Okay, so last week i felt the need to clean out the carb. I have done this once before but just wanted to recheck as i hadn't flown the plane in a while. So i take the carb apart, clean the screen (was a little crap in there), flush out everything, and put her back together. I installed a velocity stack for the heck of it. So i get to the field, i set the needles at the factory setting, or very close (about 1-3/4 turns out on each) And start her up. She starts great, idles great but the high end apears to by reving up and down. Wasn't sure what the reason was so i lean out the low end to try and get the transition better and also lean the high. Seems to be doing okay. So i bring her down to idle and kill it so as to get ready to fly. Start it up. Does fine, but almost imediatley i notice a problem. The engine will not transition at all above 1/2 throttle. It just imediatley dies. So, i seriously fittle with this thing for 2 hours. Take the velocity stack out. Take the engine apart and look in the carb, try flushing it out. Go to start and still will not run above 1/2 throttle. So finally i just try richening it untill the engine will run and low and behold about 3 turns out in transitions fine. So everything seems to be running fine and i am thinking, oh, facotry settings must have been 2-3/4 turns out, not 1-3/4. So i got to take off, start the role and no joke at 8ft in no mans land the damn thing dies on me. Damage so far is a big dent in the wing, broken prop, and a ripped out landed gear. All easily fixable but a huge pain in the but. What the heke is wrong with this thing. What did i do wrong when i took it apart. I sounds to me like soemthing is wrong with the HS needle. I don't know how to clean it out if there is crap in there. I filter my fuel going into the tank and don't see how it can get by my filters and then the carb filter to jam up the HS needle.

Any help would be apreaciated

Cameron

You may check the assembly sequence:
regulating membrane:
Housing - gasket- membrane- cover
The pumper membrane:
housing- membrane-gasket-cover.

Open the idle needle more. The DA50 needs a richer idle. Let it burble in midrange.

It sounds to me that the ignition battery either isn't charged all the way, or is failing.

Ignitions tend to break up when the voltage gets low rather than just fail.

The moral of the story is, if it ain't broke don't fix it This could be anything from improper assembly to possibly when you were cleaning out the carb a piece of dirt got into the H circuit. I would double check assembly and pulling out your needles then clean them from the back side to make sure there is no dirt inside them. A paper clip will sometimes go a long way.

The ignition battery is good. I am pretty sure i have the gaskets and such assembled properly but i can double check that.

That isn't the case all the time. My ZDZ and the DL both will not accelerate when the ign. battery gets too low. My old BME would run terrible when the battery was low.

Okay, just took the whole carb apart and went at with compressed air, WD 40, and carb cleaner. If there was crap in this thing, there isn't stuff there any more. Also, after looking over the plug it looks as if it has been run too rich acording to those online "spark plug picture charts". It is dark black and has a bunch of crap on it. If it is fouled, any chance of cleaning this or should i just get a new plug.

Edit:

I am going to grab another xoar wood prop from chief aircraft. They also have what seems to be the right spark plug. It would be a few bucks more than ordering it serperatly but would like to get them together. Just want to confirm this is the same thing in the Dl

http://www.chiefaircraft.com/rcmsec/...fAircraft.html

You need a new plug. Don't bother with trying to clean it. The NGK CM6 is the plug you want.

Okay, i will do that. I would really like to keep this confined to one order. Notice the pitcure that comes up when you click photo on the link i posted. The plug says NGK Japan. Looks exactly like mine. It says it fits the DA 50 so i am assuming it is the NGK CM6

Cameron

You're assuming correctly

Great, thanks mtwister

Hey guys, i e-mailed bob at DL USA and said that is it possible i invertatley changed the metering valve wich could be causing the problem. I have been really carefule not to mess with it but you never know. Can just touching it mess it up.

I assume you mean the metering diaphram's inlet valve (the little one with the rubber tip, small lever and spring). This can only be changed by slightly bending the little lever or teh spring. Some folks think this setting is a tuning secret, and they go to great lengths setting and measuring "pop-off" pressure. Truth is it's not that critical, and if the lever is sitting as per spec it'll do it's job.

See this:
http://www.geocities.com/farellus/idle_adaptation.html

Hope it helps,

J

1-Make sure you have the diaphram in the right orentation(make sure the nipple is down and the gasket is on the right side. check the meetering level. No trash in or around needle or seat.
2-Make sure you did not overtighten the carb bolts and crack the metal reed housing(check it very closely).
3-Make sure you have a good pulse line going from the carb to the engine.
4-Get a new plug and gap it properly.

Make sure the screws (4 small ones and 1 big one) on the carb, and the carb bolts are tightened. Engine quit when advancing throttle ususally means air leak.

If you have a spare carb, try that one, to rule out the possibility that the internal of the original one was messed up.

All good things to check.Also check no stuff in reeds.Also the reeds have been breaking around here
runs good 1minute same as yours next.Good luck!

You can buy a spark plug that should work as good at http://www.rcignitions.com Capt,n

wish i had another carb to try. After I am done fixing up the plane i will try again and go from there. Everything has been cleaned and tightened. I checked the reeds and the housing really closely. I couldn't find and kind of cracks. Unless it is a micro fracture there isn't anything there.

Ya know, i just might have found why my engine would run so weird sometimes and even abruptly died every once and a while. I couldn't figure out why the carb was so clogged every time i cleaned the carb. Well, i think i found the problem. This could explain alot of problems. I totally forgot that the line that was inside the tanks was this stuff.

http://www3.towerhobbies.com/cgi-bin...?&I=LXRZ80&P=7

I replaced the outside line with tygon soon after so i could see the gas but forgot about the inside. Well, DON'T use this stuff. It was falling apart and there was **** all over the place inside the tanks. Small stuff and very large pieces that could completely stop a line. No wonder all the crap was getting by my filters. Anyway, i have replacced it with tygon and am anxious to try again.

Cameron

I wonder if that fuel line is the same basic formula as the old Sullivan gasoline fuel tank stoppers that were known to disintegrate?

man thanks i better check mine out

Hello, I'm Loetch , 37yrs. plus mech. Fuel systems all eng. and numerous local race eng's. trophy class.I am
lotech because I always look for the easiast first!!! I replied assuming all obvious to me had been checked
Another one for EXP.Glad you found that hose,I have found that many times!And that one still kicks my BUTT.

I hope you have the cure,
LOTECH

This is the good stuff. Plumb your tanks with this and the dark red stopper from Dubro and forget about any troubles for years. Just make sure to divide the clunk line in two with a brass nipple since it's so flexible. I did both of my 50cc gassers with this and they never have problems. Clunk line never gets stiff and it lasts for years. I use tygon outside my tank only. I like to see the fuel in the line.
http://www3.towerhobbies.com/cgi-bin...&I=LXK824&P=ML

[>:]OK,I'm new to net Iwas going to post a qoute but??? I only wanted to say Tygon can last yrs. but
it depends on gas from your st. or country.In ca. I've found that as little as 2mos. Tygon will get stiff
or brittle and break on clunk line. It also happens in my weedwacker if I leave fuel in it!

Cambo - I've been following this thread, and I must have missed the part where you told us there was crap in the carb screen more than once. Sorry if I did.... that black line is pure crap. The stuff Joe Airport linked (Hayes) is the only GOOD black tubing, unless you buy Viton bulk from McMaster Carr or someone.

ON all of my engines and tanks, it is strictly Tygon only, and the more flexible breed/flavor/brand seems to last longest. The more "amber color" tygon, I don't really believe *is* Tygon, but PVC, and it gets brittle, breaks, loosens, etc. PURE Crap.

"Real" Tygon or "Real" Hayes, and your line-related problems will be over.