rainwater in gas tank, 23" CC

[tinboat]

I own a 1998 23' CC and have been towed in three times after heavy rain storms because of water in the gas. Last season I installed a new O-ring under the fuel cap, but this did not solve the problem. Does anyone have a suggestion abpout how the rain is getting into the gas?

[oldbluesplayer]

Well, I'm not sure how it's getting in, but it should only have two choices - fill and vent - so double check that cap - even with the new o-ring it might not be seating right, also check your vent - it's not angled up, is it ? Is the vent line lying in the bilge, in water, when it rains? if that was the case, and it had a crack, it could let water into the tank.

My next thought is that it sounds like you don't have a water seperating fuel filter, and probably ought to install one.

Another thought, is the new E-10 gas - from what I've read on this stuff, it hold much more water in suspension, than the old gas, but when the limit is exceeded, it dumps it all out of suspension - how much do you use the boat? how long between fill-ups, how long between those three times you got towed in ?

just random thoughts

Bill

[CHANCE1234]

maybe its bilge water splashing around and getting up on top of the tank and through the sending unit.

[tinboat]

Yes, I have a fuel/water filter, and I drain it before each use. However, the large amount of water in the gas simply overwhelmed it as well as the filter on my Yamaha 225.

[Capt Chuck]

Tinboat

If water is not getting in thru the vent or fuel lines as you have stated, then it sounds as thou water is "ponding" on top of the tank (low spot). How it gets there only you can make that discovery.

Next step would be to find where the "ponding" water is entering the tank. Either it is at the gas float switch seal or more likely it is at the back of the tank. Now let me explain: [img]/forum/images/graemlins/tongue.gif[/img]
During the original tank install, some of the foam has extended over the top of the tank forming a back wall or a containment type area. When your boat is at rest or up on plane, water is settling (since 1998 - 8 years!) in that area and finaly the fresh water has created a hole that has corroded thru your tank. Now all water "ponding" or gathering on top of the tank is mixing into your fuel.
Try lifting the tank deck cover off to find your problem

Good Luck and let us know the outcome ?

[tinboat]

Thanks, Capt. Chuck, for a well pondered answer! I'll investigate.