99 r6 running no bueno

Okay so have had my 99 for not even a week now have had MANY of the normal issues but now im having a kind Pull-smooth-yank-smooth thing going on while riding at steady speeds. (have new chain and sprockets on the way) But what is really bugging me is the fact that at high way speeds in the upper gears the bike has 0 power, like none. as I come out of the throttle it reacts and surges forward until I get back into it. have new plugs to put in but wanted more guidance before I spent any more money! HELP