I have a new-to-me Avy C4 I got last week and put it in the water for the first time yesterday. I noticed that the bilge bump kept coming on every 20 minutes or so, shooting out the same amount of water each time (20-30 seconds). We parked the boat on the water and sat for about an hour and I turned the pump on again, shot out the same amount of water. Waited about 10 more minutes, then turned it on again and it shot out the same amount yet again. I checked the plug under the back seat every 30 mins or so, and it seemed to have the same amount of water in it constantly and didn't appear to fluctuate.
The previous owner said he only had the issue when he had his ballast bags full, something about that type of bag having a coupling leak that needed to be fixed on the bag I believe. I didn't fill the bags up the entire time we were on it though, so I don't think that is the issue.
I have seen some post about the shaft packing on other boats possibly being the culprit, but I couldn't find anything on this particular model. Any help or tips you guys could post would be greatly appreciated.