I had the very same problem with my Tornado BB after break in. My problem was that I got over zealous with my tuning and messed everything up. Set all screws back to factory and started over with very small adjustments and everything was fine. You might also want to check your clutch shoes. Sounds like your clutch might not be engaging. Could be the spring or shoes are worn.

EDIT--Almost forgot. Another thing to consider is what kind of fuel you are using. There are some fuels out there with an additive that will cause the car to bog if you tune to lean. Supposed to keep noobs like me from blowing motors while learning how to tune. Anyway, just take a step back and check everything you can think of that would cause a power loss.