Gents, I have a fs90, it’s about 3-4 years old. I’m trying to install the echo speed feed 400 on it and I’m having a hell of a time. The manual says for stihl fs90 I should use the LH2 set up which is the gold nut thing and the silver screw that goes inside. However I cannot get the threads right. I’ve tried and tried and tried (turning it cc of course) and it just doesn’t seem to wanna go on. I can get it to start but it gets into a bind almost immediately. Is there something I’m doing wrong? I’m mechanically inclined and know not to cross thread and stuff but this is just throwing me for a loop. Any other fs90 fans out there can give me some insight?