Hi there
I am trying to help my son put a old tower trainer to 40 back together that someone had gave him we bought a new fuel tank for it and it has 3 outlets I know one goes to the carb and one is a fuel fill line but my question is the other one It has a old kb-40 and on the muffler there is a nipple for a hose does it go there And if so why? and do I need to block the line off to keep it from pulling fuel out with the vacuume of the exhaust any help would be great. Thanks

yep it goes to the nipple of you pipe. and just like you said one is the carb line then a fill line then a psi form the muffer to the tank

Thanks dragnbye
Do I leave that line to the muffler open, or block it off in the tank. won't the exhaust pull fuel out of the tank. Sorry I sound so dumb but this is all new to me.

No, the opposite, the muffler supplies pressure to the tank that you need, do not block it.
One of the lines going into the tank will have a tube to the top of the tank. This is the one that goes on the muffler.

missleman
Thanks for your help I had the fill hose going to the line on the top. I will change that by putting the line on the top to the exhaust, the line with the hose and weight to the carb and the other outlet to the fuel fill correct? Thanks

Hi Dave Jackson
Is your new fuel tank a Hayes tank? If it is, it has three connections like you reported. The top one goes to the muffler nipple and provides pressure from the muffler to help move the fuel to the carburator. The center connection is blocked. There is a nipple there, but there is no hole into the tank. Leave it that way. The lower connection is the one that has the short line and klunk, both inside the tank. The nipple outside connects to the fuel valve inlet. Suggest you look up a flying club and get some instructions.

Hi Villa
I dont know what brand the tank is. But I just checked and it doe's have all three outlets open none of them are blocked.
Thanks

One should go to the top, the other 2 should go to the bottom, a couple of ways to do the bottom 2.
1. both have a tube and weight (called a clunk) that go all the way to the back of the tank but not touching the back (it needs to be able to move to the top of the tank when you are flying upside down. With this setup either of the 2 will go to the carb or use for fueling.
2. only one has a line and clunk and the other has a tube angle to near the bottom front of the tank. In this setup the one with the line and clunk goes to the carb, the tube angled down is for fueling.
The line going to the top of the tank goes to the muffler.
ALL that said with a tower trainer you don't need a 3 line setup, that is for a coweled engine. I would eliminate one of the bottom lines.
When fueling pull the line off the carb and fuel.(it is ok to pull the line off the muffler also while fueling so when the tank gets full it will not pump fuel into your muffler)

I would do as missileman stated and just replace the tank stopper with a new one and make it a two line set up. Make the pressure, muffler, line go to the top of the tank from inside the tank by bending the tube line up untill it is just below touching the top of the tank and then put a clunk on the second line, like stated the line that goes to the carb, making sure it does not touch the rear of the tank and does move around free inside the tank. Now all you have to do is remove the line from your carb to fuel/unfuel. One less fuel line to worry about leaking air latter on that way.
You can just remove the pressure line when fulling and when fuel comes out that line it is full and nothing will enter the muffler.

You can keep the 3-line setup, but make sure you plug the "Fill" line after filling or the muffler pressure will escape.

You can plug it with anything from a small dowl to a golf tee. With cowled-in engines, a lot of us use something called a "Fuel Dot" which is just a fancy plug.

See diagram below:

Hi Guys
Thank you for all your help. I now know the purpose of all the lines and how they go. I really think it is great to have a forum like this and have people willing to help a rookie like me out. Now maybe tonight my son and I can finish getting it back together.
Thanks again
Dave