Sargento

Well it’s been a while, the weather have been really unfavorable. I took my decathlon for some air time a few weeks back and kept having bubbles in the engine lines. This caused it to keep leaning and shutting off. I took the engine off the plane and put it on a stand, it ran great, no bubbles at all. This past weekend I put everything back and guess what?... yep.. Bubbles again. I have an OS 50SX.

I increased the foam padding but this did not seem to have much effect, it helped some but did not solve the problem. So far I have changed the fuel tank, fuel lines, padding, propeller, spinner and installed rubber disks between the mount and the firewall. The engine is now running more reliable but at mid throttle I still get some annoying bubbles.

I do not know where to go from here. I know this bubbles are been caused by vibration as it runs all day on the stand, and no bubbles are been formed. I do not have a cowling on the plane. Another thing I changed was the fuel, I went from 15% to 10% this seem to have helped me some.

I have a feeling that the problem is with the fuel tank padding, maybe I have too much now. How do you guys have the fuel tank installed? Do you guys use foam padding until it is secure in there (that's how I have it) or you hold it with plastic ties, Velcro or some other way? If anyone can shine in some light I will appreciate it.