I have a G 90 that that I bought new in 1998 (Italian made). It's been in the box since this spring. I finally finished the Topflite P-51 that I bought it for this spring. I followed the break-in procedure with the engine mounted to my test bench. During the break-in I didn't notice the excessive vibration. The test bench probably absorbed the vibration.

I noticed the vibration the first time I ran the engine on the plane. After 30 seconds of running the vibration was so bad it broke the hinges on the rudder. I was using Du-Bro nylon pinned hinges. I brought it home and re-checked the balance of my 12X8 prop and the 4" C.B. Associates spinner. They both balance.

Is it worth sending it in to Hobby Services to have it looked at?

Would I be better off just buying a new one with a warranty?
(or)
Is something I can do to fix it myself?

Thanks for the help.
Al

One way to change the vibration mode is to try different propellers. Your airframe/engine combination may be vulnerable to different modes caused by the prop. Even different brands of propeller that are the same diameter and pitch will have different affects.

Also, please be aware that many airframes today have less substantial construction than did airframes of just a few years ago. Also, people are putting larger engines on models originally designed for smaller ones. This is all in concert with the popularity of airplanes that can perform "3D" flight.