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Where to install a fuel dot???

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Where to install a fuel dot???

Old 01-10-2007, 09:58 PM
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Timbotide
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Default Where to install a fuel dot???

I just converted the tank on my Alpha 40 to a 3 line system and want to add a fuel dot. Does the dot need to be mounted at a point above where the line goes into the fuel tank or can installed below said point.
Old 01-10-2007, 10:48 PM
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Richard L.
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Default RE: Where to install a fuel dot???

It doesn't matter if you use a fuel pump because you will be pumping fuel into the line with the dot, and the engine doesn't draw fuel from that line. If you want to siphon fuel into the tank via gravity, then mount the dot above the tank.
Old 01-11-2007, 02:24 AM
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Kmot
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Default RE: Where to install a fuel dot???

Put it anywhere it is convenient and aesthetically pleasing to your eye.
Old 01-11-2007, 09:09 AM
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Timbotide
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Default RE: Where to install a fuel dot???

Thanks guys. I was afraid that I would goof and install it too low. The dot I have is a Hangar 9. How much slack tubing should I leave to hang out the dot when refueling and should the plug be a very tight fit in the tube?? Thanks again.
Old 01-11-2007, 09:53 AM
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vicman
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Default RE: Where to install a fuel dot???

The idea of using the 3 line system is to make fueling a little easier. Ala not disconnecting the carb line in a coweled engine.
Your fill line needs to be long enough so that you aren't reaching around and turning your model over etc. but will not get caught in the prop or other flight/landing critical moving parts. Also as Kmot stated you want it to look somwhat decent.
On goof around planes mine come out the top and flap in the air. Otherwise they are neatly tucked up under the cowel but never long enough to reach the prop.
There is also a kit to mount a collar that holds the whole deal right to the side of the fuse or thru the cowel.
Old 01-11-2007, 10:22 AM
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Richard L.
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Default RE: Where to install a fuel dot???

ORIGINAL: vicman

On goof around planes mine come out the top and flap in the air.
Are you talking about a line with fuel dot here? A line capped with a fuel dot will never flap in the air and will not get caught in the prop or other critical parts. A fuel dot already comes with a washer and nut to mount it to the fuse or cowel, so it's not necessary to buy a kit to mount it (there isn't a kit for it anyway). I think you are talking about a free floating line. Here are some pics of my fuel dots:









Leave around an inch of slack between the cowl and the end of the fuel tubing so you can pull it out.
Old 01-11-2007, 10:41 AM
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vicman
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Default RE: Where to install a fuel dot???

See, he has the high dollar pretty ones that mount to the fuse. I got the 5 for $5 dubro jobs that simply plug the end of the line. I have used the ones like Richard has in the past tho.
Old 01-11-2007, 11:31 AM
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Timbotide
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Default RE: Where to install a fuel dot???

I will try to find a good place to mount the dot. One that is above the line of the clunk. Do you guys use the thin wall tubing when adding lines to a tank. I noticed the existing line that Hangar 9 had on the clunk is smaller in OD than the tubing I used to add the third line. Should I have used thinwall tubing instead of the thicker stuff. The extra clunk seems to flop around just fine so far.
Old 01-11-2007, 11:46 AM
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vicman
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Default RE: Where to install a fuel dot???

I use normal fuel line for everything. You don't need anything inside the tank for the filler. It can just be a straight line in. you want your exhaust line to come in and bend up to the top of the tank to allow you to fill it all the way, this also prevents pumping in so many airbubbles and foaming of your fuel while the engine is running. I can take a pic of the Sullivan tank instructions if you need.
Old 01-11-2007, 12:31 PM
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Kmot
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Default RE: Where to install a fuel dot???

Like vicman, I have used the Dubro. I also have the Hangar 9, and the PSP versions like Richard L showed you. They all work exactly the same.

Here is a pic of a Dubro installed on my F-20:
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Old 01-11-2007, 01:21 PM
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Default RE: Where to install a fuel dot???

ORIGINAL: vicman

I use normal fuel line for everything. You don't need anything inside the tank for the filler. It can just be a straight line in. you want your exhaust line to come in and bend up to the top of the tank to allow you to fill it all the way, this also prevents pumping in so many airbubbles and foaming of your fuel while the engine is running. I can take a pic of the Sullivan tank instructions if you need.

vicman

Do you you a clunk on the fill line and if so has it ever got in the way of the clunk that is on the line that feeds the carb. Since I am new to the hobby I want to do the right thing. The clunk that I have on my filler line is almost 1/2" shorter than the clunk on the other line. I also notice the plug that came with the Hangar 9 dot is a very tight fit in the line and takes alot of effort to pull it from the line. Should it be this way??
Another thing is where is the best place to install the dubro fuel filter. Does it need to go between the tank and the needle valve or between the needle valve and the carb. Dubro shows it mounted between the needle valve and the carb. Thanks again.

Old 01-11-2007, 01:36 PM
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Default RE: Where to install a fuel dot???

No clunk on the fill line!
It fits tight so no fuel leaks out. Keep in mind it has the same pressure against it as the carb line.

Here are thousands of words and a breezy fuel dot
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Old 01-11-2007, 01:59 PM
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Richard L.
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Default RE: Where to install a fuel dot???

I have a clunk on the fill line in my 3-line setup with OS engines, and it sits slightly ahead of the feed line so they don't interfere with each other. No problems. With YS 4-strokes, I only need 2 lines going to the tank.
Old 01-11-2007, 04:28 PM
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Default RE: Where to install a fuel dot???

Richard, what is your reasoning behind having another clunk?
Old 01-11-2007, 05:16 PM
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Default RE: Where to install a fuel dot???

One important note that should be mentioned here. Before you drill the hole for the fuel dot, make sure you have acces to the backside, so you can use a tool to tighten the retaining nut. Been there, done that.
Old 01-11-2007, 10:21 PM
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Default RE: Where to install a fuel dot???


ORIGINAL: vicman

Richard, what is your reasoning behind having another clunk?
So I can drain the tank when I'm done flying at the end of the day.
Old 01-13-2007, 05:54 PM
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Default RE: Where to install a fuel dot???

Pardon my ignorance but if you start pumping fuel into the '3rd' tube and your needle valve is open to the standard 2-3-4 turns, won't it flood the engine? Or does the 'path of least resistance' play here and air pressure is exhausted to muffler line - thus no worries.

I too am setting up a fuel-dot contraption and wanted to make sure this wouldn't be the case. Also, how do you know when to stop filling with a 4-stroke....just watch fuel come out the muffler?

Thanks!
Wiqar
Old 01-13-2007, 06:52 PM
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Richard L.
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Default RE: Where to install a fuel dot???

Yes, air pressure is exhausted out the vent line. No flooding, no worries. Just watch for fuel coming out of the muffler to determine if the tank is full.
Old 01-13-2007, 07:13 PM
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whidbey1
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Default RE: Where to install a fuel dot???

HI
I fly Giant scale planes, I have been installing fuel dots on the side of the fuse, so when you remove the cowel you do not have to undo any fuel plumbing.


My Two Cents

Bill
Old 01-13-2007, 07:33 PM
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Richard L.
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Default RE: Where to install a fuel dot???

I also install fuel dots on the side of the fuse myself when possible. Since my fuel tank is usually mounted on the CG, it's easier and better to mount the fuel dots on fuse.
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