O.K. here is the problem, got my DA50 back from DA last week with a brand new ignition box, (and before anyone ask it does have all updates etc and the motor has 5 gallons through it and now I am running 100:1 amsoil),, ok, I left the needles alone at wear DA had them which is probrably factory settings????????? I am in North Carolina they are in Arizona??????? anyway, first flight, I took off motor burbled somewhat through midrange, I would give it full throttle and it seemed to run fine, even on up lines, but when I would through it in a quick Knife edge either way it would act like you cut the ignition switch off(it cut off that quick), I could level out right quick and it would catch back up,,,, and when I would go upside down it would also try to cut off,,but in level flight it ran great, now after the first flight of the day it quit doing that which is weird???????????????????????????????????????/ O.k next 3 flights when I would throttle back it would cutoff ,, it did it twice on final approach and one time I was doing a harrier and it cutoff,,,, ???????and finallyon the 5th or non 5th flight,,, I was going to fly it again,, and I tried to crank, (with choke off) and I would flip it with the throttle at idle and it would start for about a second or two and cut off and it would do this for about 3 or 4 trys and then it would not fire anymore until I choked it again, in which it would only flood and not pop,,,usually it would pop with the choke on and then I would turn the choke off and it would start on the 5th flip,,,,,,,, does this starting problem possibly have something to do with it cutting off in flight at idle, is the low end to lean or rich, is it loading up these are the things I am not familar about,,,,, if anyone has any suggestions please help,, thanks in advance,, P.S. it is on a Wildhare Extra300 special, I have a 1100 mah NIMH 4.8 volt battery on ignition,,thx

i had simular problem today cheak your clunk and line in the tank had same problem
have a look at my post
http://www.rcuniverse.com/forum/m_39..._7/key_/tm.htm

It doesn't act like the clunk to me ,,, unless I am not understanding,,, When I rolled it to a knife edge it was a instant cut off, if the clunk was the problem wouldn't it take longer to cut off, instead of instant cutoff, ??????????????????????????

Call DA- possibly-- a problem with the carb pulse line/position.

Burbling in mid-range and quit after throttle back usually imply a rich low needle setting. try to lean it to 1.6 turns out.

Difficult to start after a few flights is an indicator that the ignition battery should be recharged/cycled. It happened to my 5-cell nicad ig. battery. Recycling solves the problem. Also make sure the ignition module's box is not completed wrapped in foam.

--qc

I have a friend who had the exact same problem last week. We messed with it for hours. He finally took the plane home and went through the entire fuel system and found that the very tip of the brass tubing coming out of the fuel tank (carb feed line) got pinched about half closed. Check every fuel line and brass tube to make sure they are clear.

Good Luck

I checked the ignition battery and it showed 5.00 volts,,,could this not be enough voltage????????and it sounded rich in the air, but wouldn't the way it wouldn't start make it sound like the low end was lean,, DICK HANSON WHAT IS YOUR TAKE ON THIS,,,

Your at about 100' above sea level. Maybe 150' at best.

Da is in Tucson Arozona. Elevation 2390' above sea level.

Why wouldn't you just tune the engine for best running at your altitude? It's not going to run right at 100' with the same needles from being adjusted at 2390'.

Did the guys at DA adjust it? Or did they NEVER touch your needles? If they touched your needles to test the engine at their shop--then it's all whacked out for your altitude. Adjust it.

I don't understand the reluctance to adjust the needles on a gasser. I read post after post from poeple asking for factory settings on a gas engine. And I read post after post from people who claim to be running their engine for break in without ever adjusting the needles for best runing at their altitude.

Is it voodo? Black magic? Witchcraft? too adjust the needles on a gasser?

Tune the damn thing to run best at your altitude. Doesn't mater if it's brand new or got 1000 gallons through it. Just tune it.

jongurley,

Lots of good advice so far in this thread. Double check and make sure your fuel system is ok. Chances are if it was alright before you sent your DA back, it's ok now.

Gotta set the needles...........Don't be afraid to turn them, especially on the DA50. I HAD two of these so I've had my share of tweaking needles trying to get them to run right that's for sure.

Here's how I would set the needles.....

Close both needles all the way. Open the high 2 turns, and the low 1 3/4. Crank it up and go to full throttle. If it doesn't burble at full throttle, leave the high there. Now pull back to idle and see if it will idle for 20 to 30 seconds without dieing. If it does, lean it 1/12th turn, crank it up, go full throttle to clean it out, then back to idle. Just keep taking the low in until you can get an idle for 20 seconds or so without it loading up. The high speed needle really doesn't do much on these engines. Two turns out is wide open, going to three turns won't let anymore fuel through. I never did get my engines to run right while flying inverted at 1/2 throttle or less. They always loaded up, especially in an inverted harrier while at 1/4 to 1/3 throttle. I tried velocity stacks, venting the diaphragm cover to the fuse, and tweaking the low needle till I was blue in the face. By the time you get the low needle lean enough to where it doesn't load up on you when inverted, it's too lean in upright flight.

I also had trouble with hot restarts. I fly by myself a lot, so it's fly a 15 minute flight, land, sit for 10 minutes and fly again. During warm weather, the only way I could start my engine after a 10 setting period was to have a 10" fan blowing into the cowl to cool the engine off. No kidding.......got an inverter in my trailer and that's what I would do. If you restart right after landing, it was ok. Sit for 10 minutes, and it would act just like you were describing. Choke, couple flips and it would pop, but couldn't keep it running. If it did start, it was real lean and most the time it would die after 10 seconds. Richen the low needle, then you're right back where you were with the rich inverted flight characteristics.......I put the fan in front of it, and it solved all my restart problems. I think the heat was building up and causing a vapor lock somewhere in the fuel system.

Your battery voltage is not the problem. One time I accedentally flew mine down to 3.8 volts and it was running fine.

There's talk now of adjusting the pop off pressure in the carb. I never did try this to solve the loading up problem while inverted. IMO when DA had to change the pulse line from the crankcase to the reed valve block to keep fuel from pooling there and loading up at idle. Well where is the pulse line at when you fly inverted?????? Yep, it's on top and now fuel is pooling in the bottom of the reed valve block when you are at lower throttle settings. It doesn't effect it while at higher throttle settings.

I gave up and sold both my DA50's before they cost me a plane by flaming out low and inverted. Bought a stock G62 for the WH Extra, runs perfect, no loading up while inverted........nadda, never. Running a 3W80 in a AM 33% Yak. First 3W I've ever had, and it won't be my last. Tilltoson carb very easy to adjust, no midrange burble, easy restarts, and no loud rattle when running.........

Someone here on RCU had a 3W that was loading up on knife edge, he made a small 1" square box out of balsa and ran the carb plate vent line into it. Solved all his problems. That's what I would try with the DA50.

Let me know if you ever solve the problem...........

NOGYRO, I appreciatte the response, I will tune the engine properly tonight, and will it hurt to do the carb plate brass tube mod anyway, and I take it I just take a brass piece of fuel line size tubing bend it to a 90 degree and solder it to the carb plate, and just run a piece of fuel line in a box in the fuse,, correct!!! ...
P.S> RCPILET, I am not a betting man, but if I had to put money on it, I bet you are Divorced,,

No, I'm happily married to a fine woman who is also happily married.

If my response sounds harsh--then good. It came out exactly as I wanted it too. Why anyone would be scared to adjust their engine is beyond me. You should have learned how to properly adjust a carb long before you got into gasoline engines. Gas engines aren't voodo. If you don't know how to adjust the carb, or you can't tell the difference between lean and rich--then get an electric plane.

Funny, I told you to adjust the engine, and you didn't like it. NoGyro told you to adjust the engine, and your following his advice.

Whatever dude.

Have fun screwing with your DA. I gave you sound advice. You may not have liked it, but it was sound advice.

I'm outta this one. Have a good time.

,,, told you guys he is divorced,,, anyway,, if anyone has any pics of the carb plate mod, I would greatly appreciatte it,,

It won't hurt a thing to go ahead and do the carb plate mod. Just run the fuel line into the balsa box. The balsa box can be in the fuselage or in the engine box, doesn't matter.

I sent you pics of the carb plate mod to your email addy.

This is how I solved a pressure problem with a 3W (answer to qustion posted), don't know if it will help your problem out but like nogyro said. It won't hurt anything.

http://www.rcuniverse.com/forum/m_4380953/tm.htm

start at square 1.
tank - No filter in tank or line - No fill valve in system
use a T and fill then plug fill line .
be sure clunk moves freely AND that there is no leak at clunk line in tank.
next
start and adjust for idle that will recover from idle easily
set for full power then back off a 1/8 or so
Do NOT just run it on and on and on the ground -
next
before you even attempt to fly it
with it running at low power- pick it up and rotate it to knife edge . have someone watch your TX!!! be very careful here --
If it kills when rotating it --stop the test - you are somhow getting puddling at the pressure port in the backplate .
If it still runs OK -roll to inverted in th air -at safe altitude- and do a smooth outside push maneuver -- it should go thru this without conking out.
It may change rpm -but not much
If this kills it - land - then adjust high end a bit leaner but never sagging lean try again.
Ignition on a good NiMh at 5V is fine forget all that fancy stuff- one GOOD MODERN 4.8 1000ma Nimh is going to give full performance for the whole day.
Irun ZDZ for my own planes -choice- but I have run/ setup/ done reviews on DA - good engines - somewhere you are missing a basic setup thingy
My crystal ball is about used up at this point of check out ideas.

Thanks NOGYRO and RTK, the weather here in North Carolina this afternoon is stormy, but I will pick up the brass tubing and such to do the mod tommorow or wendsday, anyway , I will keep you guys informed, and as always if anyone has any thoughts or comments bring them on,, I believe a thread like this will benefit abunch of people, and save some questions in the future, ,,,

Nogyro,

I used to have difficult-to-start-after-a-few-flights problem that you described, the solution I found was to not wrap the ignition box completely in foam. Rather, I just allow a layer of 1/4" foam between the box and the wall of the firewall. All other sides of the box is exposed. This solution was tested in central texas where the temperature in June-sept. can reaach 100 in afternoon.

Hope this helps. --qc

Hi Jongurley,

If 5.00 volts is tested under a load, the battery probably is fine. The load should permit a 600ma current draw.

My experience tells me that DA50 will remove about 180mah from the battery for each 10 minutes flight. Since I am using Nicad, it develops memory. Heat inside the cowl after a flight is another contributing factor to the problem you described. This is specially true in central Texas during summer!

--qc

Thanks for the suggestions DICKHANSON and nonstoprc,, O.K. since it is storming and raining like crazy here in North Carolina I took and did the carb mod just a minute ago, don't laugh at my mountain of solder I was by myself so I had to get buy, I soldered over the side hole in the cover and drilled out a middle hole in which you can make out(poor quality pics) the brass tube, then I built a small 1-1/2 ??? balsa box and mounted it in the fuse,,, I took and sealed the fuel hose into it,, anyway pic one is my mountain of solder and the brass tube, pic 2 is the box mounted in the fuse,, tell me if I did something right or wrong I think i is par everyone elses but I am not 100%..

As long as you did not solder the hole closed on the brass tube you are good to go. Let everyone know how it all turns out.

I like the balsa block idea..definitely let us know how it works..

Will do,, I took and put a small drop of ca to hold the brass onto the plate dead center,, I then got a drop of solder on it, and then I just went to town soldering I first of course roughed both the plate and the brass tube with a dremel I then soldered and let cool then I tried to pull out and it was dead solid,,, the I just built in about 2 minutes the balsa box and put the tubing into it and put RC56 canopy glue around it,,,,,,

Im thinking that (balsa box) may be the reason mine didnt work as well..I just ran the tube into the middle of the fuse..

Is it possible that the inside of the fuse can pressurize and cause the same/similar problem as the inside of the engine cowling (pushing on the vent side of the diaphragm)? Whether or not there's a box around it? The more air speed the plane has the more air that can go inside the fuse to pressurize it? Just an idea, I could be totally wrong.