Riddle me this
 

I have a 97 180 Shabah LE and according to the brochure it came with a 30gal fuel tank.

From completely empty to spewing out the fuel filler mine will only hold 15gal. Did I miss something somewhere?





Also mine came with the Volvo Penta 4.3 but all thats referenced in all the material I've read is the Merc 4.3 as being standard. No mention of the Volvo anywhere. What would be the reason for opting for the Volvo over the Merc? Why would Mariah offer to different motors that have basically the same exact specs?

Re: Riddle me this
 

Mariah may have provided an engine in that boat that the customer who bought it new wanted. Not everyone is a Mercruiser fan....

My boat fills differently when its sitting on a trailer (will fill right up) and when sitting on the water (will only fill part way) but to be honest i've never investigated what causes this problem. I would assume that it involves the angle the boat/tank sit at when in the water (ass end down, bow up) that causes air to be trapped in the tank. I did park my behind on the bow of the boat once while filling at a marina & it did seem to make a difference.

Re: Riddle me this
 

I only fill my tank when it's on the trailer simply because the gas on shore is cheaper than it is at the marina.

I also understand the whole air bubble thing but were talking about half a tank of gas here 15gal of space. That is rediculous. Gas tanks are vented for a reason, air and vapor expansion being one of them. At 15 gallons I have gas coming out the vent. Just doesn't make sense if my boat is supposed to have a 30gal tank.

Re: Riddle me this
 

your sending unit is not accurate. how do you know you are completely empty. If it makes you feel better $100 is a 1/4 tank for me but the gauge says full and goes to half in 2 hours.

Re: Riddle me this
 

Anybody know where the sending unit is and how I can check it?

Thanks

Re: Riddle me this
 

I know first hand EXACTLY how many gallons ours holds. Ran it out, dry, caput, nada......EMPTY...... this summer. Just a few hundred yards from the marina/fuel dock. they towed me in and sure enough 125+ gallons later, I was full again.

Not only did it hurt my feelings doing so, my wallet felt the pain even worse at $5.49/gal. The attendant was wondering if we had a leak and would often look around the boat towards the end looking for the oil slick or bilge to turn on. Finally I asked him what he was looking at. He told me, so I turned on the bilge and she spit out a couple gallons of water.

Re: Riddle me this
 

Then it sounds like you have a problem & we're here to try & help you resolve it. Have you checked to see if your vent line is blocked? As for your sending unit just follow the gas filler line down to your fuel tank & you should see a small flap in the carpet just in front of the engine. Lift the flap & you should see your sending unit. I'm not sure that is the cause of the problem but there are a few members here (like Hudson River Steve) that understand the electronics better than i do.

Re: Riddle me this
 

Im going to be doing some work on the boat tomorrow so I'll give the vent line a look and see if I can find the sending unit.

Thanks guys

Re: Riddle me this
 

The fuel sender is located on the top of the fuel tank. From the outside it looks like a round disk with screws or bolts that affix it to the tank. There is a single wire in the center of the disc that sends a resistive signal to the fuel gage. There should also be a second wire that grounds the tank.

Re: Riddle me this
 

I had this problem as well with my 182 Shabah.. I was at a gas station, my tow vehicle and boat were on an incline facing uphill, the fuel gauge prior to this had show a little over half a tank, all I could get in was 3 gallons, then each time I tried to add more no matter how slowly fuel will come up the fill neck and pour out the tank vent all over the swim deck.. I gave up, turned the truck and trailer around to point down hill at a different pump and it took another 9 gallons.

Re: Riddle me this
 

Mine will show nearly empty and 15 gallons will take the gauge to full. I believe mine holds 27 gallons.

Due to no gas docks being open one May morming at the Lake of the Ozarks, I found out that I can go way past empty on my boat and still have gas.

I don't make a habit of it.

Re: Riddle me this
 

Sounds like me and you have the same issue. Let me know if you ever figure out what the problem is.

Re: Riddle me this
 

I'm not sure of the shape or position of your tank but my guess is that it is probably rectangular in shape and the vent tube is probably in the top rear of the tank. When the boat is sitting in the water and the bow is higher than the stern, the vent tube is probably covered by fuel when the fuel level is only partially full. The air trapped in the front of the tank prevents it from filling completely. If there is a threaded bung in the top front of the tank you may want to move the location of the vent to this spot
As far as the gage showing Empty when the tank still has fuel, all fuel systems are designed to do this. The question is; how much un-gagable fuel remains when the gage reads empty? The only way to know for sure is to completely empty the tank via the fuel pick up tube and note the position of the needle on the fuel gage with a piece of tape on the face of the gage when no more fuel can be withdrawn...this is true Empty.

Re: Riddle me this
 

I think the bottom line is these gauges aren't that accurate, all they can do is give you a rough idea of how much fuel you have.
I believe you can go way past empty in our boats, but I'm not going to chance it.