My machine starts easily but as soon as it does, the wire starts whirring and the throttle appears to be stuck at full throttle for the whole duration I am using it. Today I did over an hours strimming (one tank full) and my hand/fingers were tingling having used the machine at full throttle all this time. I have tried WD40. I cannot strip it down as I do not have a screwdriver to fit. Is it a TORX screw?

Margaret Elliott, June 2009