RCU Forums - DLE 20 wont come down to idle

RCU Forums (https://www.rcuniverse.com/forum/)

- Gas Engines (https://www.rcuniverse.com/forum/gas-engines-142/)

- - DLE 20 wont come down to idle (https://www.rcuniverse.com/forum/gas-engines-142/11646034-dle-20-wont-come-down-idle.html)

DLE 20 wont come down to idle

Does anyone else have a problem with any DLE 20's taking a long time to get back to idle speed after rev up? I have a DLE 20 in a Hangar 9 P-47 and it just takes a long time to get back to idle after coming back down on the throttle. It does eventually idle down but it is taking a long time. I have tried leaning the low end, richening the low end. Checked the carb for dirt, etc.. Cant figure it out. anyone have any suggestions? Thanks

Though you could possibly have a a cooling issue, a lean condition would be the more common issue by quite a bit. You aren't far off though. Richen just a hair at a time until the condition goes away.

If the carb tuning doesnt resolve the issue and you have eliminated all possible air leaks know that some of the early production DLE 20 had an ignition module with a strange advance curve. The timing would hang in advanced timing at lower rpms just above idle . A new ignition from Rcxl or Rcxp should reolve the problem . If you have a newer engine less than a few years old check the throttle butterfly for proper positioning in the throttle bore. Be sure to remove the idle stop screw in all cases.

As ck1 stated there may be an ignition issue. Check your ignition box for the model #. If it is the #4 A-01 version that may be the problem. Check and let us know which version you have. Later A-02 versions should be ok.

CK1 and Truck Racer hit the nail on the head....I had one of those early models.....either plan for it to return to idle or purchase a newer ignition module.

If it is actually one of the "problem child" first generation modules, there's a tell tale voltage rating of 4.8-6v on the label. That's pretty much a positive ID. If it's rated to 8.4v, that a positive indicator it's NOT one of "those" modules.

There were a lot of us that ran those successfully. I still have one in use, running on straight LiFe voltage. The trick to these is realizing that single step electronic advance curve happens at about 2200 rpm (or so). So if you are trying to drag your plane in on final at about that rpm, it's not hard to see your rpms are going to be wandering around.

There are/were MANY who could not understand that issue (or didn't want to be bothered with it's potential issues) and replaced the module. Many more struggled with the concept of the "high idle hang" issue described above which confused the issue because their problem could be either issue, or both! Gas rookies are/were often confounded by the potential for either condition.

The trick to running that early module successfully is to keep low speed on the rich side, and keep the idle set at something under 2000 rpm. OR, run the low speed on the rich side, and replace the module. Your call.

ahicks, Very good explanation. Had one of these myself back then.

Agree 100% with ahicks on how one can live with the A-01 #4 ignition. An engine guy can get along with that ignition just fine. But I'm one of those people that would just prefer to replace the ignition with one that has a normal advance cure and not have to worry about the problem.

My friend has an early DLE20 with one of those ignitions in a CUB. It runs very well on one outing but then the next time he brings it out, he gets the idle hang problem and has to tweek a few things to get back to normal again. He isn't a patient engine guy and cusses the thing every time he has problems. I've suggested he buy a different ignition but he's too cheap for that so I guess he'll continue to have problems. I would have replaced the ignition long ago and just enjoyed to airplane / engine w/o the problem child ignition.