G'day all,

i have got an 8oz tank with 3 lines coming out of it, one to fill the tank, one to run the motor and one to the exhaust, Now when i goto prime the engine i can see the fuel running into the exhaust instead of into the engine line the tank is in the right way i just don't understand what is going on ive been scratching my head for hours now, the planes i have had before this have only had 2 lines going into the tank this is my first tank with 3 lines. For those that need to know the engine is a O.S 46LA 2 stroke 100 buck bargin!

Any info would be great thank you for reading

Happy Flying
Paul

Are you priming the engine by giving it full throttle (with the engine off), plugging the carburetor with your thumb, and flipping the propeller? Are you sure your fuel tank is plumbed properly? My first guess is that you have the supply line and the pressure line reversed.

Yeah i always doit with the throttle open fully with my thumb over the carb i tried swaping the lines over and that don't really do anything either same thing happens with the lines changed its really odd and people i have called who are in the club have said they have never hadthe problem im having,

Thankyou for resonding so promptly


Any other advice will be used and abused on my fuel lines! hehehe

Happy Flying
Paul

I also agree that you have the carb and pressure lines reversed

If it is a low wing airplane, you might have the tank installed upside down when the model is right side up.

G'day Paul
Is the engine side mounted or inverted? This puts the muffler below the top level of the tank so you might be getting syphoning, especially if you use the pressure line as the vent when filling. If this is the case then the cure is to loop the pressure line up above the top level of the tank and make sure it's full of air after filling up.

fuild goes to the area of least resistance, your muffler

I've never liked the hold your finger over the carb for priming for this reason. I hold my finger over the exuast port this stops the path of least resistance to the muffler and pushes it to the carb.

I think I would fill through the muffler line and use the 3rd line as an overflow. I would plug the third line and then reconnect the muffler line. I had a situation where the muffler was below the fuel tank. If I replaced the muffler line and then plugged the overflow, it would start a rapid siphon into the muffler. Priming by plugging the end of the muffler and flipping is not a bad idea.

Sounds like REVERSED lines to me. ENJOY !!! RED

I know a simple way to find out if there’s a problem inside the tank.
Drain all but an ounce or so from the tank.
Plug the fill line.
Remove the line from the carb and put the end in a bottle or cup.
Remove the muffler pressure line and blow air into it.

If fuel flows into the cup or bottle there’s a pretty good chance the clunk and line is ok.

Thank you all for your input's i found the problem to be a screw i had in the 3rd line for fuel air was getting in and not allowing the fuel to go through the engine, so there you go hehe never use a screw to plug up the fuel line, air still gets in! hehehehe Thankyou all again for the info i went through all these stages you all recommended in the end it only took around 18 hours to work out what was wrong haha now i can fly!

Happy Flying all
Paul

You would be amazed how many people think you can block a fuel line with a screw. I like BB's myself. Glad you figured it out.