Throttle will not stay put above idle

[RTJ49]

My ZD323 throttle will not stay put as it did when new. Anyone have pictures of the throttle mechanism? Is it two springs opposing each other? I see none of the disc type that adjust to put pressure/drag on the cable. Thanks for any help. RTJ49

 

[RjCorazza]

It appears to be a friction bolt and washers on the handle base.

 

[Brown Dog]

I have to tighten up my ZD1511 2r2 times per summer.
13mm best I remember.

 

[GreenDuramax04]

The springs are only for cable tension. As stated by RJ the throttle is held by friction nuts and washers. There should be two nuts. One locks the other. Doesnt need much tightening to get your desired friction.