I have a FS75 Stihl weedwhip that will idle all day, but has no acceleration. When the throttle is wide open, it just bogs. If I feather the choke and the throttle at the same time, I can get it to spin up, and it will stay that way as long as the choke is nearly all the way closed. When I remove the choke, it will go back to idle. Based on this, I have deduced that the main nozzle is plugged. I just bought this used with this problem. I have opened the carb and found deposits at the welch plugs, so I pretty much know that bad-gas/varnish is the problem. The carb that I have is the Zama C1Q-S45 and this does not have H or L screws...just an idle screw. The Zama TechGuide_2007.pdf states that the mixture screw must be removed before removal of the nozzle. The nozzle is a screw in type (if I recall correctly). So, my question is, can I just remove the nozzle, clean it up and replace it with no problem? Or, what is the procedure for this? Or, how can I get this back up and running? Thanks!