As you learn how to tune the engine some of the vibs will go away, If thats a poulan based engine it will have some vibes no mater what. You have to tell us what make of motor it is. Try leaning the low needle a bit. You can break in the engine without having to run it too ritch. An engine will tell you it is too lean if there is a sag in power when you climb hard. You can turn in the low needle untill you get a hesitation when advancing throttle, then open it back up a bit. If you have an engine in a light plane idle vibes will be more pronounced and you might have to use two rudder servos. Check all screws often especialy motor mount and servo and servo arm screws. Use metal gear servos only and blue locktite them in. If you can't cure the vibe problem get another engine. Find someone that makes an engine based on the Echo engines, or a zdz 40 however the zdz will be a bit more vibs at idle due to its high compression.