I've heard it vary pretty greatly on rebuild intervals from 30 hrs to 100. For a beginner rider who doesn't race but rides a mix of small home made mx tracks, some fast fire roads and some tighter trails. And rides a few hours each weekend in the spring/summer maybe a little in early fall. With all that how many times a year would a 250 2t need a top end? I also hear alot of people around here say that a 2 stroke requires more routine maintenance than a 4t but its just cheaper. Is that true?