I have a Stihl FS80 trimmer that is less than two months old. There is a good bit of oily residue being discharged out the exhaust. I know some buildup is normal since I own another Stihl trimmer. But there is so much that I have to wipe is down after only 20 - 30 minutes of run time or else it will start running down the outside of the housing. Have any of you guys ran into a similar problem and if so what did you do to remedy it? Thanks for any help.