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greauxpete

Pickup tube

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I traced a fuel issue (air leak)

to my tank by hooking up an electric fuel pump directly to my tank and observing air bubbles in a clear fuel line (no air bubbles when hooked up to an external tank).

 

Anyway, when I removed the pickup tube fitting the tube did not come up with the fitting and appears stuck in the tank.

I was only able to get the screen and fitting out.

The fittong is threaded on both the OD and ID.

See pictures below.

 

How can I get the tube out of the tank?

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Called the tank manufacturer (RDS)and he pulled up the dwg (nice guy named Ray).

 

Apparently, the aluminum tube I'm seeing in the pics is not the pickup tube but, is a "guide tube" and is angled towards the rear of the tank. The plastic pickup tube is inserted into the "guide tube" and threaded to the coupling on the tank.

 

My pickup tube appears to have deteriorated and is probably either laying on the tank bottom or stuck in the guide tube. I tried to retrieve the plastic pickup tube with a long pick, but all i was able to get were small plastic flakes. I am not sure how I was getting any fuel with the plastic pickup tube gone. I guess the guide tube was closed in enough to generate some suction.

 

Fortunately, I have a spare threaded inlet on my tank. RDS recommended I use the spare and plug off the other.

 

RDS offered to sell me a pickup tube for my tank cut to the right length. I will take them up if it is ethanol approved.

 

I have attached pics of the tank nameplate.

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I fought the same battle a few years ago. Ended up using the second pickup, and worked fine. One other time I had a piece of gasket material get pulled into the tube, causing a fuel restriction only at full throttle. Used a piece of stainless wire to fish it out.

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Dan,

 

So, the information on the aluminum tubes in the tank being "guide tubes" seems correct in your estimation?

Also, what brand pick up tube did you order? (I assume you replaced yours with a plastic pickup tube)

I want to make sure I get the correct plastic to resist ethanol.

 

Thanks for the help,

 

Steve

Edited by greauxpete

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Update:

 

Ordered the pickup tube for my tank.

According to RDS, the pickup tube is 47" long!

 

It needs to get from the center of the rank to the rear-bottom.

 

Will post pics when I receive it.

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The pickup tubes on mine were not corroded and did not have a plastic liner. I wonder if that was something US Marine specd out for their tanks. Makes me wonder if there may have been a quality control issue where the pickup tube was welded to the top of the tank and small holes were allowing air to be drawn into the fuel line on some tanks.

 

The two things Mr Robalo pointed out when I had my tank issues years ago was an occasional problem with the check valve in the pickup tube and the internal screen getting plugged and restricting fuel flow. When I had the problem the first time with fuel flow, the screen was full of trash. I removed both the screen and check valve in both pickups and decided to let the fuel / water separator catch any trash. Only other time I had a problem was 2 years ago when part of an old fuel sender gasket got pulled into the pickup tube and lodged at the top where the 90 degree fitting exits the tank.

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I received my pickup tube from RDS, it does not fit.... The ID of my "guide tube"is only 0.35". The OD of the pickup tube is 0.51". Also the connection to the top of the my tank is 0.375" NPT, the connection on the top of the pickup tube they sent me is 0.5" NPT.also, too big..

 

Starting to wonder if the "guide tubes" are actually pickup tubes since there is a removeable screen on the top of the aluminum guide tubes in the tank. See pic below. They are sending me another pickup tube, but the OD of the tube will need to be 5/16" to fit on the tank guide tubes.

RDS said "I'm on my own", after he sends this pickup tube

 

Not sure what to do at this point..

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Edited by greauxpete

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My bet is it is a pickup tube. Any chance what appears to be a plastic liner is corrosion inside the tube? It just doesn't make sense to put a liner in a perfectly good tube, I would think. As for suggestions on what to do...try something like a bottle brush set-up to run down the tube to clear out the crud. Maybe even a piece of stainless or piano wire with a cleaning swab to push down the tube. Just need to be careful it does not come off in the tube, creating another issue.

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Dan, it could be dried fuel, corrosion, etc. I'm going to hook up to the spare fuel inlet (and plug the old one), with no pickup tube and run my clear hose and see if it's still sucking air. If it is, I'll need a pickup tube inside the pipe. The other inlet must be allowing air through a pinhole or crack.

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Update:

 

 

I switched over to the spare fuel outlet on the tank and everything is running great!

 

Lessons learned about my tank:

 

There is no "guide tube" and/or seperate plastic pickup tube on this tank. The aluminum pipe IS the pickup tube.

If the aluminum pick up tube pipe develops a crack, game over.. I was fortunate, in that the tank had a spare outlet for twin outboards.

 

Not sure what I'll do if the spare pickup tube cracks? I guess I'll have to fabricate a pickup tube and try to snake it along the side of the tank baffles to get it to the rear of the tank. I'll worry about that when it happens.

 

Dan, thanks for the help..

 

Steve

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After this last trip, my engine started giving me issues at rpms approaching 5000 rpm. Next step is to run on an external tank and if it still shows an issue replace the fuel pump. If there is no issue on the external tank, I'm going to have to figure out how to snake a pickup tube into one of the existing pickup fittings by drilling out the pipe with an air angle drill.

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Update: ran great on external tank.

Cutting a hatch in the floor at the rear of tank and adding a sending unit flange with a larger plastic pickup tube.

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Any possibility the vent line is plugged?

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There is no change in petformance when I remove the gas cap. Is that a valid test?

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Yup...if there was a vacuum in the tank due to clogged vent, that would have eliminated it.

 

So both pickup tubes are resulting in the same issue; lack of power above 5,000 rpms. Running off remote tank, issue does not exist. Can you disconnect the fuel line at the fuel tank and plumb it into the remote tank? Just want to make sure if the problem is at the tank or between the tank and motor (either fuel line or external fuel filter, if you have one installed).

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Dan,the old pickup tube (tube #1) was much worse (had significant surging). Switching to pickup tube #2 was much better but, lacked power getting out of the hole and above 4800 rpm.switching to the external tank eliminated the problem completely.

 

I did not hook up the external tank to the filter separator (I should have to rule out my fuel separator and floscan).

 

Thanks,

 

Steve

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Here are some pics from my pickup tube install. The rear of the fuel tank ended up being directly under the center of the live well (no access), so we cut an access hole right in front of the console but,where no one stands under the cover.

 

All I need to do is seal the cut edges of the wood with epoxy resin and seal and screw down the TH marine screw down hatch cover with 4200.

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Edited by greauxpete

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Plan looks good so far! I hope this takes care of the fuel starvation issue.

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Installed, edges sealed with west gflex epoxy...

 

Waiting for this hurricane to move north so I can go run it..

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Edited by greauxpete

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Hope you fair better than just west of ya!

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Thanks, thankfully not bad over here.

 

Texas is getting pounded, 50 inches of rain over 2-3 days is unmanageable. I've never seen a major hurricane stall out like this. It needs to move north.

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FYI, 1995 2320 tank dimensions as per RDS:

(This may help someone later)

 

L = 65"

 

W = 32.5"

 

H = 14"

 

Thickness = 0.125"

 

Baffle is located 27" from Rear of tank (there are 45 degree cutouts on the corners of the baffles)

 

Steve

Edited by greauxpete

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Pulled the floor coffin panel to change the old fuel hoses:

(It was filthy, this was after cleaning it up)

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Edited by greauxpete

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What kind of condition were the old hoses? Any kinks that could have restricted fuel flow?

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Hoses were very stiff and had areas which were balooning and dry rotted. It was time. I ended up testing all my components in line with new pickup tube:

 

Ball: bad, had plastic hose liner particles inside after cleaning it out. Replaced it.

Old hose: bad, see above.

Old pick up tubes: both bad. Replaced as per above.

Filter seperator housing: bad, not sure why but engine surged with new fuel line/pickup tube online with filter. Trashed it for a new racor.

Engine: good on new direct fuel line (only) from new pickup tube.

Floscan fuel flow meter: good in line with new hose/pickup tube.

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