RE: Tail bobs
Hey ebay,
Like Nick said, check the blade grips...another thing that drove me crazy one time is that I had the bell mixer arms too tight, and it wobbled everywhich way when I was trying to hover.
A quick check for this is to check the flybar for free movement. It should be very, very free to flop around from side to side. If it is stiff at all, check the mixer arm mounting screws, they may be too tight.
Hope this helps,
Glenn