Gas Engines Questions or comments about gas engines can be posted here

DLE 20 Mid-range problems

Reply

Old Yesterday, 02:16 PM
  #1  
Bad Tooth
Thread Starter
My Feedback: (10)
 
Bad Tooth's Avatar
 
Join Date: May 2003
Location: Livingston, MT
Posts: 228
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default DLE 20 Mid-range problems

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??

Last edited by Bad Tooth; Yesterday at 02:39 PM.
Bad Tooth is online now  
Reply With Quote
Old Yesterday, 06:13 PM
  #2  
ahicks
My Feedback: (2)
 
Join Date: Aug 2008
Location: Waterford, Mi/Citrus Springs, Fl
Posts: 3,657
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

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.
ahicks is offline  
Reply With Quote
Old Yesterday, 06:23 PM
  #3  
Bad Tooth
Thread Starter
My Feedback: (10)
 
Bad Tooth's Avatar
 
Join Date: May 2003
Location: Livingston, MT
Posts: 228
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

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?
Bad Tooth is online now  
Reply With Quote
Old Today, 04:37 AM
  #4  
CK1
My Feedback: (60)
 
CK1's Avatar
 
Join Date: Apr 2002
Posts: 1,305
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

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
CK1 is offline  
Reply With Quote
Old Today, 05:44 AM
  #5  
ahicks
My Feedback: (2)
 
Join Date: Aug 2008
Location: Waterford, Mi/Citrus Springs, Fl
Posts: 3,657
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Originally Posted by Bad Tooth View Post
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?
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
ahicks is offline  
Reply With Quote
Old Today, 09:17 AM
  #6  
speedracerntrixie
My Feedback: (29)
 
speedracerntrixie's Avatar
 
Join Date: Jun 2010
Location: Sacramento, CA
Posts: 6,106
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

With the wings off the airplane there is a great deal more vibration. Could the added vibration be messing with the fuel system?

Another thought, usually when the needle adjustments have limited effect it points to a fuel blockage or something else causing flow issues.
speedracerntrixie is online now  
Reply With Quote

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service