Hello all, I happened upon this forum while searching for an answer to my current problem.
I'm working on an older model Stihl FS46 trimmer. Initial issue was that it would not crank. This is my neighbors trimmer that he asked me to look at for him. I rebuilt the carb, it had been sitting and had the typical ethanol build up, little particles throughout it. Put it back together, no go. Tested the plug, no spark. Disassembled outer case to get a better look. Contact points between magnets and ignition coil were corroded/rusted. Took ignition coil off, cleaned contact points of it and magnet surface, gapped @ .012" assembled everything back.
Well....now it fires right up, but, it's stuck in fast idle, trigger has zero effect. I have set carb screw settings to factory, as well as trying to adjust, no change. I checked throttle cable, it's not holding carb at WOT, does this even with no cable attached. I even tried another carb that I KNOW to be good, and same thing, high idle, way too high. Of note, I also disassembled the trigger assembly, it all seemed fluid to me.
I'm wanting to think possibly a vacuum leak, but where? Carb to block interface looks tight? Am I missing something obvious? I've read A LOT of entries on the internet before settling on this site to ask my question, appears to be some sharp guys in here.
Thanks for reading my short novel, I just wanted to include any and all clues that may help with my issue, I'm not too proud to admit, I'm stumped!
Thanks,
Jason