Thanks for the feedback. I have just about all the BUSA 1/4 scale planes and this is the only one that breaks the solder joints. I use Stay Brite solder, but it still breaks. Unfortunately, you can't use straight silver solder because the joint has to be soldered on the airframe to insure proper alignment. Using a torch would destroy the airframe. I'll try to lean out the engine to see if that makes a difference.
Thanks,
Ray