A friend of mine has a Stihl br 550 4 mix back pack blower and it has a steel wire running all the way through the blow tube. At the end of the tube the steel wire hooks to a peice of plastic and has 5 or 6 wires hanging off the end of it. Can someone pleae explain the purpose of this wire. Also this blower shocks the crap out of you when using it. Thanks in advance for any information!!