Fuel problem

I have a 1985 29' Silverton Sport Cruiser with twin Crusader inboards. 2 fuel tanks on either side both 75 gallons.

I recently purchased this vessel and I ended up filling the port tank with fuel, and I thought there was more in the starboard however i was wrong. Anyway while underway today both engines shut down. Long story short, the starboard tank was ran dry but my port tank still has a full 75 gallons. (this explains my listing to the port side)

Anyway, for some reason fuel is NOT being pulled from the port tank and I cannot seem to figure out where I should start looking. Both engines are getting fuel no problem from the starboard tank so I wouldnt think it was a fuel filter.

I'm not 100% sure how fuel pumps work but I would again assume if both engines are getting fuel a pump wouldnt be the problem but I could be wrong. I looked at all the fuel lines and I do not see anything that sticks out. I'm really hoping it wouldn't be something inside the tank or something I would have to pull that tank for but maybe someone has had a similar problem and can point me in a troubleshooting direction.

thanks!

-Justin

I'd say you are right in that if both engines were running, a fuel pump isn't your problem.

I'd suggest taking a day or so and get familiar with your boat's systems. Sounds like your fuel system is the first place to start. You most likely have some sort of crossover configuration, where either tank can feed either engine. I'd bet the valve(s) are set so the starboard tank feeds both engines. Some may have shutoff valves and TEEs and others have three-way valves. I'd make a diagram. Follow the tank feed towards the engine. Shouldn't be too hard to find all the parts.

Sounds logical. There are three valves that I can access with relative ease and they are all open. They are in the copper line between some water separaters. If they are all open I don't see why it wouldn't draw from the port tank also. I did trace all tubes back to these valves and everything looks in order. There has to be something hidden I just can't see.

Not trying to be a smart a## but you did shut the valve off to the starbord tank after she ran dry? My boat also has twin tanks and it will draw more from the starbord tank then the port if both are on as well. If yours has drained the one side it may be a case of she is sucking air rather then fuel if the valve is left open.

If either fuel pump is sucking air from an empty tank, both engines will die (as you discovered).

The way to run sucn a setup is to fill both tanks equally, set the valves to let only the port engine pull from the port tank (and etc.) and leave them that way. The crossover valve setup is only for emergencies.

Jeff

PS: In 7 years of running my boat, I have NEVER crossed tanks for any reason.

Hmm, I will try the isolation with the valves. (Dont worry not a smart a$$ comment)... My first time owning a boat with this type of setup.

Forgive me if this sounds novice... but I am . There are 3 valves, I would guess I close the middle one as that would be the crossover part. And in theory this should isolate each tank to each engine.

Guess I will spend some time fiddling with these valves to figure it out. I hope its only something simple like that and nothing major but you never know.

Thanks for the replies!

cheers

Usually the three valves work like this: One to open the tank for the motor on that side, another ditto for the other side, and one that allows fuel to cross over to the other motor. Shut THAT one and open the other two and all will be well.

Yes, the learning curve in boating is steep, but you're on your way up!

Jeff

Ok I'm at boat now I've isolated the tanks to it's respective engine.
The port side is not drawing fuel from starboard just port. But, the fuel line
is completely dry right back to the tank. Yes there is fuel in it lol
approx 65 gallons in it.
Not sure what I could do at this point... Something is perhaps clogged??

<UPDATE>

I left the boat and here are my findings.

1. I ran both engines all valves open. Runs smooth.
2. I closed the crossover valve - Starboard continued to run smooth, port side shutdown
3. opened all valves again, ran both engines, closed port side valve. - Engines continued operation.
4. ran both engines and closed starboard valves - both engines shutdown.
5. ran port engine off starboard tank and ran smoothly - same goes for starboard. This I would assume would rule out a faulty fuel pump on either engine.
6. I disconnected the fuel line at port valve - dry as a bone
7. I disconnected fuel line from fuel tank - dry as a bone

YES there is fuel in the tank. When there is expansion fuel has been dripping from air vent because my boat is listing with all the weight on the port side since no fuel is being used.

I was able to send air through the fuel line after disconnected from port valve and tank with no obstruction.
- So, I'm figuring there is an obstruction somewhere in the tank OR would it be because the boat has sat for 2 years without operation it would need to be I guess primed a bit or vacuumed out?

I'm hoping whatever it is can be corrected without having to pull the tank because that would be pricey

Sounds like a broken pickup tube Internal), a big air leak, or maybe a defective anti-siphon valve. All in the area of the top of the port tank. I hope you have good access.

Well, it's going to be tight for the pickup tubE. I think I have another tight fit for the siphon. I'm swinigng more towards the pickup tube.

On my boat i have 2 100 gallon tanks and when you turn the ignition on you can hear each syphon valve click. My set up has a screw located on the valve that can be turned 90 deg to overide the valve.

On some boats removing the pickup tube can be very expensive. Before deciding to remove the pick up tube there is a simple test you can conduct. Suck on the fuel line. If you get gasoline in your mouth the pick up tube is ok. If you get air, it would indicate the tube has fallen off.

Chuck Hanson

Better yet, remove the anti-siphon valve and blow back through the fitting. If you hear bubbles, it is intact and below the level of the fuel.

Right on Rick!

I'll bet my lunch that your anti-siphon valve is stuck closed. This little ~*@^! is located right where the fuel line comes off the tank. Look for a fitting that appears to be just another piece of plumbing, but inside of it is the nasty little beast that's causing all of your problems.

Jeff

Cheap little part causing all that trouble. I am heading over today and hopefully I can access it. I'm almost sure Ill be working by feel lol. I will let you know how I make out.

Well here it is. The evil anti siphon valve was the culprit. Fuel runs smooth, engine runs great! Thank you to all who responded, hopefully one day I will be able to return the favor!

-Justin

Good man!

Jeff

Glad to hear it was that simple.

Good Job!

Don't forget to make that drawing or at least label the valves. May wanna scketch out the electrical system on the next rainy day, too.

I actually have a good idea of the fuel system now. The electrical system I have a schematic of less of course the extra garbage but I'm working on that also.

I purchased the manual for Crusader engines today so that will more than likely pay for itself over and over again. I'm a little on the stubborn side and certainly don't want to pay a mechanic to troubleshoot and repair things that I could do if I took a little time and effort. Already saved myself a chunk between the fuel issue, an overheating issue and a bad solenoid on my trim tabs.

Thanks again for all the help!

You also learned a ton on how the fuel system works. It was a steep learning curve, but you're way up it now!

Jeff

are the anti-siphon valves pretty standard or manufacturer specific? Seems like this might be a good part(s) to either have an extra on board or proactively change.

No doubt mine are original at 22 years but Trojan is out of business so I'll have to do some digging. As I've found out, they sourced all of their parts from the usual suspects like every other manufacturer.

Bob

I've been running a couple of Tempo ASV for a number of years now. As much as I don't like Tempo stuff, these seem OK. One of them caught some Al swarf from a new fuel tank, but other than that, are fine. Mine go directly to 3/8" Type A hose with a barb fitting. Watch the selection of materials and try to avoid brass on aluminum. Stainless fittings in small pipe sizes are now readily available in the HW stores I frequent.