I finally got my 914 back together. It started OK but won't run below 2000 rpm without shaking itself so badly it hurts. At 2500 it smooths out but is still vibrating and at 3000 it is a bit smoother but still seems to be missing.
I get the following :
rpm 3000 3200
cyl 1 600 590
cyl 3 616 660
cyl 2 628 647
cyl 4 730 738
degrees C
I compression tested the cylinders and they are all good although cyl 1 is a fraction lower than the others. What compression pressure would you expect from a 914? I got between 10.5 and 11 bars (152 to 160 psi)
I balanced the carbs at 2000 yesterday when it ran much smoother and they are balanced.
I suspect the idle mixture screw but it's unaccessible with the old style drip bowl under the carbs. When I rebuilt the carbs I set them at the recommended one and a half turns open.
I'm trying to establish how important these different temperatures are and can they point me towards the fault.
Mike G
Any comments or ideas would be welcome.
After a long break I finally got my 914 back together. It started OK but won't run below 2000 rpm without shaking itself so badly it hurts. At 2500 it smooths out but is still vibrating and at 3000 it is a bit smoother but still seems to be missing.
I get the following :
rpm 3000 3200
cyl 1 600 590
cyl 3 616 660
cyl 2 628 647
cyl 4 730 738
degrees C
I compression tested the cylinders and they are all good although cyl 1 is a fraction lower than the others. What compression pressure would you expect from a 914? I got between 10.5 and 11 bars (152 to 160 psi)
I balanced the carbs at 2000 yesterday when it ran much smoother and they are balanced.
I suspect the idle mixture screw but it's unaccessible with the old style drip bowl under the carbs. When I rebuilt the carbs I set them at the recommended one and a half turns open.
I'm trying to establish how important these different temperatures are and can they point me towards the fault.
Mike G
Any comments or ideas would be welcome.