Automatic Bilge Question

[baytripper89]

I have a 1989 Overnighter 20 that I bought used a couple of years ago. Overall it has performed well - this is my 5th season with it. There's one thing that it does that I want to understand better and need to know if it's something that I need to take care of.

If I'm out with a heavy load - couple of big guys in the cockpit - the automatic bilge pump will go on from time to time and pump out some water from the bilge. It will go on for a short time and then stop but will kick on again sometime later. I'm not sure why this happens and if it's something I need to follow up on. It generally doesn't do this with a lighter load only with the heavier load. I'm guessing seems that water is getting into bilge somehow but I'm not clear how / why this happens. Any feedback on this would be appreciated.

 

[seasick]

I have a 1989 Overnighter 20 that I bought used a couple of years ago. Overall it has performed well - this is my 5th season with it. There's one thing that it does that I want to understand better and need to know if it's something that I need to take care of.

If I'm out with a heavy load - couple of big guys in the cockpit - the automatic bilge pump will go on from time to time and pump out some water from the bilge. It will go on for a short time and then stop but will kick on again sometime later. I'm not sure why this happens and if it's something I need to follow up on. It generally doesn't do this with a lighter load only with the heavier load. I'm guessing seems that water is getting into bilge somehow but I'm not clear how / why this happens. Any feedback on this would be appreciated.

A few possibilities come to mind:
The first is that there is water leaking because some fitting or screw hole that is normally not under water, now is below the water due to the extra load. The second is that since the rear of the boat may be sitting lower and the front higher, water in the forward bilge is flowing back to the rear bilge. If this is the case, eventually with the heavier load, the bilge pump should stop running or cycling. If is continues to cycle than I would think that the first possibility is more likely.
Of course depending on what you are doing when out with the heavier load, if you have backwash over the motor well, the reason could be bad access plate seals or transom scupper scupper leaks. The outer deck scuppers themselves might be below the water line and you might have a leaky scupper or scupper hose.
It is going to be hard to find any leaks at rest unless you can load up the boat with the same load of your buddies I suggest a few beers and a short dock party before the next outing

 

[Fishtales]

X2 my guess is intrusion via a scupper or lead that is exposed when a large load on board. Invite the fat guys, order the beer and pizza and start looking!

 

[Firenailer]

Maybe check the rubber o rings on the access hatches ( in the motor well and cockpit floor).

With a heavier load you might be getting some motor wash flooding that well and leaking into the bilge back there through the o rings. Anything coming through the scuppers should wash out the same way and shouldn't be getting into the bilge area unless those o ring seals are shot and its leaking through.

Make sure you have the raw water valve shut off if your not using the live well, I think I remember that on older boats that could overflow into the bilge as well.

 

[glacierbaze]

If it is anything like my '93 Tournament 22, it is a function of poor design. The only bilge pump on my boat is in a small boxed in area just in front of the transom, and all the water getting into that box, and to the pump, has to flow through a 3/4 inch pvc pipe in a bulkhead. The pump empties the water faster than it can flow in, so it cycles. Plus, I believe the boat traps water forward somewhere.
I am in the Morehead City, NC area, so because of the hurricane threat this past week, I had raised the front of my trailer tongue to the top of the bumper on my Suburban, with the transom plug out, so that the boat had a very good drainage angle all week. I was sure that I had a dry bilge, but Friday when I put the plug in, and backed down the ramp, the bilge pump cycled 3 times. It always cycles a few times when I back down the ramp.
This may be what is happening when your big buddies stand at the transom for a while, the water runs back to the transon, and cycles the pump.
I intend to put a second pump in somewhere in front of the rear bulkhead. If I hit something, and put even a golf ball sized hole in my boat, it would fill up a lot faster than the water could drain through that 3/4 pvc pipe to the pump.
Another good reason to have a portable back-up pump rigged and ready to go.

 

[suzukidave]

i like the theory that you are draining water out of the forward bulkheads because the boat is handling differently.

 

[baytripper89]

Thanks for all the suggestions. You've given me some ideas to follow up on. Much appreciated.