Issues with less than 4 gallons of fuel in tank

[JOEALLY]

The boat I'm restoring has a mark near the bottom of the tank that says "5".

I'm assuming it's a 5 gallon mark. Well today is the 1st time I've been able to stretch the motor out and really run it.

Here's what went down, be patient with my storytelling :blah blah blah

Launched the boat with about 3" of fuel about that "5" mark. Motor ran perfect for several passes and I"d say at least 15-20 minutes of steady running with a few stops and starts in between. Motor starts "stuttering" or "cutting out" at high rpms, then later at lower rpms too. So, I look around and notice that I"m about 1" below that "5" mark. I don't think anything about it considering there is a few gallons of fuel left.

I go buy new plugs and a new fuel line (needed them anyway), dump 6 gallons of fuel in it and head back to the river. The motor runs perfect, turned a 28 hrydromotive quad iv to 6k and 81+ mph. Had my son with me so didn't trim it out.

Well, I run it for about 15 minutes or so and right before leaving, it starts the same "stuttering" and "cutting out". It's not constant, but very noticeable. So, in looking around I notice that the fuel level was very close to 1" below that "5" mark.

I get home and pull the pick up tube out of the tank and measuring it against the fuel level, the pick up is about an 1" below the fuel level where it was cutting out. No visible cracks or splits in tube.

Is it possible that the fuel is sloshing around even though it's still 1" above the bottom of the pick up tube and starving the motor?

Or is this a weird coincidence and something else is going on?

1991 2.5 Carb 200 Merc / 1990 xb2002

 

[Dave Hensley]

Would it idle? If so I am guessing you are sloshing away from pick up at speed or getting on plane. I would put a longer tube in it with a screen.

 

[LakeAnna]

Like Dave said it should be an easy fix... more fuel and maybe a new longer pickup. My last GS would run out with 3-4 gallons left in the tank before I cut a new tube for it.

 

[JOEALLY]

Yes it would idle. I sent another owner a text and he said the same thing.

I'm thinking about making a pick up out of stainless tubing.

What are some other options for a new pick up tube?

 

[fnshrmaster]

I just made one for mine out of brass.http://www.diamondmarine.com/web_pages/Fuel System.htm. I know your not running a pump but if you look at the picture you will see the copper pickup tube, I made one just like it from a piece of soft copper 1/2" and a brass elbow for the top of the tank. Should be an easy fix. Kurt

 

[JOEALLY]

Thanks guys

 

[Bobalouie]

Get a thru tank fitting from Jegs or Summit and put a bung in the bottom of your tank. Thats what I did.

 

[2fast4mom]

On most of the Ally tanks that I've had the pleasure (LOL) to remove, there is a recessed "sump" in the tank bottom center that is designed to avoid what you're describing.

The pickup tube should go down into that downward, recessed area that I'm guessing holds about 1/2 gallon of gas.

 

[suicidealli]

I make my own pick up too. I use soft copper and put a bend tord the back of the tank and the end of it. Replace the fitting on top of the tank with brass. Solder the together. Mine doesn't leave much in the tank.

Roy