Today I was maidening a 100cc edge with a new DLE 120 on it. It ran up good on the ground, 6100 RPM with a flacon 29x9 prop. First flight, it flew great for 5 minutes, then it died. After landing, it would not restart. We changed plugs, looked at the reeds, made sure it had a spark, etc. The weird part is, you can choke it till there is gas pouring out of the carb and continue flipping and the plugs will be dry as a bone. At no point was I able to get any fuel into the engine from the carb. The reeds opened and sealed up as they should with no cracks in them. Has anyone ran into anything like this before, because even our local engine guru is stumped on this one?

Likely debris in the carb as this was your maiden flight and it ran good for 5 minutes. A bit of dirt in the tank or fuel lines and when it hit those small valves and channels in the carb it clogged it up.

I'm thinking you have an air leak someplace or during that first flight it got hot enough to damage the rings. What I think is happening is that you have enough compression to activate the carb pump but not enough to get the fuel into the cylinders. Try priming through the plug hole while running some fuel with 30:1 oil. If it's a ring issue the added oil will help the rings seal and pull fuel. Look for air leakers around the reed block. The pulse for the carb pump comes from the crankcase before the reed block so the more I think about this, it sounds like an air leak between crankcase Nd carb somewhere.

Thanks Speedracer, that's what I'm starting to think too is an air leak somewhere also. The engine has tons of compression, so I don't feel like it's a ring issue.

I just finished breaking in the Dle 170. Right off the bat I noticed the carb would be dripping fuel and have dry plugs. I went through everything and it was all fine so I commenced to flipping again with the same wet carb dry plugs. Then I went to the DLE website and read the manual, it says "briskly" flip the prop through. So, wondering if maybe I was too slow for it I grabbed the drill with the 3" cone and it started right up. It starts great with the drill but I can't get it to by hand. Just some food for thought.

I tried the drill also, to no avail. My flipping must be fairly "brisk' though because I had no problems at all with a new DLE 170 today. Started great. Thanks for the suggestion though.

Does it still have good compression or even stronger after being ran?
Did you check the reeds with a light?
Did you check the reed base or back, the side that mounts to the engine, on a flat surface with a light? And the side that the carb mounts to?
Have you tried placing hand over carb inlet to see if there was suction? This is an easy way to see if the reeds are working on the intake.
The carb will pump fuel whether the engine sucks it in or not.

Yes, has very good compression.

Ok, so it has compression, it has spark, and gas out the carb. As suggested above, place your hand over the carb with choke and throttle wide open spin it over a few times quickly, this does require a helper. You should feel the suction, if it's light or even has some back pressure then the reeds are not fully closing.

Did you check the filter screen in the carb itself? If you never flushed out the tank with fresh gas to get out the paraffin and excess plastic well when the fuel is pulled in up to the carb it has to go thru the filter screen inside the carb, one side of the carb is the pump and the other side is the filter screen and the diaphragm so be very careful and take your time in taking this part of the carb apart because if you just take screw out and pull apart you can really damage the tiny fingers that sets the diaphragm to the way the engine runs, the diaphragm is more or less what is the needle that meters the fuel thru the carb, but try to check the filter screen inside the carb before you do anything else.

He is getting fuel out of the updraft carb, just not getting sucked into the engine. One of the things I hate about bottom mounted carbs.

Thanks Ace, I'll try that and see what it does.

It takes a bit of a keen ear but by moving the prop back and forth against compression you will be able to hear the reeds clicking. I personally doubt it's an issue with the reeds. My first twin was an old 3W 70. I bought it new but from a friend. Not knowing any better I set out trying to fire it up after getting it mounted in the airplane. On choke it would pop as normal but off the choke it would fire and quit very quickly. Just as I was giving up on it my buddy whom I bought the engine from called to let me know he had removed the reed block and had forgotten about it. So even without reeds you can get the engine to at least fire.

Speed, you know as well as I do that the reeds control the intake. And the reason for the pop and fire without running is the reeds are not closing thus allowing the majority of the fuel being taken in to come right back out. In my opinion your statement is a bit misleading.

Have you tried removing the spark plugs and putting a few drops of fuel into the cylinders, reinstalling the spark plugs and testing to see if it will run?

Got to do that every spring on first start up with my lawn mower. Same thing with snow blower come winter except there I use lighter fluid since it ignites easier in the cold.

The engine ran to start with ,unless the tank or carb was just full of crap I doubt it is plugged off completely however A weak spark can stop it from running , I know you say you have spark but do you have spark under compression??? Spark fuel and air is all that is required, you just need to find the one or ones that is giving you problems. Even if the reeds do leak a little they will still run, but it's an easy check to see if the filter screen has build up on it. Oh just for fun check to see if the Needles are set at (APPROX1-1/2 turns) for a first time start up, then adjust as needed later. You may also try this with the aid of a helper turn the plane over and prime the carb a little, close the choke then return it back to upright flip it a couple of times then open the choke add some fire and see if it will go then.
Just because it's dripping gas out of the carb does not mean that gas is getting up to the cylinder and on top of the piston to burn and fire the engine.

Please tell us what you find and what it took to fix the problem, most curious!

Ace, not trying to mislead, the point I was attempting to make was that even if the reeds were stuck somewhat open the engine would pop. The only way it could be a reed issue would be if they are stuck closed. I have not ever seen that happen. I'm still feeding to there being a large air leak. I would pull the intake assembly apart and take a close look at the gaskets. There should be visible signs of leakage on one of the gaskets. If it were weak spark the plugs would get wet. IMO there just is not enough crankcase velocity to get the charge up into the cylinders. An air leak or poor sealing rings are the only items I can thing of that would do this. Unless the needles are set way lean and the metering needle is stuck in the open position.

Put a few drops of fuel in each cylinder via the spark plug holes. Open the throttle wide and st art flipping. If it does not rfire and run out t5he charge when your arm gets sore its an ignition problem.(you said it had good compression).
If it fires and runs out the charge you have a fuel problem. If fuel runs out the carb while choking your carb jets are plugged. If it were a crankcase seal problem or bad reeds you would not get fuel to come up while choking.

An easy way to check your rings is to trot down to the local auto store and get a compression checker.If you run big engines its a nice tool to have

Holy cow! Did you actually suggest that he try to start a misbehaving 13 HP engine with the throttle wide open?

I have had problems with several DLE engines that would start, run and die, then not start again. all of them had a clear, gooey, substance in the carb, These were all new engines. This was not from my fuel, or tanks. Use spray carb cleaner, pull fuel screen and needles, spray all holes, ports well with the cleaner. The carb would pump gas but none would get to the cylinder. I now dis-assemble all of these carbs and clean before running them.

I know, just clarifying for those that don't. On DLE's with the updraft carbs the reeds do not need much gap for insufficient suction. Most of the updraft reed blocks I have seen appear to have a rough finish to the surface. I just got home from a friends house where I just fixed his brand new, has not been run, DLE 170. Same issue in regards to starting, first thing I did was pull the carb and reed block. I placed the reed on a piece of black glass and with a flashlight one can see light around the perimeter. Sanded the reeds on the glass, which has 800grit on one end, and wah-lah it starts on the third flip.

Yes. If he does not have proper restraint he should not be trying to start it.

How about if the engine does not start by normal means then stop trying, fix the issue and resume in a normal high idle start setting. Would this not be much safer? How does one know his restraint would hold up to 60lbs of thrust. How about the part of the airplane that the restraint is connected to? What about the possibility of the engine mis-firing at full throttle and shearing all 6 prop bolts and spitting a 28" prop in your face? Remember most accidents happen when people start working outside the norm.

I think Ace has a great suggestion, pull the intake apart, true up the reed block. Assemble with no air leaks and try again but in a normal starting mode.

it would be safer to fix the issue first provided you know what the issue is.
I would think you would like to make sure the restraint is good for what it will produce before you start messing around. There are always possible problems that could make it go to full throttle by accident.
I really dont think his problem is the reed bank. Needlessly messing with that can do more harm than good.