If you have no freeplay at all, try loosening the tension on the cable. Too tight will make it slip, because that's like having a certain amount of pull started on it before you pull it.

First - Adjust the cable as shown in the video.....you need some slack in the cable and the "free play" as described and demonstrated with the two nickels.  You can make this adjustment using the adjuster up at the lever on the handlebars.....or if needed with the two nuts at the bottom end of the cable.

Second - then look at the position of the chrome lever down on the engine.  If it is even or higher than the upper mark on the black case, then you need to install a shorter rod inside the clutch.

Ok so I’ve got about two nickel widths on my lever right now but the arm hasn’t moved much it seems.  I’ll have to fire it up and see where it feels like it grabbing