DA-50 Walbro carb issues...
 

I have any early serial number DA-50 that has just come back from DA for a work-over... They replaced the con rod & bearings, new plug, set the timing and I had asked them to check the carb as I have never been able to get this engine tuned properly... They took care of everything but the carb... I need some advice on a direction to go...

I can't get the needles rich in any way... At factory setting, 1 1/2 turns out on high & low, it won't even start... I have to set the high at 2 turns out and the low at 3 turns out to get it to start... It's still way lean even at those settings... I have tried the low end opened to 4 turns out and it's still lean... It'll run for awhile, then will usually lean out on transition like it's starving for fuel and die... The plumbing is tight... Ignition is known good... Carb is clean... No blocked passages, meter bar is flush with the top of the casing, screen is clean, carb reed block mod done...

None of my other DA-50's have problems like this... 1 1/4 out on low and 1 5/8 out on high... Flip & fly...

What should I do???

1.) Get a rebuild kit with new diaphragms & gaskets??? If so, from where???

2.) Call DA and get a new walbro carb???

3.) Is there another source for blueprinted Walbro WT series carbs???

4.) Punt... (not an option)

RE: DA-50 Walbro carb issues...
 

Simple. Call DA and get a new carb. Those are great carbs and you obviously have been putting up with a problem for a long time. So just get another one and start new.


3dbob

RE: DA-50 Walbro carb issues...
 

Yep! Why torture yourself over it..you obviously know what your doing since you have another that runs perfect..Im sure DA will just send you a new one..

RE: DA-50 Walbro carb issues...
 

The stock 201 carb could sometimes use a little help, it was discussed on here a while back...A WT76 works well, but the 201 can be made to work just fine also...Call Dave and get a different carb or do a search...

RE: DA-50 Walbro carb issues...
 

Send that man a box of 0-80 drills.

RE: DA-50 Walbro carb issues...
 

Ralph,
Do you know of a way to extract data out of the Walbro carb codes? Or is it just a random number? I have a feeling there must be system in that diversity.
Looking for:
Neck size (valve dia)
venturi size number
Main jet size
Idle jet size

RE: DA-50 Walbro carb issues...
 

I think the numbers are just random...Walbro carbs are calibrated to the original engine's requirements...Airplane engine manufacturers try a few different models and use what fits best...I was told by Walbro that they could calibrate carbs for airplane engines, but I guess no one has had it done...The WT499 flows enough to be used with glow fuel without any mods, and there may be more.
I will call Walbro today and find out...[8D]

RE: DA-50 Walbro carb issues...
 

While you are at it, could you find out how the suffixes are assigned.
For example, what is the difference between a WT-201, a WT-201-1, and a WT-201B?
Are these just minor accessory changes, or differences which would impact metering/performance?

RE: DA-50 Walbro carb issues...
 

Thanks for the input guys... I just spoke with Jeff at DA and they are sending me a new carb today...

As far as the nomenclature on the carb that I've got now, it doesn't have 201 stamped anywhere on the carb body... The only numbers stamped on it are "D33" on the carb body and "288" on the inside of the pump cover... The serial number on this DA-50 is DA0431, so who knows what carb they were using at that point...

RE: DA-50 Walbro carb issues...
 

They probably stole it and filed off the serial numbers so no one could trace it.

This is a test -It is only a test !

RE: DA-50 Walbro carb issues...
 

Suffixes generally denote different ways to connect the throttle, the internals should be the same...The very old G62 came with an HDA 48 carb..It didn't work quite right, so the high speed fuel nozzle inside was changed and the carb became the HDA 48C...A few years later the steel piece on the end of the throttle shaft was lengthened, the carb was then HDA 48 D..

Hi friends, despite your question being MANY years ago, a google search has brought this thread to me ......

I have exact the same isseu with Walbro WT201B original part for DA-50 because the high needle does not feed even all open, enough for the engine to stay in the right spot .

From the second and a half, approximately, the high needle no longer acts, and the engine ends up getting LEAN at high speed ....

After researching a lot, I discovered that it is a deficiency of the original Walbro WT201B carburetor and the FTL52 carb made in China ; Solves the problem . So, here's the hint.

Thank you, petya, my problem exactly. I removed my DA-50 and put it on the shelf many years ago. Can I use a Walbro made for the DLE 55? which I can get from Tower. Do you have any suggestion for how to buy the FTL52?

A Walbro carb from a DLE55 will work just fine on a DA50. But it should be known that DA resolved the WT201 carb problem years ago. I sent my DA50 back for an unrelated problem over 10 years ago and it came back with the carb problem fixed also. I had not even mentioned that problem when I sent it in.

I will call DA tomorrow and make the inquiry. A quick fix costs $35 from Tower and sometimes that is the better route. Thank you, Truckracer.

PCT please give a feedback here about what DA tell you ....

Here is the link for the FTL52 carburetor .....
https://hobbyking.com/en_us/ftl-52-c...-part-032.html

Truckracer .... Do you know how DA solved the problem ?? Since the carburetors are manufactured by Walbro and not by DA .... THANKS !

PCT ... did you call DA ?? Any usefull information ??

Truckracer ??

Just to get registered, today I changed the original carburetor of my DA-50 (Walbro W201B) by an FTL52 (new in bag) that a field friend gave me.

The engine was reborn, the problems with lack of fuel in high speed ended, I made some flights with it, it was reliable, with great transition and excellent performance.

I really can not imagine why a company like Desert Aircraft adopts a carburetor that is not able to provide enough fuel for its excellent engine; but with the replacement the problem was solved.

Best regards to all .

I tried calling but their line was constantly busy. I sent them an email but have not heard back. In the mean time, I have ordered and received a DLE 55 carb which is made by Walbro. I have not swapped out the carb and running it will take a little while since a new 50cc Edge I am planning for the DA will take a while. Very happy to hear that yours is running well!

So how deep do you go. Seems the existing hole only goes to the edge of the brass piece.

Carb issue
 

Not all NO START or POOR RUNNING is carb related. First you should determine if your engine is air tight. If you have an air leak in the crankcase it will cause poor ingestion and distribution of fuel. Make sure all of the screws in the rear of crankcase are tight, If you have a bolt on cylinder this should also be tight and properly gasketed. The carb gaskets must be installed properly and the carb torqued so it doesn't distort the carb flange or gasket, and the crank bearings in the front shaft housing have sealer around the outer portion of the races. If all of these factors are correct then your carb concerns are most likely correct.

I don't know everything about anything but I have been fixing engines of all types for 50 years and the basics tend to be overlooked all the time. Remember suck, squeeze, bang, blow. Each one of these factors have a specific dynamic. If any one of these factors are altered by the least amount it will also alter the desired result.