Bad Tooth

My Feedback: (10)

Hi guys, I have been reading through a lot of threads that deal with DLE 20 problems but haven't found an answer to my problem yet, so I thought I would start a new thread.

Brand new DLE 20
Xoar 17x6 prop
A-02 ignition
4.8v ignition battery
NGK spark plug
Fresh fuel 32:1, 91 octane (no ethanol)
Using a starter
Carb needles (H,L) are close to factory recommendations
Running mounted to the airframe with no wings

Here's what's happening:
To start it: close choke, throttle open, turn over a few times with the starter. Open choke and throttle at half throttle. It takes a bit with the starter but it always starts after this.
It runs fine above half throttle. Transition is good from half to full and even idle to full as long as I don't hesitate moving the stick too long. If I go straight to idle it seems to idle fine. I notice idle and WOT changes as I lean or richen the mixtures. It'll run all day above half, and idle all day at idle.

If it sits at idle too long and I try to advance the throttle - it dies
If I get down to half throttle and slowly decrease the throttle - it dies - shortly after passing half way.

I haven't seen any change in these symptoms adjusting the needles, it always seems to be the same no matter what I do. Won't run between 1/8-1/2 throttle.

Any ideas?? Ignition??

ahicks

My Feedback: (2)

Not crazy about the 4.8v plan (prefer 6v+), but it should be OK, especially if you're OK on top end. If the voltage were sagging, it would go into limp mode, and never deliver more than about 25% power, while sounding like it's got a major carb issue.

From what you're saying, my bet is you're too lean on the low speed. That engine should flip start easily. The fact yours is balky even with a starter is a big hint.....

The richer low speed setting will force you to open the throttle a bit to maintain idle rpm. Doing that increases the airflow over the tiny idle jets in the carb bore, which will effectively make the engine noticeably more forgiving where you are having trouble.

Bad Tooth

My Feedback: (10)

Thanks ahicks. I didn't mention but I did try switching the ignition battery to 6v which didn't seem to help.

The recommended position for the L needle is 1.5 turns out. I feel like I tried to move that thing a lot! Anywhere from 1 turn to 2.5 turns out. Do you think I should just keep trying to richen the low needle?

CK1

My Feedback: (60)

I agree with ahicks about running the low needle a little more rich . I would also add that until the engine breaks in more you probably will have some mid range roughness and some throttle transition issues. Get a reliable idle and reasonable transition and just fly it to get it a bit more broken in . When the rings seat and the friction reduces you will be able to get better needle response and better performance

ahicks

My Feedback: (2)

Agree with CK1's comments 100%.

I just wanted to add those 1.5 turn out settings do nothing but assure the engine will start. If yours actually run best set that way, it's just luck/coincidence. They are in no way meant to be indicators of where the needles should be when properly tuned. Once started on the initial start, you need to tune the engine for the conditions it's running in. This will involve setting peak rpms at wide open throttle, then richening just slightly until you hear the rpm drop, then go to your low speed setting for proper idle and transition after doing that. Note that the mixture the engine is is running on is actually a combination of the fuel through the low and high systems at any given time, so you may want to recheck your high speed setting after setting the low to make sure it's still OK.

Only after all that is done are you ready to make the necessary tweaks required to really get the engine dialed in. -Al

speedracerntrixie

My Feedback: (29)

Bad Tooth

My Feedback: (10)

I read something about running with wings on being important. I'll plan to put the wings on next time.

"Another thought, usually when the needle adjustments have limited effect it points to a fuel blockage or something else causing flow issues."
I thought it seemed like a blockage too, but could it just affect the 1/8-1/2 range?

I will try to fatten up the low end needle when I start it up again.

I have another question. In my search for answers I watched one of DLE's videos last night. They said in one of the videos if you pull the plug to check for spark you should always touch the plug to the head when you turn the shaft. I did check for spark when I first got the engine but I didn't touch the plug to the head as I turned it. The video said this could damage the ignition. Did I fry my ignition when I did this? Or not a big deal?

Thanks for all the help guys!

ahicks

My Feedback: (2)

Thankfully the ignition is pretty sturdy on these things. The potential to damage the ignition is greatest when turning it over with power to the ignition on and NO spark plug installed. The spark that's created in that situation has nowhere to go, and it's strong enough to use it's imagination finding a place to ground. Unfortunately, that's often through the pick up/sensor, whose components are not rated to handle that kind of power, making it kind of a weak spot. Generally those are pass fail, so I doubt seriously yours is damaged or causing your problem.

If the plug is inserted in the boot correctly, the metal boot and braided wire attached to it act as a ground (all you need). You do NOT need to touch the plug to the cylinder for a ground.

As far as restrictions, your engine is idling well, and seems OK at wide open. For me anyway, I struggle with the idea of there being a restriction.

Wing on the airplane only to minimize the fuselage dancing around, especially while on idle. The wings dampen that rocking motion caused by the single cylinder engine.

If you haven't done it yet, you need to establish a base tune (procedure to do that described in my last post) prior to any further "tuning". Reason being, you need to get the fuel flow balanced between the low and high speed circuits. You want the high speed circuit supplying the majority of the fuel when running wide open, and the idle system supplying the fuel on idle. The ONLY way you can do that is to establish a base tune. If this seems contrary to your thought process, there's another totally different way to adjust the carb that uses completely different logic. It no easier by any imagination, and it does not change the end result. It still requires the engine to be run at wide open throttle as part of the process. If you'd like to know more about it, send me your email via PM. This site will not allow us to post links to other sites, even via PM. -Al

Bad Tooth

My Feedback: (10)

It's running! I tried it again and just kept turning the L needle out until it kept running. I think it's out about 3.5 - 4 turns.

Thanks again guys, you all were spot on! I'm kind of on an island where I'm at. Not many fliers in the area and distance between the ones that are here. I usually fly alone off of a landing strip in our field. So not many people to ask when I get stuck on something. This is only my second gas engine. I can't recall a glow engine being that far past "recommended" needle settings (for cars or planes). I'm glad it wasn't a bigger problem.

Now I just need better weather to fly the thing.

Have a Merry Christmas everyone!

CK1

My Feedback: (60)

If your needle adjustment is that many turns out you may need to check the inlet screen to be sure it is clear of debris and or film . The screen can look clean but may be restricted with a buildup restricts flow . Take the screen out and use spray carb or brake cleaner through it or replace it with a new one . Also check the metering lever height . If the lever height is too low it will cause a need to run the needles out more than usual .

the Wasp

My Feedback: (1)

maybe this thread will help

http://www.rcuniverse.com/forum/gas-...engines-2.html

Jim

ahicks

My Feedback: (2)

With the hundreds and hundreds of these engines that are running just fine out of the box, I struggle believing there's an inherent design problem. I do think that the string Jim's referencing above does point out a potential problem regarding our OP's issue. There's a good chance the spring tension or lever height in this carb is incorrect, forcing the LS needle to be open that far. That leaves some options.

1. Just run it. If there are no issues and the engine handles OK, we're good.
2. Some may try to adjust the lever/pop off pressure to bring the low speed needle setting back to normal, but knowing exactly how tedious this job can be, this option is not going to be for everyone.
3. Buy a new carb. They aren't that expensive.
-Al

Truckracer

My Feedback: (19)

Another option: Warranty!

I know of no known inherent problems with the DLE 20 as produced over the last several years. Early ones had some problems as noted but these issues were corrected some time ago. Now a darn good little engine in my opinion but so many people want to point their finger to the past issues.

the Wasp

My Feedback: (1)

don't take it personal

Jim

Bad Tooth

My Feedback: (10)

Well, I started it again today (just for more break in time) and it runs bad again..... Didn't touch the needles. This time it won't wind up at wot but it would stay running. It would idle pretty well but at about 1/5 throttle. If I put it all the way down where it was idling well 3 weeks ago it dies quickly. I checked my throttle linkage and can't see where anything changed. Mid-range was ok today. It's like someone changed my needle settings when I wasn't looking!

It seems like something is clogged? Idk, maybe I should check out the warranty?

karolh

Happy New Year.....sent you a PM.