1998 Other Mazda Models bogs down after timing belt changed

I have a 1998 mazda b2500 2.5L on which the timing belt broke. I tried starting the engine twice before checking under the hood and noticed the broken timing belt. I had it replaced by a mechanic, but now it bogs down upon acceleration. It idles fine but the engine sounds different and lacks power. The mechanic told me that it may be the valves got bent, though he told me the compression and fuel pressure were good after checking them. What could be wrong, should I take it to another mechanic?