'85' Yamaha 60 Tri-zinger (atc) is loosing power. carb problem?

I replaced the spark plug. I cleaned out the gas tank- it was full of dirt and sand.
I cleaned out the carburator- it was filthy. I made sure everything in it was clean. However, I failed to count how many turns the air mixture screw was out before taking it out.
I put it back in the atc and it's running better than it did before. But while riding it at full throtle it feels like it looses some power for a couple seconds and then it regains it again.
Does anyone know how many turns out the air mixing screw shold be? How should I adjust the carb?

or any suggestions on what else could be causing the problem?
I'd appreciate any tips.
thanks

jaime
November 2005