Rinse fuel tank compartment?

[Punch53]

As far as I recall the fuel tank compartment on the Grady's were only isolated on the I/O models.

 

[Hookup1]

As far as I recall the fuel tank compartment on the Grady's were only isolated on the I/O models.

I have tried for a while to resolve this issue. I spoke to GW CS (they sent layout diagram) and several GG members. Lots of guesses but no one knew for sure. When I went to replace my fuel tanks last Summer I decided to 100% figure this our at least for my model which is likely the same for all the GW boats built around then.

Read my fuel tank replacement post. Look at the plumbing diagram and images. Front bilge is connected directly to aft bilge and can and was plugged off on my boat. Fuel compartment is isolated and not connect to forward bilge, forward compartment drains into aft compartment which drains into aft bilge - can be closed off but was open on my boat - so fuel compartments drain into aft bilge.



There was a lot of factory debris in the bilge that got cleaned out when the tanks were out. He probably has that plugging up the fitting. My advice would be to pull the deck hatch to expose the aft tank. Take a piece of 3/4" id vinyl hose, work it to he aft end of the tank from the side and use a shop vac to drain. Then take a endoscope camera and get a look at the drain from inside the tank compartment. Insert a screwdriver from the bilge side and try to unblock it. I know it can be done. While putting my tank back in I dropped a few screws that I didn't want to leave down there. I found them and got them out.

 

[JeffN]

My '83 Kingfish IO had a drain from the forward bildge in addition to a short drain from the tank area thru the aft bulkhead into the engine compartment. The drain from the tank area had a plug. When I repowered in '07 the yard removed the drain from the tank area and left and inverted "U" in the aft bulkhead to drain. I was always taught to open the engine hatch and sniff prior to starting. Perhaps they were getting too many corroded fuel tanks, or standards changed. My boat was 3 yeas old when I purchased it. Soon after I purchased it I removed the plug, lots of water came out. After I made a habit of draining on a regular basis. Never got that much water out again.

 

[Hookup1]

GW doesn't recommend closing off the fuel compartment. Neither did my tank builder - let it drain. Otherwise the water has nowhere to go. But a leaking fuel tank will put fuel in the aft bilge.

Forward bilge is closed off. Some members didn't like that but the 1/2" PVC that connects the two is not going to save the boat if one of the pump fails. Given the way the boats sit in the water and how much fuel you have, the water in aft bilge (and any leaking fuel) would wind up under the cabin area creating a bigger hazard. In storage I pull the plug but put it back for the season in the water.

 

[Sardinia306Canyon]

Also, if this line was plugged, how would you know if the tank is leaking? It's a sealed compartment.

You will smell it

I don't suggest you to put a plug in there, if there is not then GW had a reason to not install one.
When i pulled the fuel tank on my RIB fuel tank was in a gelcoatet compartment and there was a drain hole to the bilge on the end too.

If you have whatever leak (including fuel) it would fill a sealed fuel tank compartment and the fuel tank would start to float sooner or later. Also a fuel tank sitting in water don't last very long, so a drain hole is needed to drain any liquid from the fuel tank compartment (aka fuel tank coffin). Thats also why the fuel tank has to sit on PVC strips, to allow water to drain and then dry under the fuel tank.

There are some boats with glassed in fuel tanks and in theory they should sit in a watertight compartment what should make fuel tanks living much longer. However this system does not always work as supposed and if the fuel tank has y leak then owner has to cut the deck to replace the fuel tank.
My Venture 34 had glassed in fuel tanks installed in 99 and there was no lea, but there was a limber hole, but in my case dry.

Chris

 

[Ky Grady]

I had copied this from another post,,,

 

[Toothpick 10]

Did you ever get an answer from Grady?
I can’t figure out how to reach into the stern bilge to see if my fuel coffin is plugged, but there’s no water draining out from it, and my tank is floating!

They got back to and indicated that there was a drain port, and I done subsequent rinsing with the bow nose up on a trailer, and the water does drain out the rear.