I have a raw fuel in the bildge. The size of 2 quarters. I checked all the cool fuel and no signs of
leaking I felt the back of the middle port stringer and it’s wet with a fuel smell. Is it possible for the tanks to rupture and leak fuel inside the stringer to the bildge. I popped the access cover for the sending unit tank access and ZERO fuel smell.

boats a 98 35

is it efi? if it is I would put a fuel gage on the rail and turn the ignition on and watch the gage and see if it drops,the other thing you can do is put a bottle of oil dye in your tank and run the boat,then you can check with a black light for traces of fuel.

correct it’s efi. I havnt tested the fuel rail yet but doesn’t seem like much is on the backside other than the line from the cool fuel to the rail

What engines ?? might help

502 Mag MPI with cool fuel setup. non VST

It could be an injector O ring failure, there are 2 per injector, 1 on top at the rail and the second 1 in the intake manifold, check the back of the block for fuel

I checked under the manifold and couldn’t see anything. I need to get the rail checked for pressure. If the orings do fail do they drain out of the back around the block?

I have known of a few 35s that needed fuel tanks mine included. I don’t know if it’s a coincidence or not but they all were leaking on the port side. Mine would only leak when full. We took a blow gun and put air in the vent and you could see gas bubble up thru the foam around the tank when looking down thru the access holes where the sending units are. Hopefully that’s not your problem.

how did you fix it? Any pictures?

did the access port smell ? Mine has zero odor. What did you pay to have the. Floor cut out and tank replaced