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        New YS .63, have it now, and have some questions..

#1 DsWright Jul 20, 2005 12:49 PM

New YS .63, have it now, and have some questions..
the instructions say to unhook the pressure line to depressurize the tank then fill through the fuel line....

How can i achieve this under the Cowl of the goldberg matrix i want to put this in?

What is a fuel dot?

Why is a fuel dot different than the GP fueling valve i have seen around, but some have said not to use on a YS engine...

can i just add a filler line to the tank that will hang a bit out of the botom of the cowl and use a normal line plug? or will the pressure from the YS blow the plug out of it all the time?


#2 SamD Jul 20, 2005 01:20 PM

The fuel dot is used to depressurize the tank when fueling; if you want to run an extra line with a plug, you can do this but you're adding complication to the system. The fueling valve is fine; simply install where you'd install the "TEE" for the fill line. The fuel dot can physically be placed adjacent to the fueling valve. Take a look at this for a pic of a fuel dot: http://www.dldesigns.net/dot2.htm. A search on the 'net will net you all manner of fuel dots; take your pick. Make sure you have the check valve installed in the correct line and the correct orientation; the instructions that come with the engine outline exactly what is needed for the fuel system. Use 20/20 YS fuel and you're set to go.

#3 DsWright Jul 20, 2005 01:23 PM

So the GP fueling valve is fine? will it depressureize the system before i add fuel?

#4 DsWright Jul 20, 2005 01:36 PM

or install a filler valve and a fuel dot side by side? read that again a few times and it made more sense....

where can i buy a fillervalve and a fuel dot both online? can't seem to find a site that sells dots and a couple other things i need also, like some electric props... saving shipping is good=)

#5 SamD Jul 20, 2005 06:34 PM

You need to depressurize the system prior to filling- so the GP filler valve will be fine. The only time the fuel system is pressurized is while the engine is running and after you shut the engine down (until you depressurize). When you store the plane, it's a good idea to depressurize the system (which you should have done if you'd drained the tank); the rubber stopper in the end of the tank, can, over time, migrate out if you leave pressure in the tank constantly (don't ask how I know this). Caution: don't pull the fuel dot off with the fuel line pointed at you! You'll only do that once before you make sure it's pointing away from you....:-)

#6 Jeffery Jul 20, 2005 10:08 PM

The fueler valves are not absolutely bullet proof. Use fuel dots and tees. Use an OS F plug and a 20/20 blend fuel. Run a filter between the tank and engine and between the engine and check valve. Don't try to run the engine too rich, just 300 or so off peak.Do these things and you will have a lot of trouble free operation. Central Hobbies has the dots and tees.


#7 SamD Jul 21, 2005 07:05 AM

Note on filters: The YS .63 manual does not show (2) filters as do the manuals for the larger YS engines. That being said, I'm running (2) filters on the .63 I'm currently using. Between tees, filters, & check valves, things can get cramped in a tight engine install; check out these: http://www.centralhobbies.com/Fuel/f...a/TET4307.html for a bit more compact set up (filter & tee as one unit). Central also sells a very small filter not listed on their website (can't remember the exact name but they'll know) that is much more compact than anything you'll see in the hobby shop or elsewhere.

The dots & tees are pretty fool-proof but, on the other hand, I've never had a problem with the Dubro filler valves in this application so I suppose I'll continue using them.

#8 DsWright Jul 21, 2005 07:30 AM

I went with dots and Tee's Thanks for the recommendation.

I shouldn't have to much trouble getting the filters and everything plumbed into the fuse, it's Going in a goldberg Matrix 3D, the tank is located on the CG and i have a decent amount of room to plumb the fuel system.

When filling, you fill from the checkvalve line to keep it from pushing fuel into the motor correct?

#9 Majortomski Jul 21, 2005 07:32 AM

Boy this thread went round and round.

The simple answer was back in post #2, use two fuel dots. One in the pressure line between the tank and the check valve and one in the fuel line between the tank and the carb.

Pull the pressure line dot out first and depresurize the system. Then pull the fuel line dot and fuel the plane. When the tank is full, fuel will come out of the pressure dot.

You can use two GP fuelers in place of the Dots. You will need to make a vent tube for the pressureline. A piece of tubing on the fueler plug. Install this plug on the pressure line to vent the system. Then add your fueling line to the other GP fueling plug and fuel the tank.

In either case the line between the tank and the check valve must be open to the atmosphere while fueling and sealed while running.

Using just one GP fuel plug on the fuel line will not work. Yes, when you plug the fuel line in from the can, the pressure in the system may blow back into you fueling can, but that's not guaranteed. Then without the pressureline vented your fueling can pump is only going to pressurise the tank in the airplane.

Two lines two vents.


#10 SamD Jul 21, 2005 10:27 AM

It can be definitively stated that the fuel system on a YS will definitely work with a single fueling valve and a tee with a dot; there's no need for two (2) fueling valves.

#11 DsWright Jul 21, 2005 11:05 AM

should i just put 1 dot on the pressure line then between the tank and the check valve? so when i open it up, relieved pressure.... is the fuel going into the tank from the pump going to force fuel into the regulator/carb and overprime it? or will it dump fuel all over if i overfill it?

Seems like there has to be someplace for the air in the tank to go.... but im also thinking it would force fuel out before air if i did it through the pressure side.... what if this was done through the fuel delivery side? how does the air from the tank escape if the pressure line has a check valve on it?

#12 Majortomski Jul 23, 2005 09:31 PM

Ok for the one dot and one fueler configuration.

The fueler is in essence a "T" that allows fuel to either flow from the tank to the carb, or with the fueler installed cuts off the route to the carb and the new fuel goes to the tank.

The pressureline from the check valve to the engine will be cut and you will put a "T" fitting in that. The new third line off the T is long enough to go through the fuel dot fitting. YOu plug the fuel dot into this new line then push both of them back down into the fuselage. The dot is now almost flush in its fitting in the side of the plane.

To fuel pull up the dot line, pull out the dot. Hook up you GP fueler and fuel. When the tank is full the excess will come out the dot line.

The fueler is preventing the carb from flooding, the check valve is preventing fuel from going backwards into the engine.



#13 SpadZombie Jul 23, 2005 11:26 PM


Here's a picture for you. To read the article and setup information go to the Aircraft Proving Grounds. Very good information on YS engines, setup, and tuning.


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