engine problem failure

I bought myself a '94 MX-3 with a previous KLZE swap two weeks ago. Nothing was wrong with it when I test drove/bought it, except a reeaaally high idle (2100-2300rpm) which the previous owners said was due to chipping the engine, and a real rich running problem, one so bad I got a headache...

Hi there, i am considering on buying a used Mazda Sport 6 for 2500. The reason why it is so cheap is because he says the engine just wouldnt turn over one day. He believes it is the timing belt but he is not forsure about it, i have lots of time to fix it and think it would be a good hobby, but...