I just was given a ten year old Stihl blower BR 400. It seems to work okay, but I think the idle set screws are not as good as they could be. It has three set screws, one low, one high, and one below that is larger? Anyone have experince in the proper way to adjust these three screws for best operation at idle and high output? I do not have any manuals at all for this blower so I would appreciate any help. Does anyone know an online place to get or review an owners manual for this old blower? THANKS!