when I am cruising at ~9k rpm and I quickly open the throttle up the engine initially seems like its moving the rear wheel as it should be (i.e. the bike speeds up a bit). but then it simply stops, the rpm's shoot up much more rapidly w/o the bike gaining speed. after about 1/2 to 1 second the rpm goes back down to about 10k and it seems like the engine has once again "caught" the rear wheel and begins to accelerate slowly. the whole time my hand is keeping the throttle open by the same amount. is this normal?