Fuel tank condensation (tank not in use)

[healey8390]

How much water can a fuel tank accumulate? I seem to have A LOT!! I'm doing the floor on my boat right now so I figure let me see how the tank looks.... I've been using external tanks since I bought it about 7+ years ago because it's old (78') and didn't know the history of its use. I'm willing to take a gamble and give it a try now.... It has a hose and primer bulb, I changed the primer bulb and am draining it. So far nothing but crystal clear water has come out, I'm draining it into a small dirt bike tank I had sitting around, I think it's almost two gallons. So far I estimate at least six gallons of clear water has drained. Does this sound normal for at least seven years of non use? From what I've looked up the tank is 30-40 gallons. It's a Wellcraft Airslot 165. Any tips/fyi's appreciated. Thanks!!

 

[Chris1956]

More likely rain water has leaked into the tank. Fuel level senders can and often leak. Look for a place where water can pool on top of the tank.

If tank is steel or aluminum, look for pinholes or worse on the bottom and sides of the tank. Just because it holds 6Gal water, doesn't mean it will hold 40 Gal gasoline.