You definitely need a new spring for the plunger. I had the same issue when I first got my CBW. A new plunger spring fixed the issue right up. The long spring in front not the little one outside the machine although it wouldn't hurt replacing that spring also. As far as the multi-ball feature, it definitely sounds like a switch issue, but I am not 100% sure. Also replacing the tip on the plunger is a good idea.