I bought a Stihl KM85 trimmer and have gone through 3 carbs since purchasing this June. This unit comes with a ZAMA carb. It seems that the base plate of the carb body is warping. I have no problems with replacements that are covered under warranty. But with each carb lasting no more than 2 months I'm concerned that this problem will continue till the warranty runs out. That means the trimmer will only last a year. Does anyone have any suggestions on how to handle this problem?