I've put the springs back in pullstarts before. It can be very hard sometimes since the spring loves to pop out as soon as your almost done. If you do try, don't be like me and use safty glasses, cut my cheek when I was a kid. It's been a long time so it's fuzzy in my mind on what I did exactly. If you can get the spring back inside the case you might need something thin and strong to hold up to the open side to keep the spring in. I remember doing it without useing anything but my fingers and needle nose pliers to hook the spring in. I'm not sure how much they have changed in the past 10 years, but it can't be to much different. To get the center piece to slide into place, you'll have to pull the cord lightly to get it to line up. From there it's just luck.

I've even done this with broken springs, close to the end. This is only a quick fix and it could fail on the first pull, or after a few tanks. It's really just to hold you over untill you can get a new one.

Your tune might be out, or the plug is going for your idle/startup problem.

I would get a new battery holder if you don't have a failsafe before your next run. Sometimes your LHS might have a worker with a extra one they will give you if they are nice enough, most upgrade to hump packs making the OEM worthless.

Good luck, hope this helps.