That spring looks really wound up to me. You aren't able to wind that spring all the way around the shaft when installing it are you? Probably impossible. It should do the job of returning the kick start just being brought back enough to get it in the last hole it needs to get in. No extra winding. Just a thought
Here is some shade tree engineering thinking. If the kick stroke is shortened does the spring stay in place? You could move the kick start further back on the splines to reduce your typical kick stroke a little. that may be on the borderline of being ridiculous though.
I know the feeling of tossing something out I didn't think I'd need anymore. Not a pleasant one.
So a bit more on this. I turned back the kickstart lever about 30degrees. That has shortened its throw, and seems that the spring is staying retained. I have in the meantime ordered a replacement spring from Baxter's Cycle, and I'm hoping this would be the cure. I'm also using a later Commando Kick arm, not the straight up and down style that was on these early AMC boxes. So my logic that the commando arm has a bit more rotation to it, and Maybe that's why it's popping out.
As for the winding of the spring, I'm now thinking of something else. When I align this, before I set the spring into the case for tension, where should the hole in the shaft be? At present, the hole in the shaft is in the 12 o'clock position, or facing straight up. This means I am bending this spring back a good bit to fit the tang into the case hole.
Rewatching the Hemmings video now, I seems the spring hole on the shaft he's assembling is at about the 9 - 10 o'clock position. This would put a lot less tension on this spring, and maybe that what I need to try.
I'm just confused, because I feel like I'm doing this with the kick plunger spring fully depressed and loaded onto the pawl, just like he does in the video.
This will be one more thing to check in the morning. Good news is, I feel like I can now strip and reassemble a gearbox in about 25mins time. Just need to it work, then that'll be a good claim.