SF18 factory 47 gallon fuel tank filling problem

[CaptSeaCraft]

I have to pull the sender out of my SF18 to fill her up.When I try from the gas fill it takesabout 1/3 a gallon then dumps out the breather.Upon reading up on this year model I became aware that this is a larger tank than normal and maybe there is a kink in the filler hose causing the blockage.Does anyone have any info on what I need to do o solve this problem?here's a picture of the foil label that is off the top o the tank.I am happy with the larger capacity.....it would seem that since it was a Ranger boat for most of its life that they must have requested the larger tank and stainless railing etc. when they ordered it.In some ways I feel fortunate for the extras.It would be nice to fill it up regular style though...LOL
Any help would be appreciated.
http://i853.photobucket.com/albums/a...979%20Classic%

[McGillicuddy]

Hey Capt. cool name,
Either someone secretly filled your tank or you need to inspect all three gas veins. Obviously the fill should be the biggest hose. It should have a fairly straight path down the gunwale across the deck to the tank. I'd stick a long, smaller diameter hose in it at the fill tube and see if it has any trouble reaching the gas tank (you know, like when you're trying to get some gas out of your Uncle's truck ). There may be a loop in the fill hose or maybe something got in there, but even so, if it were blocked the fuel would likely back up and flood at the fill hole.

The vent elbow is probably next to the fill elbow, and its hose will run toward the vent - it could have a clog that creates an airlock where maybe a pocket of air is just pushing a bit of trapped gasoline out, or maybe there is just some gas sitting in a low spot that is forced out when any comes in thru the fill. Or maybe a chunk of sealant dissolved or broke free and floated into the vent tube. You might start by disconnecting the vent hose at the tank and see what drains out when you force air back down it from the vent. Have a jug ready to catch the gasoline or whatever. And "no smoking" around you...

Obviously, this could happen on the supply hose between the tank and engine, especially at brass elbows. Check your fuel/water separator to see if you find any crap in there.

Sealants for sending units have changed in chemistry over the years as has fuel. I found chunks of silicone were clogging my fuel lines. Someone probably replaced a sending unit and used silicone for a gasket, and modern gas with ethanol probably broke it down causing me grief. Here is a pic of that:


Look into it now before the fishing really goes off.
Good luck and let us know what you find...

[76Red18]

When i first got mine it would only hold about 25 gallons (37 gallon tank I was told). I finally found out the tank was backwards ;vent and fill were at the rear. The hitch on my truck was set high for my other trailers and therefore held the boat at an angle when fueling up. Pump would shut off but gauge would only read 3/4. I think I was also dumping fuel out the vent on quick accelerations; Not good! Sorry Mother Nature. Pulled the tank, turned it around and it solved the problem. Fill and vent up front, sending unit a third of the way from the back. Since then, I've done away with that tank and shoehorned in a 60 gallon set up the same way.

[SeaPlusPlus]

When i first got mine it would only hold about 25 gallons (37 gallon tank I was told). I finally found out the tank was backwards ;vent and fill were at the rear. The hitch on my truck was set high for my other trailers and therefore held the boat at an angle when fueling up. Pump would shut off but gauge would only read 3/4. I think I was also dumping fuel out the vent on quick accelerations; Not good! Sorry Mother Nature. Pulled the tank, turned it around and it solved the problem. Fill and vent up front, sending unit a third of the way from the back. Since then, I've done away with that tank and shoehorned in a 60 gallon set up the same way.

I have the same problem with my tank in my 20. The fill, vent, and pick up are all on the same side of the tank and it is installed with them in the rear. When it sits on my trailer the front end is higher than the back, so the tank rear fills first and creates an air bubble in the tank so it overflows out the vent.

I considered reversing the tank but with the pickup in the front, there would be a point that momentum from being plane would starve my engine of fuel and stall me.

My solution is when I fill up I bring the stand all the way up (its already in that position when I tow anyways) and then me and a bud lift the boat off the hitch and set it on the ground right behind my truck (easy for me as I don't have much tongue weight with that heavy 4s, though enough that I can't get it to budge by myself). This is enough to make the tank slightly lower in the front, so it fills in the front first and properly vents, allowing me to fill up all the way. Afterwords just lift it right back on hitch as its the air pocket that causes it to overflow and not the angle.

Inconvenient? Yes, but an extra 2 minutes work everytime I fill up is better to me than trying to rip out the tank, and then have someone move the pickup to the rear.

[CaptSeaCraft]

Ok....Time to get to the heart of it.
Thanks to my SeaCraft Bretheren for all the great info.I am coming home today to start removing the t-top,and c.c. to get to the fuel tank under the deck.I'll be doing it all myself since none of my so-called buddies have the time to throw in right now.Whatever...I have done it all myself anyway..would someone call my girlfriend to let her know I'll be REALLY Late for dinner and breakfast!LOL
pics to follow.

[SeaPlusPlus]

Good luck! Lookin forward to pics.

[Old'sCool]

The ethanol is known to eat old lines not rated for ethanol.

[CaptSeaCraft]

Spent the last 5 hours getting to the top of the tank.The fuel fill is in the rear with the sender and pickup and the vent is forward.It would seem that the fill hose was in very bad shape.it took 20 minutes delicately sniping the wire and hose from the fill neck at the tank then I hit wall.I cannot get the large filler line to pull out from the hull between the tank well and the forward gas service.I tried everything.....even pulling the filler line out to give it more room.can there be a hose retainer holding it??I can tell that the filler hose was wasted....definatly kinked at the bend to the tanks filler and below deck forward of the tank well its pulling apart as I try to pull it out.I am geting some good pics. but am worried that I am in trouble.I dont want to have to drill a access hole to see whats up,will have to try again tomorrow.
g'nite

[MakoMike19]

must be something there. post up some pics, i'd like to see what the factory install looked like

[Greno]

I have a place cut out under the gunnel where they cut the liner to replace the filler hose on my tank. You don't know it is there unless you lay on the sole and look.