Let me state the obvious and incur the wrath of the community:
This is not a job to experiment with - you either do it right or you don't do it at all.
A loose belt will at best allow you to retention it if nothing has happened - at worst it will jump a tooth or more or even come right off requiring an engine replacement at this age.
A too tight belt will at best allow you to slack off on the tension if nothing happened and it was only noisy - at worst the belt itself can break or more likely the nose of the crank can be broken right off (see the huge number of threads on this topic here already) also requiring an engine replacement.
Don't F**k around with this - if you are lucky to have a motor still running with an improperly adjusted belt and didn't understand the manual the first time round, make damn sure you do it right the second time round by removing the covers and following the manual - the fact that you guys are asking all sorts of funky questions leads me to believe any other method is bound to end in misery as a result of inexperience.
