Fuel Tank/Pick-Up Tube Question

[Kmort]

I'm trying to resolve an apparent fuel system issue with my 1995 4.3L Mercruiser engine and when trying to remove the pick-up line from the built in 30 gallon plastic fuel tank, I was unable to pull it completely out. I only un-screwed the coupler that the fuel line attaches. There is another large flat (washer like) hexed nut left attached to the plastic tank. Question is.... Can it be removed so I can get the tube out? OR will I mess up the whole assembly?

 

[Bondo]

Re: Fuel Tank/Pick-Up Tube Question

Ayuh,.... Got a picture,..??

Generally speakin', I'd assume there should be an elbow that'll screw outa the fitting that is permanently attached to the plastic...

 

[Kmort]

Re: Fuel Tank/Pick-Up Tube Question

That is what I unscrewed, but the tube will not pass the fitting. I don't have a picture at the moment, but will get one next week.

 

[Mak Daugherty]

Re: Fuel Tank/Pick-Up Tube Question

I'm actually investigating a apparent fuel issue also (low RPM - WOT). I did the same thing taking it one step further. I unscrewed the big hex nut. It's attached to a threaded metal tube that pokes thru the top of the plastic tank. I'm assuming there is some sort of filter at the end of the tube which is wider, hence the resistance. Problem is, how can we check the pick-up tube if we cant get it out (and how did they get it in for that matter).

 

[Kmort]

Re: Fuel Tank/Pick-Up Tube Question

So you did un-screw the larger hex nut next to the tank and the pick-up tube still didn't come out?
Anyhow, I've not had much luck on this posting, but stay tuned just in case.

 

[Mak Daugherty]

Re: Fuel Tank/Pick-Up Tube Question

Correct. The metal threaded tube that the nut was on is where the plastic pick-up tube slides through. Mine pulls out roughly 6 inches and stops. I'm trying to make sure the filter isnt clogged. Cant figure out how you would replace it if it was....

 

[Chris1956]

Re: Fuel Tank/Pick-Up Tube Question

Those Moeller tanks sometimes had pressed in fuel withdrawl fittings. I needed to switch the pickup and vent on a flat tank. I was able to pull mine out, and thread the sleeve to accept a universal fuel pickup fitting.

Most of those pickups have a simple screen or nothing on the ends.

 

[Kmort]

Re: Fuel Tank/Pick-Up Tube Question

I promised...pics of my tank/pick-up tube. Can anybody tell me how the tube comes completely out?

 

[laderwell]

Re: Fuel Tank/Pick-Up Tube Question

Yes Sir,
Hold the hex nut stationary, disconnect your fuel hose and unscrew the fitting .Replace the anti siphon valve also

 

[Kmort]

Re: Fuel Tank/Pick-Up Tube Question

I've done that laderwell, but the tube only pulls up about 10 inches and stops. It will not clear that hexed nut.

 

[rbh]

Re: Fuel Tank/Pick-Up Tube Question

How about removing the fuel sender unit, put your fingers in that hole and pull the tube down and out through the senders hole???

 

[Kmort]

Re: Fuel Tank/Pick-Up Tube Question

Tried, but without success. Not enough room and or flexibility of the pick-up tube and I certainly didn't want to push my limits and break the tube and end up with a bigger problem.

 

[Beefer]

Re: Fuel Tank/Pick-Up Tube Question

Are you talking about the hex nut in the 2nd picture that is against the tank? I'd be really surprised if that didn't come off. It's not welded on, is it?

 

[Kmort]

Re: Fuel Tank/Pick-Up Tube Question

No it's not welded on. It's a plastic tank!!! I never tried removing the larger hexed nut for fear it may not suppose to be. That is basically the question I'm seeking an answer to. I only un-screwed the elbow fitting from the flat hex nut against the tank and the pick-tube only came up so far.

 

[Mak Daugherty]

Re: Fuel Tank/Pick-Up Tube Question

I looked a bit further into this. I removed the gas gauge sending unit and pulled the pickup tube as far out as I could. I then used a small mirror tool to attempt looking into the tank in the hopes of seeing what the obstruction was. I never was able to see anything as my tank is currently near full, and I could never get enough light into the area. I then poked around with my finder and noticed the pickup tube became extremely rough beginning right where it stops. I'm not sure if this is due to some corrison/chemical breakdown of the plastic tube, or if it's made that way. I recall hearing somewhere that the filter on these tubes is sometimes referred to as a "sock" that slides over the end of the pickup tube. Could this be the "roughness" I feel? And if so, I wonder is the old gas could have made this swell somehow. If that's the case, I wonder what the downside would be to just grabbing it with channel locks/etc and trying to "man-handle it out".

I'm also even wondering if that has been eliminated in my case, as I originally had serious WOT/low RPM issues. Sluggish acceleration and3000RPM at WOT. Since the carb rebuild, I now have smooth acceleration and 4000RPM at WOT. Spec is 4400-4800RPM, so I still have something amiss. Could the fuel pick-up tube be clogged enough that it would only show above 4000RPM. I see a bit of hesitation at WOT between 4000-4100 RPMs.

Final question - once I burn some of the fuel out, is there any merit in blowing out the pickup tube with air? (recommened by a backyard mechanic)

 

[BassHunter0123]

Re: Fuel Tank/Pick-Up Tube Question

I am having this very same problem!!!! i can pull this tube out and it just stops....noone seems to know whats going on either!.please keep me posted if you figure it out!

 

[Kmort]

Re: Fuel Tank/Pick-Up Tube Question

Having the same problem with the lack of power. When I give it full throttle the boat acts like it is under a load. It does get to plane and up to around 4200rpms before backing itself back down to around 3200 where it maintains.

As you guys can see, I've not got any where on here as to how to remove the pick-up tube. However, I have the fuel tank manufactor tag someplace in my papers and when I get a chance to get it I plan on trying to contact them about it. I will let you all know what I find out.

 

[dkellogg3]

Re: Fuel Tank/Pick-Up Tube Question

Just wondering if there's an update. I will be doing this next weekend.

 

[BassHunter0123]

Re: Fuel Tank/Pick-Up Tube Question

Just wondering if there's an update. I will be doing this next weekend.

yes i got mine out you just have to pull a little harder it will come out. there is a metal screen at the bottom and it is slightly bigger than the plastic tube that makes it stop from coming out easy.

 

[sea6ristle]

Re: Fuel Tank/Pick-Up Tube Question

Have had the same problem with a '02 Seapro. I pulled harder with a little twisting and the tube came out with a screen attached to the end. I'm guessing they heat it somehow when they put it on. The problem I had was trying to remove the aluminum Anti-Siphon valve. Snapped right off. So now I am in search of a replacement for the whole thing. I think I will remove the screen when I put it back in. Wish I didn't need to replace it with another aluminum fitting but the tank fitting is aluminum and mixing metals will just create a different problem. I think a lot of boat owners are having this problem.