No it wont fall.
It may not fall, but back in the day, this was a very common area for pitfalls. Be very careful selecting the screws. If too long, they will intrude into the alternator. Also, I would replace each screw one at a time, to ensure that correct orientation of the field coil is maintained.
I’m glad “oldfart” brought this up; I wanted to, but I’m pretty insecure being such a beginner and all.
I was lucky, and a neighbor had a 400/4 generator/coil assembly removed from a bike. I don’t think a more experienced person would need to get in there and see what was going on, but I did.
When I put the finned cover on my generator side, I took out one screw only, and put in a longish (at least 100mm) Allen headed bolt (with the finned cover on it, through the appropriate hole). (I think, on mine anyway, there’s only one hole that will work if you want the fins to go horizontally.) I tightened the bolt until it was finger tight into the coil. I loosened the other two screws, and removed them while I held the coil relatively snuggly against the back of the genny cover with the other hand. (I don’t think it matters a whole lot if the coil does get loose at that point - what matters is that you use the long bolt to snug it into it’s proper place as best you can, before giving the other two bolts the final cinch. I had to kind of jiggle the bolt to get the coil seated properly - I noticed on my friend’s removed one, that inside it has little ridges both at the edge and closer to the middle in kind of a stop sign shape, and they need to line up.) So I put the finned cover in place (along the long bolt obviously) and screwed it down with the other two bolts. Then I took out the long one that had acted as a handle, and put the proper length screw into that one.
I had determined what length to cut the screws with my friend’s removed assembly, with the finned cover I was using. But I don’t think you need to go to that trouble of removing the whole assembly from your bike. Since all three 16 mm, stock screws must be removed in order to get the finned cover in place, you could just do what I did above - to a certain point - just to measure. Long bolt through the proper hole in the finned cover, remove one of the stock screws, thread in the long one (through the proper hole), remove the other two - cinch the whole thing together as tight as you can by hand, and then put a second long bolt in finger tight - back it off two turns, and mark it for length. (You could also probably add a nut before the finned cover on the long “handle” bolt. That way, after removing the last two stock screws, you could tighten the assembly back together tight enough for a good measurement, at least.)
Lastly, one would think you could do this simply by measuring, and maybe you can. But I tried to do that, and couldn’t really get it right. (I don’t think the finned cover sits really precisely into the three holes, and maybe that’s why I failed using measuring and adding.)
I really wanted to be certain I didn’t mess up my genny, and after looking inside of one, I’m glad I made sure what length bolts to use. Although I have used dumb luck successfully in the past, I’m trying to get away from it as a mechanical technique. The bottom line is that you’ve got a window in bolt length of a couple of millimeters, and if you miss that length bad things have an increased likelihood of occurring. If the screws are too short you either can’t get them to grab the coil at all, or they only grab by one or two threads. If they’re too long then you will be unable to tighten the coil to the generator cover properly.
