DL 50 problem

[kev40]

My DL 50 cuts off when you invert the plane in flight. I have now lost 2 planes to this motor. I have changed the fuel lines , the ignition, regs, and batteries. I also have pulled the carb. apart and cleaned, has maybe 5 gals. fuel through it. Motor ran great when I first got. Lost my Yak to this problem ran it on test stand and did fine. I put it on a Talon profile last week and on the 4th flight rolled inverted and the damn thing cut off. 50 feet off the ground could not make it back . Broke the plane into 3 peices. Has anyone got any ideas.

[JACK MARCOTT]

Did you also change the fuel line in the tank. My Da 50 was doing the same thing at the end of last year and it was the clunk line tubing that stiffen up and would dead stick inverted, usually when the tank was around half.

[WINDSURF]

Currently putting together my 89" carden yak 54 , and i too noticed how long it took for the fuel clunk to hit bottom when i did an inversion check on it. Took about 4 secs. Thats a high risk for fuel starvation as far as i'm concerned....Haven't finished building it yet....replaced the fuel line but the new one is not mutch better . I'll have to find out what line (gasoline) i can use, that will drop much quicker.
Sure must have been frustrating having that eng. die due to fuel starvation while inverted.
Anyone got a suggestion as to what line should be used for quick drop performance ?

[Awesome]

If it helps , i'm using black neoprene line for my clunk , flexy as anything , think you guys get it in the 'states by "Hayes neoprene" tubing. Here we get it off automotive suppliers , called "emissions line' . If you go the automotive stuff beware as there are two types here , seamless and moulded. You can tell the difference easily because the moulded stuff has a seam running down it. The seamless stuff is the go , doesn't split after time.

[WINDSURF]

ok , thx awesome....i'm going to check this out...it's a very critical issue.

[kev40]

Yes i did put new line in the tank, but it was the same brand as the old line. I will check it again.

[Pistolera]

You can also add some weight to the clunk. Wrap the hose (on the clunk barb) with copper wire, or something else. If you're good at brazing, many clunks are brass (sometimes plated), and it's fairly easy to braze on some additional weight. Then chuck it up in a drill press and clean it up with a good file. Check and/or re-drill your pickup hole afterwards.

Earle

[JoeAirPort]

You may want to install a 8-32 barb fitting on your carb vent plate. With certain installs the cowling turbulants can change you mixture as you change attitude. Another thing: if you know your engine has problems, fly high until the issue is resolved. I have a DL-50 that changed mixtures as you went inverted and knife edge. This pressure tap resolved it. Mine never quit though.

[WINDSURF]

	Quote: Originally Posted by JoeAirPort
	You may want to install a 8-32 barb fitting on your carb vent plate. With certain installs the cowling turbulants can change you mixture as you change attitude. Another thing: if you know your engine has problems, fly high until the issue is resolved. I have a DL-50 that changed mixtures as you went inverted and knife edge. This pressure tap resolved it. Mine never quit though.

I've previously heard of this remody...but if i'm not misstaken it also would require running a vent line from the 8-32 barb fitting , into the internal fusealage area ( where the atmospheric pressure is most stable ).Just having a barb fitting attached to the vent plate would not be enough. Am i right ?

[tailwheelteacher]

	Quote: Originally Posted by Pistolera
	You can also add some weight to the clunk. Wrap the hose (on the clunk barb) with copper wire, or something else. If you're good at brazing, many clunks are brass (sometimes plated), and it's fairly easy to braze on some additional weight. Then chuck it up in a drill press and clean it up with a good file. Check and/or re-drill your pickup hole afterwards. Earle

my clunk was a chrome one from a 50cc arf kit, i roughed it up with sandpaper then put some flux on it and ran beads of solder around the whole thing, it seemed to drop better inverted but i too think that the tygon is pretty stiff in there, how long does the black neoprene last??