i am thinking about rebuilding or having a tomos motor rebuilt. It runs and drives but makes some noises, so i want to put all new bearings in it and a set of rings. how much should i expect to pay for all new bearings? also i will need a special flywheel puller, correct? any other special tomos tools i need? can these tools be ordered from a tomos dealer and are they very expensive? Also i have two old biturbos laying around but they are missing the gold "Silencer"? does this create back pressure or is it just to cut down on noise.