Could this be timing belt?

Hi
Just bought Honda accord 1,8 ls. I owned lots of cars before but never I had a japanese car. This car impressed me a LOT; even that I owned Audi A6 quattro before. I got a 1996, metallic blue, full leather, AC, 85kW Honda with only 110.000 km. I took it to mechanic to change the bearing on alternator and to replace the old timing belt with new. So new timing belts- both and new tensioners. When car came back i noticed that now there is more "valve play" to hear. I have a feeling that car has less torque from 2000-3500RPM. And it turns only to 6800 RPM and than gets the blockade. Before it turned to 7500 and I found no blockade. Mechanic says everything is OK and he just needs to adjust the valves. I think he did not put one of shafts in right position. Please help me for I don't want to go back to him for "valvea adjustment" if there is indeed something wrong with timing belt position.
PS: Car is not getting any hoter but we have 10 degrees Celsius today.
Regards