MikeG4936

My Feedback: (5)

Hi everyone,

I am fairly new to the hobby, and I have a question about the assembly of the fuel tanks for some new ARFs I'm currently working on. The problem I have is that I assemble the tank EXACTLY according to instructions, but when I fill the tank with fuel, the silicone fuel pickup line (the one with the clunk) always slips off the brass fitting inside the tank (during fueling). It's a major pain because I always have to remove and open the tank to re-secure the tubing to the brass tube. And no, I'm not using silicone line that is too large in diameter. I've heard that one way to secure the fuel line to the brass tubing is to use a metal twist tie... is that what I should be doing? Any tips? THANKS!!!

-Mike

w8ye

My Feedback: (16)

Metal twist ties, plastic electrician's wire wraps, fine brass, copper, or aluminum wire

Cyclic Hardover

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I throw away every fuel tank that comes with Arfs, Theyare unreliable. New tanks are only a few dollars. Not worth the risk of stuffing a nice plane

gjeffers

and i throw away all the hardware except the fuel tank that comes with arfs,never had a problem with 7 of them[X(], and never had a line want to come off, how long is the brass line sticking out on the inside where the line slides on?3/4in is about my minimum.

blw

My Feedback: (3)

You can get some larger diameter fuel tubing and slip a short piece over the end of your fuel line where it grabs the brass line. You are doubling up the fuel line over the brass tubing. Be sure to not have excess extra tubing that will squeeze down past the brass tubing and reduce the inner diameter of the fuel line. I've had to do that in several situations. One is where the fuel line slips off of the nipple on the carb! About 1/4" over the very end at the nipple stopped that problem.

MikeG4936

My Feedback: (5)

Sounds good guys, thanks for the info.

gjeffers -

I DO have less than 3/4 inch brass tubing inside the tank, because the tank is very small at only 2.5 oz. (came with a Sportsman Avaition Aero Princess). I think I'll try a combination of blwblw's and w8ye's tips. Thanks again!!

NM2K

My Feedback: (14)

Plumbing really small fuel tanks is really a PITA. That is one reason that I usually avoid small planes, even though I love .07 to .15 sized engines.

If someone were smart, they could have a nice steady stream of income, albeit not large, if they could solve these problems and market the tubing and other accessories that would make a small fuel tank viable.

MikeG4936

My Feedback: (5)

You can say that again!!

The HARDEST part of assembling the plane was getting the clunk to work! I spent days trying different combinations of clunks/fuel lines, and I finally settled with the most flexible tubing I could find and put the biggest clunk on the end.

Flyboy Dave

My Feedback: (21)

This is what blwblw was talking about. Take another piece of fuel line
and put it over the existing line....is makes like a clamp. You would be
suprised how much harder it is to pull the fuel line off, when this "clamp"
is used.

FBD.

Flyboy Dave

My Feedback: (21)

See the pink "clamps" over the blue fuel line on this YS fuel system ? I
use this method because the fuel ststem is pressurized, and you don't
want a line coming off, or problems like that.

FBD.

Flyboy Dave

My Feedback: (21)

By the way, I never used these remote fuelers. I heard they were not
reliable....so I went with fuel dots instead, and it was good advice.

The other fuel line is pink, with blue clamps.

FBD.

Dr1Driver

No metal or wire ties, they will eventually cut into the fuel line. Flyboy Dave has the right solution. Use a 1/8" long piece of the same tubing and stretch it over the connection.

Dr.1

MikeG4936

My Feedback: (5)

Thanks for the advice and pictures - you guys are the greatest!

FBD - I really appreciate the pictures. I already knew what to do per blwblw's suggestion, but I never would have guessed to use needle nose pliers to get the 'clamps' on. Now I can get to work!

Thanks again!

blw

My Feedback: (3)

changed my name to blw from blwblw,

I carry some forceps in my flight box. They have more narrow jaws than needle nose pliers.

cruzomatic

My Feedback: (17)

I use zip ties. Cheap and reliable insurance so it doesn't come off.

Ernie Misner

Hmmm, what no one has discussed is the fact that pressure is building up inside of the fuel line between the brass tubing and the clunk area. What type of fuel pump are you using? If electric, perhaps (on this tiny tank setup) go to a hand crank pump where you can pump it really slow and avoid so much pressure buildup. Also, you might inspect the size of the opening in the clunk, and drill it out a bit larger if possible to avoid psi buildup as you pump.

Ernie

MikeG4936

My Feedback: (5)

Huh, now that you mention that, I think thats what the problem is. While I do only use a hand-crank pump, I always seem to gun it and pump at 100 MPH for no obvious reason.

Thanks for pointing that out.

Also, zip ties DO seem like a good solution - I wonder if they are better than the already suggested fuel tubing "clamps?"