Hi , I've got an older Stihl FS 65 AVR trimer with a Walbro carburetor. I'm trying to find the OEM # for a carburetor kit for it. The # on the carb. is a little hard to read but I think it says WT388.1 or 38B.1. The trimmer's S/N is 13665300 and there is also a tag on the trimmer that reads 5YA07 but I don't know what that's for. The Walbro kit OEM # is K20-WT or K20-WAT but the fuel pump diaphram doesn't look the same as mine. And the FS 65 AVE isn't listed on Walbro's PDF OEM parts number list. Thanks , Scott