on the belts point, when you have a pulley with more than one belt if you have belts that are even slightly out size wise, the slackest belt will usually, after it has run in, slip, then acting like sandpaper will wear the sides of the pulley where it sits rapidly,I have seen this happen on new sets of pulleys and belts then been sent back within a day or two to find the pulleys gone again, and also you tighten the belts more to take up the slack in the bigger belt and again it knackers the bearings,
just more dribble
I HAVE MORE!!