Maybe the low needle is too lean? Is the timing ok? Also what plug are you using? The battery is low or bad? Bad switch? Bad connector?

Yeah, can be anything
Usually engines need to be richened if the weather gets colder.
Also some batteries don't like cold weather.

Though your engine might have been 'running fine', if your engine tuning was 'off' when the weather was much hotter, the cooler weather will certainly help point that out. I'd start with a re-tune and ignition/timing check as suggested above.

Hello I hope somebody can help me here I have a DL50 is about 1 1/2 years old and last week after several succesfull flights the engine don't want to start anymore,this is strange to me because it was running perfect.The only way it wants to start is if I leave the shoke on.

I really need your help to find out what happened.

How's the compression? Any grinding noises? Can you move the tip of the prop back and forward?
If this is all OK it's most likely a carb cleaning issue.

compression seems to be fine and there's no grinding noises I'm aware of.I'll have to check if there's any play on the prop as you said.
I hope it was a carb problem because it never show signs of any problem just finish one flight and it doesn't want to start anymore.

If it only runs with choke it's probably starving of fuel. Clean the carb out. Get a carb gasket kit and maybe replace some parts while you're in there. First thing to check is the screen. Just remove the big screw to remove the pump plate. Under it is the fuel filter screen.

Thanks I'll do that.

Is the large scale DuBro in-line fuel filter sufficient for filtering gas on the plane? Must a felt filter clunk be used even with the DuBro in-line? I have the DuBro on hand, but would have to mail away for the darn Walbro felt filter.

Neoprene vs Tygon in the tank...Tygon seems stiff even new, with a curl in it from the bag. Seems it won't fold forward for nose down attitudes. I guess I want to find some of the neoprene but that means another order for the Hayes brand. Really irritating since I just did a large enough order with Tower for free shipping, and now I find these other needs.

I feel like just trying the DuBro in-line filter only, and the Tygon in the tank with a regular clunk.

i personally do not use a filter between the tank and filter,,to eliminate a cause of air entering the carb,,my filter is on the fill tube,,as far as clunks go and the stiffness of the tubing,,you can use a big clunk or slip a nut next to the clunk for extra weight,,you wouldnt want it to flip forward anyway,during downlines,it could stay that way and pinch off the flow completely,,also it would be asvisable to either use real small zip ties at every connection,,i use snall diateer safety wire ,to secure all my tubing ,also if you like more flexible tubing,just find a dirt bike shop or small engine repair place and get some of that blue stuff thats more flexible,,but putting several filters inline may prevent a clogged inlet on your carb,but also causes more points for leaks and couldslow the flow of fuel ,resulting in less power,,ps i wouldnt reccomend putting a tee on the tank to carb line for filling either ,just use a seperate line to fill ,and you can put a clunk on that one too,so you can drain the tank if needed

ps excuse my typing ,,i should proof read before hitting send,,also secure the clunk,or youll wish you did later when you see it rolling around ,at the bottom of your tank

Don't use neoprene. Do a search and you'll see me and others reporting problems. It just deterorates and plugs up your carb screen. Tygon is fine if you leave some fuel in the tank to keep it soft. I'm going to try Viton for the clunk next time I re-plumb. It stays flexible. I'm using the Walbro felt clunk and a Final filter in line with the carb. This is a system that Jody said works for him and it's working awesome on my DL-50 and DLE-55. I didn't used to use a filter because my gas fill can has two but after all the plugged screen problems I decided to try the Final filter. Works great. It's not serviceable so it can't leak air.

ps i forgot to mention,,make sure that tank has been rinsed out thoroughly before assembling the stopper,and whenever filling let a little fuel flow from the pump first ,incase dust or grit  got ,is in there from prop blastting junk at the field ,before connecting to your tank,,i agree with joe neoprene disintergrates,,incase youre confused,,that little screen shown in the pics above is found in the carb,,once junk gets that far,it causes your to dissemble and clean ,,its weird how our weed whackers never clog up ,but they have a big filter that takes alot of junk before they clog up too.

Great advice to pre-clean all fuel system parts. Even fuel line. I always flushed the tanks with alcohol but never did the fuel line.

Thanks fellas. I guess I will order some felt filter clunks now, and no neoprene. I'll flush out my tank and fuel lines before final assembly of them, and I will add barbs (where none pre-exist) and zip ties on all tubing connections. Jon

BTW the Walbro p/n 125-527-1 is the same exact thing as Echo 13120507320. You may be able to buy either of these locally.

http://www.serviceproparts.com/index...rget=d737.html

I never had my neoprene dissolve to a point it accumulated in the carb screen. I only leave the line inside the tank installed for one flying season, anything outside the tank usually lasts two seasons before I swap it out for new. I rinse it all first, so perhaps the problems seen are from mold release agent or something? In any case, whatever line you choose to go with, don't assume it is the very best and doesn't require routine inspection, develop good maintenance habits early, and you'll keep all of your systems in good shape.

Joe, those are excellent filters! [sm=thumbup.gif]

jedijody,

It has been a wile since this was posted, but I thought I would get back to what I did.
I set the gallon of fuel I had left that was mixed with non oxygenated fuel, and mixed up 2 gallons of fuel using regular gasoline. I fueled up with the regular gas oil mix and readjusted the carb again. The engine ran better with the regular gas oil mix right away. I think the engine still needed some more break in time, because the carburetor still needed some adjusting during the next two gallons. The engine really came in on the 6th gallon of fuel. It was running extremely strong and not as much vibration.
I still had the gallon of non oxygenated gas oil mix, so I figured now that the engine was running well, I would try this mix out again. The engine was right back to rough running, kind of a missing sound, and seemed to load up some. I tried to adjust this out with the needle, but it couldn't be smoothed out. I burned up about 1/2 gallon of that stuff that day and the engine never did run well. I went back the the regular gas oil mix and all was well again.
I guess my engine just doesn't like the extra octane of the non oxygenated fuel. I take it that it was the extra octane that caused the problem?

Greg

No. The additional octane did nothing at all. If you were using Shell gasoline for the oxygenated fuel I can see where the rough running occurred. I've experienced the same thing with their gas in any octane level.

An issue of lost volatiles may have occurred if the oxygenated gas had sat around for a long period of time. Gas retains it's octane additives when it sits but will lose it's more volatile components.

For the guy asking about Dubro filters.

They are absolutely useless for filtering gasoline. Using a felt filtered clunk inside the tank and inside the gas can will eliminate any fuel debris contamination. The Walbro filtered clunks are also a lot heavier than standard clunks and do a much better job of keeping the gas line immersed in the fuel inside a gas tank. Because of that additional weight they even overcome the stiffening of Tygon line inside the tank. Another feature is the felt clunks pick up the last drop of fuel in the tank, break up line bubbles, and don't have to be fully immersed in a fuel quantity to still effectively draw a constant supply of fuel. They only need to be touching the gas.

Too many advantages of using a Walbro filtered clunk to even consider anything else. For those that have a belief they shed fibers and clog carb screens, many thousands of hours of operational use has proven that to be a fallacy. Out of the bag and into the plane.

You certainly called that one, I was using Shell gasoline.

The gas/oil mix was only 1 month old.

Greg

Woo-Hoo! I got something right!

Usually you have a lot higher percentage of right than just "something"

jody, t.o.m, i saw that some engines has the serial number on the front and others behind the cylinder head...is there any reason? just curious?.

If you're talking about a DL50, the only ones with serial numbers were ones sold by Bob Kramer of DLUSA, they were hand engraved by himwith an electric pencil engraver. The case and cylinderwere numbered,I've seen them on the front, or back, I've even seen some with different numbers on the case than are on the cylinder. Bob labeled the 100s he sold as well.

The DLE30s, 55s and 111s are all serialized at the DLE factory and allon the back of the crankcase only.

thanks....i wonder whats the serial number right now...to see how many DLE are around Mine is A2163

p.s. previous post delated...lol i was watching the photo wrong(too bad), mine is on the back lol</p>