Not sure which fasteners you are referring to. Note: on my last post I said that I purchased a longer cable.  After thinking about it, I remember that I bought the longer cable because I cut the one that came with the kit too short.

Sorry I have been so long with the pictures. After looking at them, I realized that they need a lot of explanation to make sense. Actually, I just followed the instructions that came with the kit.

One area that needs particular attention is the moving of the starter control set on the left handle bar.  It must be moved 3/4" inch inward to allow the thumb throttle to mount next to the rubber hand grip. The clamshell starter group has a tab that sits in a hole on the handlebar to keep it from rotating.  I removed the starter group and drilled a new hole in the handlebar 3/4" inward.  See the attached pictures.

Also, I wanted the cable to be tight against the handlebar all the way from the left to the right side.  I was afraid I might be going through some brush or low hanging limbs and something catch the cable and pull on it.  The result would be a sudden acceleration which could be bad.  So I purchased a new, longer cable online that I could zip tie tight to the handlebars.

I have some installation pictures. I'll work on some explanations and post them in a day or two.

I have just installed a left side trigger throttle to ease my right hand thumb fatigue problem. It is a Goldfinger for Yamaha.

I have the same problem.  Sometimes it grinds going into low and sometimes I have to jiggle the handle to get it to go in.  A few times it popped out of low gear. I only have about 20 hours on mine.