RCU Forums - fuel dots

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what is a fuel dot? And, why would you use one?

Rather than have to pull the line off the carb of off a fuel filter every time you want to fill up, you either use a "t" in the fuel line or a third, dedicated line to fill the airplane. The fuel dot is used to plug the end of the line. If you have a cowled airplane, the outer part of teh dot is mounted into your cowl, and the inner part of the dot, that actually plugs the fuel line, is pressed into place inside it. It holds it securely, and is a lot neater than having a fuel line dangling out the bottom of your airplane.

This is the best pic I have of a fuel dot. This is the Du-Bro setup. The center pulls out, with the fuel hose plugged into the rear of it. The outer part stays with the cowl. Very neat install.

I just ordered a ME-109 that has a cowl (obviously), and I have been thinking about this fuel dot thing. Is it something the LHS has? I'm not totaly clear on how this thing is attached and works....

yes most LHS have them either great planes or dubro

alright i found a neat pic that explian it to me. but now my question is.

You know how there is a T crossing hooked up to the muffler hook up... Don't you think you'll still get fuel in the muffler?

K.I.S.S - - The main reason to use fuel dots IMO is that they are simple and little can go wrong. I think most of us that have flown for awhile have been bit by a fancy fuel valve that has failed. And as Murphy's law dictates, the valve will fail (and shut off your engine) at the worse possible time. A fuel dot is just a glorified plug and socket. The plug goes in the end of the fuel line and then you shove the works back into the socket for storage during the flight. Simple. A basic hole drilled in your fuse/cowl with the lines sticking out would work... just plug the lines. The dot kits build on the same idea but they include fancy liners for the holes you will drill. Many makers of dots, GP, Dubro, MK Products, Tettra, etc.

Fuel dots I have used
http://www.centralhobbies.com/Fuel/f...ngs/CHFLD.html

Righty: Yes, a little. Tank shouldn't siphon as per your drawing; however, you may get small squirts of fuel in the muffler when transitioning from inverted to right side up. You can minimize this effect by placing a few loops (2 or 3) in the vent line, fasten with velcro, zip ties, tec. This will help stop any siphon effect.

Okay....so lets see....I have a U Can Do 3D 46. It has a cowl and the engine is mounted upside down. Thus, giving a not to great
area for glow plug changing etc. And the fuel tank has 3 holes in the cap, 1 for breather (to the muffler), one for the actual fuel line to
the needle valve. The last one being for re-fueling. If one were to use all three of these in this particular model, you could run a re-fueling
line to the cowl, drill a hole and cap the dang thing with this fuel dot. Would that be a correct usage of fuel dots?

Dave...

Like in the diagram above, make sure the third line (INside the tank) goes to the bottom. It doesn't need a clunk, just bend the tubing so that the silicon line stays at the bottom of the tank. Reason: You want to use that line for DE-Fueling too!

Joe,
What stops fuel from flowing into the carb with that "miracle fueler"? Sure the "Y" should reduce that, but it probably won't prevent it entirely. Just playing devil's advocate here.

I've never had a problem with a dot coming loose, but have had a couple that were a bit tight.

Righty,
If you're concerned about fuel flowing into the muffler during re-fueling with the set up in your diagram, you could always put a check valve in the line to the muffler (after the "T").
Dennis-

whats a check vavle?

A check valve is a valve that only allows flow in one direction. Installed between the "T" and the muffler, it would allow the exhaust pressure from the muffler to flow to the tank, but when pumping fuel into the tank any excess fuel would have to flow to the outlet, and not to the muffler.
Dennis-