Fuel tank troubles.

[MossyOak99]

I have a 87 Larson with a 120 mercruiser in it. I have been doing a lot of work on it in the past year or so. I have been trying to get it ready to put in the water and I am having problems.
I had the engine out of the boat and reinstalled it a few weeks ago then got it aligned before putting the outdrive back on. Everything seemed to be going very smoothly and was anticipating getting it into the water. But the world of boating came to a halt.
I am not getting fuel to the fuel pump. I have determined that it must be something in the fuel tank. When i hook up a different tank to the fuel pump it will start right and run like a champ. However there is no fuel coming from the built-in tank. I have over a half of tank in the boat that was just put in two weeks ago. I have read about checking the fuel pickup line and the anti-siphon valve. But the problem is that everything is welded directly to the tank. There is nothing that can be removed aside from the sending unit. how do i go about checking these items. I wish I would have tested the motor before getting the floor put back in because I will need to cut a hole to get at the pickup side of the tank. So before I go cutting into the floor any help with determining why there's no fuel would be gretaly appreciated.

 

[JustJason]

Re: Fuel tank troubles.

your not getting fuel because your sucking air.... you can splice in a piece of clear vynil line in front of the fuel pump to veryify that.
after you verify it you gotta figure out where your getting air from....
just for giggles.... do you see a fuel shutoff valve coming out of the tank anywhere?

 

[Don S]

Re: Fuel tank troubles.

You could also have a plugged pickup tube or anti-siphon valve. This would also prevent fuel from getting to the pump.

 

[MossyOak99]

Re: Fuel tank troubles.

There isn't a fuel shut-off on the tank. I had it out while I redid the floor. Cleaned it up real well and then put it back before laying the floor. There is no fuel in the line at all which is also new. Do I need to siphon the fuel through the line to get the fuel started or will the pump be able to pull it all the way through. I have run a clear line in with the fuel line and got no fuel through it. But it i funnel fuel into the line first the pump will pull that fuel through. How do I check the pick-up or anti-syphon valve when everything is welded to the tank?

 

[chiefalen]

Re: Fuel tank troubles.

Tack welded? Should be able to hit them with a hammer or angle grind off them welds. What stupid ----- would weld that. First time I heard that.

You can pump out all that fuel with a cheap automotive fuel pump. From the hole where the sending unit is. Took me 1/2 hour 30 gallons when I did my tank.

I used my shop vac blower with a double hose so the can was in the cuddy about 6 feet away from the hole no sparks, I blew air in the tank all night to dry it out.

Next day I took all the fittings and hoses off. Vent hose too. Check em all take nothing for granted.

 

[JustJason]

Re: Fuel tank troubles.

every fitting i know of is plastic brass or aluminum.... and your saying somebody welded that????

 

[Don S]

Re: Fuel tank troubles.

On many tanks, there is a thicker piece of aluminum welded to the top of the tank so it can be threaded for the pickup tube. Then the pickup tube is cut to length and threaded in. I'm fairly sure he doesn't understand what he's looking at.
Pictures would be a large plus in this instance.

 

[MossyOak99]

Re: Fuel tank troubles.

I apologize for the improper assessment of the problem. Don was right about it being a piece welded to the tank for the pick-up to thread into. I cut the hole in the floor today to inspect. I was going off my memory from installing the tank. First off someone removed the anti-siphon valve and replaced with a regular one so that wasn't the issue. Then I dove deeper. Went to pull out the pick-up tube to inspect it and found that there wasn't one there. That definitely would be why there is no fuel coming from the tank. Then I found out that you cannot get those anywhere. So I am going to make my own pick-up tube out of brass piping. My question is what should I use for the screening/filter at the bottom?

 

[chiefalen]

Re: Fuel tank troubles.

Now you know why you should have left a access. Alot of places sell the pickup tube with screen attached. However aluminum, is a better choice any napa or auto store has brake tube. You need a tight screen hmmm napa might have that also. You must install a ant-syphon valve it's the law and for your safety.

 

[MossyOak99]

Re: Fuel tank troubles.

I already bought a new anti-siphon valve. Did that right away. I don't want this boat going up in flames on me. Will any type of pick-up tube work or does it need to be marine specific? No marine shops around here can get one but I didn't try the auto parts store. I was just going to put in a brass pipe long enough for the tank depth. I figured that I wouldn't have any problems with the brass being used. Am I wrong here? Do I need to get an actual pick-up tube? I wish I could just manage to get the darn thing out of the tank and then I could just screw it back on.

 

[chiefalen]

Re: Fuel tank troubles.

Send don a e-mail ask him if he has one. Maybe someone else reads this and has one the real deal. Maybe they can tell you where to get one. Do it right this time right.

 

[MossyOak99]

Re: Fuel tank troubles.

Thanks for your help. I will keep looking into getting the right one.

 

[Don S]

Re: Fuel tank troubles.

iboats carries them. Look at this link. They are out of stock right now, might call and see when they are due.
http://www.iboats.com/Tempo_Withdra...16416498--**********.280101898--view_id.40325

You can also google "Tempo Part # 010270" and see who else might carry it.

 

[MossyOak99]

Re: Fuel tank troubles.

Thanks Don. Hope I can see water soon.

 

[Bondo]

Re: Fuel tank troubles.

So I am going to make my own pick-up tube out of brass piping. My question is what should I use for the screening/filter at the bottom?

Ayuh,....

I built many using Copper Tubing....

3/8" soft Copper Tubing, cut aliitle long,+ soldered into the brass elbow.......
Just don't put the pickup end at the Very bottom point,... That's where the Water lays....

Btw,... No Screen needed.....
If it's Big Crud,... It'll hang up in the Anti-siphon valve,...
Smaller Crud just goes the the Fuel Filter,... Where it belongs.....

 

[MossyOak99]

Re: Fuel tank troubles.

Bond-o thanks for the tip. I have heard others talk about this method. How far from the bottom should I leave it? i was thinking 1/4 to 1/2 inch.

 

[Bondo]

Re: Fuel tank troubles.

i was thinking 1/4 to 1/2 inch.

Ayuh,....

That should work,....
Just try to consider the angle the boats sits,+ runs at,....
The Bottom of the tank, May not be the Bottom,..... Ya Know......

 

[MossyOak99]

Re: Fuel tank troubles.

That's a good point. Gonna try to get that set-up tomorrow and hopefully have it in the water sunday after a few more checks.

 

[MossyOak99]

Re: Fuel tank troubles.

Well I did the copper pipe pick-up tube like Bond-o suggested. It is working great now. Fired up no problem and is running on the muffs great. Will be taking it out on the water tomorrow evening to be sure all works well out there. I don't see any reason why it wouldn't.

 

[JustJason]

Re: Fuel tank troubles.

You found your problem, Good for you! see.... you were sucking air!! I like the use the vynil hose all the time, i have a couple of test jigs made up depending of the size of the fuel line in the boat.
One note for anyone else that reads this post. Don could have been equally as right with having a clog. But if you do use the vynil line, and you have a clog, you'll know right away because what will happen is the vynil line will colapse on itself due to the restriction downstream and the fuel pump trying to suck everything in the line out (ie-the air in the line). if there is no restriction, then the line will stay round.