Preludes should have timing belts replaced around 70-80k. They are one of the few cars that destroy all the valves if the timing belt breaks while the engine is running. I've heard Mitsubishi Eclipses are another infamous model with the same design problem - most American cars are designed so the valves don't get wrecked if the timing belt breaks. The guy I bought my Prelude from said he had already had it done. I found out he had lied when the timing belt broke at 110k...