Carburetor Sync
in 912 / 914 Technical Questions
7 years ago
I just recent synced my carbs on my 912ULS. The aircraft is a Vans RV-12 with approximately 512 hours.
I did both a mechanical and pneumatic sync.
Two questions:
Question 1:
When I did the mechanical sync; when I moved the throttle from idle to full open, one throttle arm was fully extended and the other one had about 1/16 to 1/8 inch of play. In other words, it appears fully open until I pushed on the arm and it moved a tad more. I loosened the nut and re-tightened the nut two more times with the same results-just on the one carb. It almost appears that there is some play in the throttle arm. Is this acceptable? If not, please recommend a solution.
Question 2:
When doing the pneumatic sync, I was able to get the gauges to agree at idle (around14.5 inches) and at 2500 RPM (around 11.5 inches). However, as I moved the throttle to full power, around 3300 RPM, I was showing around 9 inches on 1 carb and around 8 on the other. As I continued to move the throttle to full power, they seemed to get in sync again and if I remember correctly at full power they were showing about 5 inches each.
Is this acceptable? I do not remember having seen this in the past, but I may have missed it.
Is there any chance the two issues are related?
Thank you for your help.
I did both a mechanical and pneumatic sync.
Two questions:
Question 1:
When I did the mechanical sync; when I moved the throttle from idle to full open, one throttle arm was fully extended and the other one had about 1/16 to 1/8 inch of play. In other words, it appears fully open until I pushed on the arm and it moved a tad more. I loosened the nut and re-tightened the nut two more times with the same results-just on the one carb. It almost appears that there is some play in the throttle arm. Is this acceptable? If not, please recommend a solution.
Question 2:
When doing the pneumatic sync, I was able to get the gauges to agree at idle (around14.5 inches) and at 2500 RPM (around 11.5 inches). However, as I moved the throttle to full power, around 3300 RPM, I was showing around 9 inches on 1 carb and around 8 on the other. As I continued to move the throttle to full power, they seemed to get in sync again and if I remember correctly at full power they were showing about 5 inches each.
Is this acceptable? I do not remember having seen this in the past, but I may have missed it.
Is there any chance the two issues are related?
Thank you for your help.
