I Have A Honda Em1800x With A Gx140 Motor That Starts With One Pull! But It Won't Idle Up! It Just Sit's And Putters, But Every Once In A While It Will Start And Run Perfectly!i Checked Everything I Could Think Of!

What do you mean by "Every Once In A While It Will Start And Run Perfectly" --- does it run up sometimes, but not other times?

Also, does this unit feature an "Idle Down" control?

What do you mean by "Every Once In A While It Will Start And Run Perfectly" --- does it run up sometimes, but not other times?

Also, does this unit feature an "Idle Down" control?

yes sometimes it will run with no problem then when i go to start again it will start but only at a slow idle! and no there is no idle down control that i know of!

You've got to do more looking. I suggest test running it numerous times, and on shut-down, observe the governor arm linkage (connects to the carb.) to see what's happening. It should move the carb. to full throttle as the engine coasts down. When you start it up, it should surge toward full RPM and settle into operating RPM without overspeeding, 3600 RPM for a typical (2-pole) gen-set.

That is unless, for some reason a throttle control exists and you're bringing it down to idle before shut-down. Most gen-sets don't have and don't need a functional throttle control.
Paul