I recently purchased a 1995 27'...

[Wilks1]

I recently purchased a 1995 27' Sundancer.

I have had an issue twice where it seems to have run out of fuel, even though the gauge showed 1/2 a tank.

Added 10 to 15 gallons. Then cranked to prime carb and she started right up.

The gauge now shows around 3/4 of a tank. My intention is to fill it up and see how many gallons it takes.

According to the gauge that should be around 25-30 gallons. Spec sheet states it has a 100 gallon tank.

At that point I'll know if the gauge is accurate or not.

The other senero is that something has happened to the fuel pick-up tube.

My question is: If I need to access the fuel sending unit - where is it and how do I do that??

[fwebster]

First, try cleaning out the fuel tank vent on the side of the side of the boat. You probably have a dirt dobber's (mud dopper, depednding upon where you live) nest in the opening. When the tank cannot intake enough air thru the vent to equal the volume of fuel you burn, then the fuel pump cannot suck fuel out of the tank and the engine runs out of fuel.

[The_AVA_MARIE]

Look into replacing or adjusting your float actuator in the top of the tank. Most marine actuators are very universal and fit aa variety of tanks. You can activate float by reattaching wires once removed and bend float arm to adjust.

[Wilks1]

vent was clear & I can smell fuel thru it - but to insure it was clean used some brake cleaner & a tooth brush, gently on screen. My next question is "Where is the sending unit & how do I access it?"

[Miller]

Have you changed your fuel filter?

[Big_Ed]

Sounds like your gauge.

[Hugo]

On an older craft, an accurate gas gauge is about as trustworthy as the check is in the mail. Keep a log of your engine running hours and what you think conservatively is your consumption.
Good luck

[SMT]

Could be as simple as a loose or dirty ground. Carefully take both connections off one at a time and clean with wdv40 or electronic cleaner. A voltage reading from the tank sensor on these terminals will determine if the sending is ok. I have also seen the flote on the sensor sitck and not drop. If thats the case remove sensoe for free movement.

[fastred]

It could also be the strainer on the top of the fuel tank. I haad this problem with a Sea Ray Sun Dancer.

[Wilks1]

To fastred, This strainer your referring to where is it located?

[fastred]

The strainer that I am talking is right on top of the fuel tank. Unscrew the fuel line from the fuel tank and you will see a little screen.

[fastred]

It is right on top of the fuel tank. Unscrew the fuel line from the tank and you should finf a little screen . clean the screen and hopefully that will solve your problem.

[Captain_Zero]

If I read correctly you state carburetor. If so you should also check the fuel filter on the carb. You should also check the fuel filter on the fuel cooler if it has one.

[Wilks1]

Update on the fuel situation on my Sundancer.
With a 100 gallon tank & the gauge showing 3/4 I had calculated it would take close to if not at 25 gallons to have the first spit out the vent tube when full...it took 22 gallons.
Thus confirming for me an issue is with the fuel pick-up tube. After consulting with the folks at Miami Marine Tank, the manufacturer of the tank in my boat, they agreed.
As the tube is aluminum and they have seen them over time corrode & break off or develope a crack in the wall of the tube.
As a matter of fact they market a repaitr kit for just this situation.
After consulting with Searay, and once again customer support was outstanding, they provided me the tank number. I called Miami Marine Tank back and they have a kit for my tank. It's a tube that will slide down inside the existing tube, new antislosh valve & elbow. They also told me that there is an additional pickup tube assembly some 16 to 18 inches to port of the one I'm using. This would have been for the port engine had the boat been a twin screw.
At some point I'll add a fuel transfer valve and tap that tube. Just to have a back-up from which to draw fuel. If, hopefully never, the need should ever arise.
Thanks to everyone for their input to my posting.
Ron

[Wilks1]

Fixed it!!! After recieving the new pick up tube. Installation was an issue. New tube wouldn't bend enougn to go down in the tank. Water tank shelf is in the way. Had to drain water tank, disconnect the hoses & lines. Getting the water tank to move was a project. It's double sided taped to the shelf, three rows. Once I got it to move & worked it to port was able to take a hole saw & put a hole in the shelf bottom right above the fuel outlet port.
New pick up tube assembly dropped right in. Now secured fuel line, repositioned water tank back, hooked up all hoses & lines. Given first time at this in cramped quarters it took up my weekend......but it's done & no leaks eather fuel or water...YEA!!