Hey guys, Im having really serious problems with my DA 50, everything was ok, until 3 weeks ago, but now I cant get it working fine, It does not acelerate well fast, it takes like a second to go to full throttle, I have tryed closing the low niddle valve, but as much as I close it, it does not work any diferent :S, please any help??, I have tryed by openig the low valve, but the problem gets worst.

Read ALL of this first before trying anything else.
http://tech.flygsw.org/walbro_tuneup.htm

Also, read this
http://tech.flygsw.org/DA50Review.htm

Question... If there is no idle FUEL adjustment, what is the low speed needle for ?
I GUARANTEE the engine will stop idling (from no fuel) if you close the low speed needle...
And while we're at it, all you people who set the low speed needle first, try closing the high needle all the way while you set the low needle first....
2 turns out on both, set the high for max first, the the low..Has worked for me for 21 or so years, but what do I know, one foot is in the grave....

Like I said...
Read ALL of the page from the above link and you will have a complete understanding of how to tune a Walbro carburetor.
Basically, in a nutshell, tune high needle for peak RPM then start tuning low speed needle all the way down to idle. Then, check your high speed needle again for peak RPM and repeat low speed needle adjustment if necessary.
Its all spelled out on the page and really easy to follow

By the way... if you close the low speed needle all the way the engine will quit from LACK of air

Man, I closed both needle valves, and opened 2 turns, now I cant start the engine!! :S, the carburator is really wet and also the spark plug, what should I do?

Sounds like its a bit flooded, take spark plug out, disconnect fuel supply and flip the prop several times to clear most of the fuel from the cylinder. Dry the plug with a rag and put it back in the engine.
The Desert Aircraft manual says for initial tuning start with the low speed needle set to 1-5/8 open and the high speed needle set to 1-7/8 open.
To be clear, the low needle is the one closest to the engine.
When you try to start it again make sure you have choke on and ignition on, then flip the prop until she pops, then open the choke and the next flip of the prop should start her up.

Well I have tryed these for several times, but the carburator is droping lot of gasoline..., and Im getting desesparate ! lol.

Well, Finaly it started, but it has a really low aceleration, and at idle it get off, should I open or close the los speed valve?

Close the low speed needle a bit and see if that will help with the acceleration. Also you may want to try a new spark plug. The plug being exposed to alot of fuel could have fouled it.

If he's leaking fuel as he says.... I wonder if his pump diaphram is compromised... would also explain the lack of acceleration.

Yeah the spark plug is new... I cant see any diference by closing or bye opening the speed valve, I think theres a bigger problem :S

Check the diaphram and the needle and seat. Sounds like it could have dirt in the needle.

yeah I`ll take it off, will tell you of any problem..

The LOW speed needle is the one that controls the FUEL passing through the 3 little holes in the venturi, covered by a welch plug...There is no AIR ever going through those holes, and there is no way to get AIR in there.....They get FUEL from a small hole in the carb body at the end of the low speed needle..Closing the needle shuts off the FUEL to those holes.....The low SPEED screw on the side of the carb that keeps the throttle disc from closing controls the AIR through the carb.....
Take one apart and look, don't just believe something because it's posted....
If you're REALLY curious, call Mr Luis Salas at Walbro in Cass City...He Knows more about Walbros than anyone on here.....
1 989 812 7322

Originally Posted by rcign

The LOW speed needle is the one that controls the FUEL passing through the 3 little holes in the venturi, covered by a welch plug...There is no AIR ever going through those holes, and there is no way to get AIR in there.....They get FUEL from a small hole in the carb body at the end of the low speed needle..Closing the needle shuts off the FUEL to those holes.....The low SPEED screw on the side of the carb that keeps the throttle disc from closing controls the AIR through the carb.....
Take one apart and look, don't just believe something because it's posted....
If you're REALLY curious, call Mr Luis Salas at Walbro in Cass City...He Knows more about Walbros than anyone on here.....
1 989 812 7322

I stand corrected sir.
I was basing my knowledge on what seemed like a very well written and informative article. I was under the impression that the article was written from information gathered from Walbro carburetors. The very same web page has links to the Walbro website.
Perhaps Mr. Mark Fuess would like to step into this thread and explain the discrepancies.