kohler ch13 surging

I'm having trouble with my kohler command ch13 powered pressure washer. It will only run on choke, and still surges a little even then. I've taken the carb off and cleaned it several times with cleaning brushes, tip cleaners and carb cleaner spray (all after soaking it in gasoline for several hours.
 
I cant get it to even improve, let alone get it to run right. A new carburetor is over $200!! what am i doing wrong??

If it will only run on choke that means your carb is not putting enough gas into the engine. This means you need to make sure your carb is completely clean including all jets and passages. Blow carb cleaner through all passages and jets and make sure it comes out the other end. Run a very fine wire through the jets. DO NOT USE A DRILL BIT. This will make the jet hole bigger and ruin it. Also make sure all gaskets are good between carb and engine.  PS. will it run smooth if you hold the throttle(the butterfly valve closest to the engine) manually or does it die?