Fuel tank problem

[Tim Procter]

T-Rex 700

The black bung in the front of the fuel tank has started leaking and dripping fuel slowly.

Although the bung still looks good and quite a tight fit it seeps through it and down the tank.

What is the best method of sealing this bung in the tank "ie" silicone or similar.

Cheers Tim.

[jamiem]

probably be better off replacing the bung, they can't be expensive. When you remove it check for any roughness on the hole in the tank and make sure it's clean and lined with a bit of fuel as you put it in. Idoubt you'd get the old one to reseal properly.

[Davewaddy]

Tim - remove the bung and check that the inner edge of the tank is smooth and no "spurs" of plastic are evident. De burr and then re fit bung and try to seat well by turning bung slightly.

[Tim Procter]

probably be better off replacing the bung, they can't be expensive.

Mmmmm

Had a look around and can't find the bung (only) to buy and replace anywhere.

The complete tank plus bungs etc was only £8.31 so I have ordered that from Fastlads.

For the moment I have re-seated the original bung back in the hole with some Silicone Adhesive Sealant, The same that fastens the governer sensor in the head. Dunno if it will work or not.

Waiting for it to set before I re-fill and test.

If it leaks then the new tank and bung will be fit tomorrow.

Bloody fuel makes a right mess of everything.

Thank Jamie and Dave for your replies though.

[machasm]

Hi Tim,
I had the same problem with mine.
Ended up putting a bit of sealant round it and all is well at the moment.
I have been told, though, that sealant might not be the best thing to use as small bits can come away in the tank and then work their way into the fuel system.
I've yet to experience the problem but haven't been flying the 700 much recently.
(I'll wait for warmer weather to fly the big bird).

[Matt Gill]

I had the problem on both my machines but I put it down to the fact that I was using YS engines that put a lot of pressure on the tank. I simply put a bolt through the bung with an old servo wheel (sanded down to fit) at the back of it, followed by a locking nut, inserted it into the tank and then tightened it up so the bung was 'bulb shape' in the tank and solid. Now no fuel can escape.

Simple idea but really effective. No problems ever since,30 gallons later.

cheers

matt