ORIGINAL: nikonlarry
<p style=''margin: 0px; ''>Thanks to everyone for all the information. These forums are a great source of information. I just want to make sure I have it correct.</p><p style=''margin: 0px; min-height: 14px; ''>
</p><p style=''margin: 0px; ''>There are two behaviors that people have been discussing here. Hanging and step.</p><p style=''margin: 0px; min-height: 14px; ''>
</p><p style=''margin: 0px; font-family: Helvetica; ''>Hanging: As I understand it from reading is that the #4 version of the ignition module has a control programmed to hold the RPM up for a while when you throttle down to allow the prop to cool the engine since the ambient air will not cool the engine when the plane is flying slow. This can be a problem when coming in for a landing when you throttle down and the engine does not return to an idle in time before you run out of runway. This is not a problem that will cause the engine to die if it is tuned correctly. If you have the #4 ignition module you can replace it with the RCexl module which will work with most all DLE engines. The replacement is only needed if this hanging is bothering you. One question is what DLE engine models have this built in. DLE 20cc for sure but what about the DLE 30, 35, 50 55 etc. </p><p style=''margin: 0px; font-family: Helvetica; min-height: 14px; ''>
</p><p style=''margin: 0px; font-family: Helvetica; ''>Step: Is this the point when the timing advances. Do I understand that the timing advances fully at around 2200. And there is not really a curve. This can mean that if you advance or retard the throttle the engine can jump RPM up or down. Is this just ignition module #4 or all modules. Also only for DLE 20cc or all sizes. If tuned correctly then this is just a behavior that that will not cause the engine to die or cause any other problems.</p><p style=''margin: 0px; font-family: Helvetica; ''>
</p><p style=''margin: 0px; font-family: Helvetica; ''>Thanks larry</p>
Larry
Your post is a perfect example of mis-information.
I'm I able to make this more clear, I'll give it a try:
The DLE 20cc engine comes standard with the DLE #4 module built for DLE by RCexel.
The DLE 30cc & 55 comes standard with the DLE #1 module built for DLE by RCexel.(these are the only engines I bought new so I can verify only these three).
Of important note on these two ignitions is that the #1 module has Bill Carpenters auto advance ignition timing built to simulate a steady mechanical advance. While the #4 has a single setpoint all in timing advance.
Here in the market we are not privelge to why this was done. Only that some users of the 20cc have a difficult time with this
Now I have to speculate here a little from my field observations.
Many new to gas engine users have come into the market. Your post is an example of some of the mis-information some of them have.
In the #4 there is no program to hold the engine at an RPM for cool down(cool down is best achieved with a slightly rich LSN). The program simply calculates the RPM and retards it below a setpoint or advances it above the set point.
If you add in the problems of learning to tune gas engines along with the power production vs butterfly position and now the "STEP". All things new to gas people do not understand yet.
You can see where much of these issues get their facts distorted. However in this long thread somewhere is almost all the information anybody will ever need on this 20cc engine. Much of the most useful info is update on the first page.
A properly setup and tuned engine no matter what should not die.
I hope this is clear. Any questions please ask.