50 quits when inverted flight, why???

[jharkin]

	Quote: Originally Posted by JoeAirPort
	I thought the carb swap worked, Check out this RCU thread:

I hoped so too, I got the idea from the thread. Seems to work for a lot of folks but unfortunately that fix didn't work for me.

Im thinking of trying the aluminum spacer idea mentioned here. I can scrounge up some 1/8 aluminum to make one pretty easy. I'm ready to try anything at this point....


It sucks to spend so much money on a plane and then not fly it much because you cant trust the motor....

[AHP]

Good luck. I had this exact same issue with a brand new DA50 a few years ago. It would die inverted below 1/4 throttle like clockwork, and was repeatable on the ground. I tried all the tips/tricks/voodoo magic and never was able to resolve it. I ended selling the plane and engine (with full disclosure) to an old circle-flyer that didn't plan on any low-throttle inverted flying - LOL. There was a group of flyers at the club I used to belong to with DA50's that were plagued with the same issue. They used to refer to DA as 'Deadstick Aircraft'.

I do have an older DA50 (serial # in the 2000's) that has NEVER deadsticked on me and runs like a Swiss watch at all speeds and attitudes. It is, however, about 250rpm weaker than my problem-child 50. I'll take that trade off, though! I will say that the best 50cc I've owned/run has a been a ZDZ.

[augusto conti]

dear friends,
I found the solution just throwing away the muffler (da 50 inverted wraparound made by bisson ref.9250) and installing a da 50 inverted ref 9251 made by bisson !
the engine is perfect without richening or leaning the mixture: just changing the muffler !!!
incredible, unbelievable, but true!
and finally, after one year of attempts, the da 50 runs live-stick instead of dead-stick !
best greetings to you all!
augusto conti

[Al Lewis]

	Quote: Originally Posted by jharkin
	Here we go again. Like others I've had this problem on my DA50 since day one also. Like others Ive tried everything - carb plate, carb vent to fuselage, returning, running rich, sending it in to DA (got a bill for replacing the reed gasket, but still deadsticks), and lastly replacing the carb with a DL-50 carb. Nothing ever worked. I can run it rich enough not to die, but as others found, doing that makes the midrange horrible upright. I'm still hoping someday a true fix will be found.... its such a nice motor otherwise

I believe you have to swap out the carb and reed cage.

[80stars]

Guys I started this thread and after trying most suggestions saw no real improvment in inverted engine runs. This off-season I sent the motor to Jeff at DA and let them have a look at it. The engine had close to 50hrs of run time on it when I sent it in and I felt a tear down inspection by DA would be good. They found the bearings were a little worn and replaced both, they also found the carb fuel meter out of adjustment as well as high and low needles off base line. They replaced all engine gaskets and test ran before shipping it back to me. The charge was only for parts and shipping (under 65 bucks) labor and testing free. I have 17 flights on the motor since back from DA and it has never run this good before. Upright, inverted, on it's side, the muffler is the same JTEC pitts wrap, the only thing I changed was the prop. I am using a Vess 23A and 23C, and on my 30% Carden the 23A really lets the 50 sing. My thanks to Jeff and all at DA.

[FlyingFrankie]

Can you guys point me to the information about flipping the DA50R carb? I did that on for my EF Extra and it seems to be running fine, but after reading Scott's post above about flipping it and then sucking a gasket, now I'm wondering.

Also, I too have experienced the inverted flight, engine quitting problem. I lost two airplanes (a Hangar 9 Carden Yak and Comp-ARF 2X2) from low inverted harriers. I sold that motor.

My current engine, running on an RE2 pipe, doesn't exhibit the problem at all. And, it starts first flip, no choke, every time after first flight of day. Finally have the low end rich enough but it doesn't kill the mid with rough four stroking. I'm liking it! Just want to be sure now I won't be sucking a gasket!

[yakken]

i had the inverted problems with my da 50. i ran a tube off the metering plate to inside the fuse and have about 300 flights on it after doing the mod. it runs perfect anyway you want to fly it.

[smokin]

Please forgive me if this has already been mentioned as I have not read the thread in it's entirety....

I had an engine go dead on me several times inverted, as a matter of fact, I lost my Super Extra to it. The problem... fuel clunk tubing that you could pole vault with! LOL

Check that clunk line and make sure it isn't too stiff and staying on the bottom of the tank regardless of the attitude of the plane.

Again, if this solution has been mentioned already, forgive me!

Good luck, better days ahead!

[james.l.hill]

I had same issue with 2 new DA50's and another guy here had just the opposite problem, his engine would go lean inverted and pick up about 1,000 rpm's. My problem was solved by removing the ceramic filter/clunk from the tank, nothing else worked(tube into fuse,ect...). Both engines run fine inverted now at idle for as long as I want. The other guy replaced his carb w/ DL carb and that worked, his was a used engine, mine were purchased new. It does seem that fuel flow is more critical when DA50 is inverted.

[JPal101]

The very same thing happended to me the other day with my DA 50 but more interesting my friend who is flying a DA 85 also had a dead stick in an inverted elevator. I believe it has more to do with tuning than anything else. I am going to richen the bottom end and see what happends.

[Kime]

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[lund-j-h]

	Quote: Originally Posted by Kime
	Is there any solution to this inverted dead stick problem? My DA50 is driving me crazy I have tried every mod what I have seen but haven't got any help. DA just goes lean when the plane is inverted. Do I had to flip the carb 180 degrees to get it lean at normal flight and rich at inverted? This way it won't quit so easy... Yes, this is not a really fix, it's only a "patch"

you have to long breed line on the fuel tank,you got vacum in the tank when the tank is opside down

[Kime]

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[lund-j-h]

	Quote: Originally Posted by Kime
	Are you sure that it is cause of vacuum in the fuel tank? It sounds possible but how it can affect so fast? Immediately after the plane is turned inverted. ...and if the cause is vacuum then engine should quit in a little while but it run just fine above 1/3 throttle or such and can be flyed inverted like 5min or more. Problem is only at idle or bellow 1/3 throttle

i think the problem are the fueltank breed line,
i have that problem with my dle 55 engine the engine quit immediately in inverted
or it can be bad tuning on the carb,or dirt in carb
my breed line go from tank to underneet fuselage ,ca 15 cm long line,no turn arond the tank
and i dont loose any gas i flight

[WOODisGOOD]

	Quote: Originally Posted by Kime
	Is there any solution to this inverted dead stick problem? My DA50 is driving me crazy I have tried every mod what I have seen but haven't got any help. DA just goes lean when the plane is inverted. Do I had to flip the carb 180 degrees to get it lean at normal flight and rich at inverted? This way it won't quit so easy... Yes, this is not a really fix, it's only a "patch"

Make sure that the fitting that is located on the black carb spacer block is pointing the same dirrection as the cylinder. The carb can be rotated 180 degress in either direction. Let me know what you find.