OK, I have a Hobbico Superstar RTF. The whole box sat in an attic for about 6 years brand new. Now, I have about 60 minutes breaking in the OS 40LA engine on the ground, but it seems to have a rough idle. The engine at idle without the main wing on, the plane vibrates and the tail feathers vibrate like crazy, very uneven "4-stroking," if I understand that correctly. So I put the wing on and that seemed to stop the tail feathers from vibrating. This plane has been in the air one time at the hands of a veteran who I asked to trim it out for me, no poblems. But tonight just trying to run another tank of fuel through, I left it alone for several minutes at idle which was a bit irregular and then it died which could have resulted in a deadstick had it been in the air. There was still 1/4 tank of fuel. Otherwise throttle responds fine through full RPM.

Is this a break-in issue, or do I need to mess with the low speed idle? If so how? I haven't changed the factory needle valve settings. Just as comparison, I bought an old trainer with a well-broke in Magnum 40 and it purrs at idle all the way through full throttle.