Refuelling probs!

[Billy BobParticipant @billybob24045]

Hiya guys,

I have recently purchased a second hand nitro boat.  All is good, but I am having difficulty refuelling the tank.  The problem I have is this fuel cell has 3 pipes leading from it.  1 pipe leads to exhaust chamber in order to pull fuel, second pipe leads to carburettor, this leaves me with a 3rd pipe which has been cut at length with a detachable bung which I assume is where you should be able to pump fuel in order to refuel the tank. 

Trouble is, when I hand pump fuel through this 3rd tube, I am finding I get to about 1/4 full then the pressure in the tank seems to push fuel towards exhaust pipe as well as the carburettor in turn filling air filter and exhaust with fuel. 

There has got to be a way of releasing pressure on the tank while filling, so it doesn’t create so much back pressure.  I have even tried disconnecting various tubes in order to equalise the pressure but still end up in an oily mess. 

The missus keeps making me clean the floor! 

What do you reckon? Am I missing something stoopid here?

Thanks in advance.

Billy Bob

[TelstarParticipant @telstar]

Hi Billy Bob

It sounds like you have a Clunk tank these are used a lot by the fly boys. 

The 3 tubes should be :-  a straight tube into the tank with a flexable tube inside with a weight/filter on the end, to ‘clunk’ to the bottom of the tank.   This is the fuel supply to the carburettor

                                          :- 2 tubes bent almost at right angles inside the tank. One of these should be pointing up to the top of the tank, and be fairly close to the top. This is the pressure pipe and goes to the exhaust system (to pressuise the fuel system when running).

The second one is the filler and is plugged in normal use.  This one can be pointing any way, but I usually have it pointing down to the bottom of the tank, this allows me to use it to empty the tank as well as fill it.

It sound as if your two pipes are pointing across the tank, and as such won’t let you vent above half way

Cheers Tom

[Billy BobParticipant @billybob24045]

Thanks for that Tom,

Ive found out that, if i fit the pump into the pipe that goes the exhaust pipe, and that pipe with the detachable bung, well take that out ! It kinda releases the pressure in the tank enough in order to fill the tank!!!

Btw yr right about there being little bent right angle pipes in side the tank.

I got the jist of how it all works now regarding pressure flow.

Cheers tom, nice 1

Billybob…

[Billy BobParticipant @billybob24045]

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