String Trimmer Not Running in Anything Besides Choke

[jcsjourney2008]

I have a Ryobi CS30 (RY30530). It was produced in 2008 and has always been a good trimmer, until it started acting up. My problem is exactly as follows:
Step 1 - Put the trimmer in "Start Mode" or "Choke" and press primer bulb any number of times.
Step 2 - Pull the Starter 3 times and it starts up nicely, but the engine does not sound right
Here is where the problems start.
- When i do to take the trimmer out of "choke" by pressing the throttle, the engine will cut off. This happens when I tap the throttle and get the trimmer into idle.
- When i take the trimmer from idle and into full throttle, it will run at the same speed even though the engine should have doubled speed.
- If i then let go of the throttle and quickly go back into full throttle, it will not speed up, it will half its speed and then shut off after a repeat
- If i take it and try to use the trimmer in "choke", then the engine will slow down, both engine and trimmer thread, with each blade of grass i cut.
- If i try to start the trimmer in anything besides choke, the engine will not start
-There are the occasional times where i will hear a very high pitched sound as you walk away from the trimmer that sounds as it is going to explode

Here are the service repairs in the life of the machine:
- Replaced Fuel Line (Yesterday)
- Replaced Primer Bulb (Yesterday)
- Replaced Fuel with a brand new mix and new gas (Yesterday)
- Replaced Spark Plug (Yesterday)

Things i have tried to fix the Problem:
- Cleaned entire carburetor and looked for any obstructions
- Replaced parts above
- Changed idle screw in all possible positions
- Tried the trimmer with and without the fuel line filter

This trimmer may have about 200 hours at most on it. I would love to figure this out, so all suggestions are appreciated! Please help!

 

[DaveTN]

When a 2 cycle weedeater, chainsaw, blower etc. will not "throttle up" as it should, similar to a motorcycle revving up out of gear at an intersection before he puts it in gear. What the problem usually turns out to be is the "L" (Low Side) is not turned counter-clockwise enough and thus not letting in enough fuel to let the engine rev up. Turn the "L" screw about 1/8" turn counter-clockwise and see if that helps it. When an engine won't run full throttle and hit the highest RPM, it's in the "H" (High Side) and try either turning it a little (1/8 turn counter and see if it helps. If not, go clockwise and see if that helps) When you hit maximum RPM, then leave it alone. Go back to the "L" and check to see if it will rev up. If it stumbles and hesitates then turn it counter about 1/16" turn and then try to throttle it up. If it helps, then go another 1/16" inch turn. Once it throttles up fine, then leave it alone.