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

Rcexl sensor problems

Reply

Old 09-19-2015, 06:32 PM
  #1  
CARS II
Thread Starter
My Feedback: (7)
 
CARS II's Avatar
 
Join Date: Oct 2002
Location: Sacramento CA
Posts: 5,065
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Rcexl sensor problems

Ok
I've been learning about timing, my DLE 35RA has a timing of 46 degrees from factory, I recently checked the timing out of curiosity and found it timed at 46 degrees, on the other hand I turned the shaft the opposite way and it sparked at 26 degrees.

There is no way I can make the timing 28 degrees since the sensor bracket can't be move, I was wandering if the factory timed the engine rotating the shaft the opposite way.

The engine runs good at that timing, the question here is will this engine run better if set at 28 degrees? and should it be re drilled to be able to move the bracket?

Any suggestion or recommendations?

Thank you.

Last edited by w8ye; 09-25-2015 at 10:56 AM. Reason: Title change to reflect the true subject
CARS II is offline  
Reply With Quote
Old 09-19-2015, 10:46 PM
  #2  
CARS II
Thread Starter
My Feedback: (7)
 
CARS II's Avatar
 
Join Date: Oct 2002
Location: Sacramento CA
Posts: 5,065
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Also out of curiosity I timed my BME 61 twin cylinder engine, it is timed @ 28 degrees exactly to the degree, this engine is about 8-9 years old, has a CH ignition and it is at its best even after been use to race a Spitfire before.

To time the engines I used a buzzer from HK, the timing wheel from CH that you can print from Adrian's web site and also did the spark plug sparking thing, when I was timing the DLE 35 I noticed that the spark came early, the magnet was beginning to go under the sensor when it buzz or sparked ( did it both ways to confirm ) I also noticed that the buzz was long, from the moment the magnet was beginning to go under the sensor to the moment it came out on the other side of the sensor. When I timed the BME it was a short buzz and at 28 degrees.

From what I have learned from adrain at CH, the spark has to come just after the magnet is moving from under the sensor, also read somewhere here that the sensors that comes with the DLE engines are not the best.

Any comments?

Last edited by CARS II; 09-21-2015 at 06:43 PM.
CARS II is offline  
Reply With Quote
Old 09-20-2015, 04:43 AM
  #3  
Whiskey Bravo
My Feedback: (31)
 
Whiskey Bravo's Avatar
 
Join Date: Feb 2002
Location: Waterloo, IA
Posts: 190
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

I think yours may be set at 26 degrees as indicated in your first post. My latest DLE 35RA checked at exactly 30 degrees using the same HK product as you. I left it there and it runs great.

Last edited by Whiskey Bravo; 09-20-2015 at 05:37 AM.
Whiskey Bravo is offline  
Reply With Quote
Old 09-20-2015, 05:09 AM
  #4  
Indiomike
My Feedback: (5)
 
Indiomike's Avatar
 
Join Date: Feb 2008
Location: Indio, CA
Posts: 376
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Originally Posted by CARS II View Post
Ok
I've been learning about timing, my DLE 35RA has a timing of 46 degrees from factory, I recently checked the timing out of curiosity and found it timed at 46 degrees, on the other hand I turned the shaft the opposite way and it sparked at 26 degrees.

There is no way I can make the timing 28 degrees since the sensor bracket can't be move, I was wandering if the factory timed the engine rotating the shaft the opposite way.

Indiomike

The engine runs good at that timing, the question here is will this engine run better if set at 28 degrees? and should it be re drilled to be able to move the bracket?

Any suggestion or recommendations?

Thank you.
I think some of the confusion to the proper timing point comes from what you mentioned in your first post. If you check timing by turning the prop in the normal operating direction ( counter clockwise while facing the motor from in front of the prop) you will be close to the 28 degree mark. But if you turn the prop clockwise while facing the motor from in front of the prop, you will get the 46 degree mark give or take a few degrees.

Just about all the guys who really know 2 stroke engines will say that proper timing will be 28 degrees BTDC. Two to five degrees either way from 28 degrees won't make a huge difference in engine performance.
Indiomike is offline  
Reply With Quote
Old 09-20-2015, 10:29 AM
  #5  
Truckracer
My Feedback: (19)
 
Join Date: Apr 2004
Location: Des Moines, IA
Posts: 4,955
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Originally Posted by CARS II View Post
Also out of curiosity I timed my BME 61 twin cylinder engine, it is timed @ 28 degrees exactly to the degree, this engine is about 8-9 years old, has a CH ignition and it is at its best even after been use to race a Spitfire before.

To time the engines I used a buzzer from HK, the timing wheel from CH that you can print from Adrian's web site and also did the spark plug sparking thing, when I was timing the DLE 35 I noticed that the spark came early, the magnet was beginning to go under the sensor when it buzz or sparked ( did it both ways to confirm ) I also noticed that the buzz was long, from the moment the magnet was beginning to go under the sensor to the moment it came out on the other side of the sensor. When I timed the BME it was a short buzz and at 28 degrees.

From what I have learned from adrain at CH, the spark has to come just aftr the magnet is moving from under the sensor, Ialso read somewhere here that the sensors that comes with the DLE sensors are not the best.

Any comments?
When turned in the normal direction, the spark occurs after the magnet passes under the sensor and just passes away from the sensor. The spark occurs when your beeper turns OFF, not on. This will usually be when the magnet has passed under the sensor and is about half visible as it passes away from the sensor. Many people think the spark occurs when the beeper turns on and this is not the case .... though there is one exception .... see below.

There have been some defective or incorrect Hall sensors used on various engines. When connected to an ignition, these may trigger the spark once as the magnet first approaches the sensor then again in the normal location as it passes away. Connected to the beeper device, they act normal. This is the so called "double spark" problem that has been discussed in various forums and can only be resolved by replacing the sensor with one that doesn't exhibit the problem. This problem causes hard starting and poor acceleration though the engine will run. Many people that have this problem will blame the carb for the problem when the issue is really ignition related. Its difficult for the average guy to test for this problem though connecting the sensor to an older A-01 Rcexl, CH or RCXP ignition will show it instantly just by watching the spark. A-02 HV ignitions don't show the problem as readily.

Sensors sold by RC Extreme Power and a few other sources don't exhibit this problem.

I agree with others, as long as you are in the 28 degree range, plus or minus a few degrees, you're good to go. Less advance will yield a smooth running engine with just a bit less power. Power will increase with more advance up until a point where the engine will become rough running and harsh. The much published 28 - 30 degrees just seems to be the best all around compromise between smooth running and power.
Truckracer is offline  
Reply With Quote
Old 09-21-2015, 04:41 PM
  #6  
CARS II
Thread Starter
My Feedback: (7)
 
CARS II's Avatar
 
Join Date: Oct 2002
Location: Sacramento CA
Posts: 5,065
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Thank you all for replying but.........

I didn't explained myself to clearly, I think.

On the DLE 35 I get a spark @ 46 degrees when turning the prop counter clockwise facing the engine ( the normal way ) and I get a spark @ 26 degrees when turning the prop clockwise facing the engine and that's why I'm asking if they may have timed the engine turning the prop clockwise because it is closer to the 28 degrees?

I don't get the double spark, what I noticed with the buzzer and the spark plug is that the buzz and the spark happens right when the magnet starts passing under the sensor when turning the prop counter clockwise and clockwise.

With the BME 61 that has a CH ignition the spark happens exactly at 28 degrees counter clockwise and I think that is how it should be.

I concluded after checking both ignitions that the sensor on the CH ignition is precise and the sensor on the DLE is way off or imprecise because the tone been so long when tested.

I hope this helps and if it doesn't I will have to do a video to clarified
CARS II is offline  
Reply With Quote
Old 09-21-2015, 04:51 PM
  #7  
Truckracer
My Feedback: (19)
 
Join Date: Apr 2004
Location: Des Moines, IA
Posts: 4,955
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

If you have a sensor that is triggering a spark just as the magnet starts to go under the sensor, the sensor is defective. 44 - 46 is what you see under these conditions. It just shouldn't work that way under normal conditions. Mount a good sensor in the existing holes and you will see the timing exhibit normal numbers. From there, I don't know how to explain it any simpler than I did in my post above.

Perhaps Adrian or BCCHI will come on here and chime in with some additional info.
Truckracer is offline  
Reply With Quote
Old 09-21-2015, 06:35 PM
  #8  
CARS II
Thread Starter
My Feedback: (7)
 
CARS II's Avatar
 
Join Date: Oct 2002
Location: Sacramento CA
Posts: 5,065
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

I agreed with your assessment and that's exactly what I'm getting, I read somewhere regarding the not so accurate sensors and your comments are confirming that, specially after seen how a good sensor should work, that's why I checked the BME to get an idea of what I should be getting when timing an engine.

I also concluded to get a new sensor from Adrian to fix that, I watched Adrian's video on timing ( who has not ) and I remember him saying that the spark should come after the magnet has passed the sensor.

All in all very informative info, I started this thread to finally clarified the timing on the DLE 35RA once and for all ( to many guys asking and not getting a clear answer )

Thank you, thank you to all, specially to Adrian and Truckracer who are always available to answer all smart and dumb questions coming from me

I may do a video to demonstrate timing of the DLE 35RA and the defective sensor compared to a good one.

Last edited by CARS II; 09-25-2015 at 08:44 AM.
CARS II is offline  
Reply With Quote
Old 09-22-2015, 07:24 PM
  #9  
CH Ignitions
My Feedback: (11)
 
Join Date: Aug 2009
Location: West Palm Beach, FL
Posts: 394
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Hello everyone,

Truckracer is absolutely correct on his post.
Guys as far as I know... in this RC world currently are 2 engines that come factory 40BTDC timed.
OS FG 40 that is timed 40BTDC and that is when LED/Buzzer FIRST COME ON, ( not when comes off like 95% ot the engines)
NGH 38 but that was factory wrong set 40BTDC and using regular 30 BTDC CDI.
I am not sure and do not hold me responsible but I think that all engines after August 2015 may come
with the new cdi that will be 40BTDC when sensor leaves the magnet.
3W uses something similar on the new 4 wire sensor CDI...but they are a bit different, and I have a direct OEM replacement for those also.
I am sending Carlos one of my Allegro sensors I use to see if that cures the issue.
Sensor could be defective as trucker mentioned, but also I seen when magnet was not all the way in and sensor was getting triggered by the cylinder edge.
The CDI I do not see a reason to be bad , it triggers when sensor sends the signal.
One thing tho I will suggest is to disconnect the sensor, power the CDI direct to a fully charged battery and then put a jumper/paper clip between Black and White wire.
Look to see when you get the spark.
You should get a spark every time when you release.( like the sensor will go off the magnet) if you get when you touch, then CDI have a bubu...LOL
While I am at it...I seen on other posts when people were saying that once passes the magnet the CDI auto-trigger. Here is an easy fix, between the red and white add an 10K 1/8 w resistor.
Some times the circuit gets sensitive, the length of the wire that is like an antenna and picks up stray signals and makes the CDI to fire continually.
It will be OK if you use one of the signal generators that CH used to make or Rcxel, but once you add the sensor wire to the cdi it can do that.
Also if you use a 110v power supply to 4.8-8.4v this also can do it, the power line may interfere with the CDI.
What else...? Any other questions contact me by email chignitions@gmail.com or my cell 561-927-6171

I will also add a link on a video that I made last year regarding engine timing.


https://www.youtube.com/watch?v=DTwyptJpJL0 Carlos, Please send me the link from the other forum.
Thanks
Adrian

Last edited by CH Ignitions; 09-22-2015 at 07:29 PM.
CH Ignitions is offline  
Reply With Quote
Old 09-23-2015, 05:05 AM
  #10  
CARS II
Thread Starter
My Feedback: (7)
 
CARS II's Avatar
 
Join Date: Oct 2002
Location: Sacramento CA
Posts: 5,065
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Adrian, thank you for participating, this is the thread I was talking about

I will be making a short video where I will show the timing of the DLE 35RA ( fallowing Adrian's instruction on how to do it ) and more specific how it is happening and where is the magnet when it happens.

I will be using the HK Gas engine CDI ignition test and timing tool, Adrian's timing wheel ( printed from his website ) also I will be doing the timing with the spark plug.

Send you a PM Adrian.

Last edited by CARS II; 09-25-2015 at 08:45 AM.
CARS II is offline  
Reply With Quote
Old 09-23-2015, 10:19 AM
  #11  
w8ye
My Feedback: (16)
 
w8ye's Avatar
 
Join Date: Dec 2001
Location: Shelby, OH
Posts: 37,565
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

I consider this thread to be extremely important for two reasons . . . .

First is all the confusion caused by Tower Hobbies DLE Manuals listing the ignition timing by them turning the prop the wrong way . .

Second is the "shadow effect" of some RCEXL sensors and how to identify and recognize the problem . . .

I consider some of the contributors to be the absolute "Experts".

Adrian explains some exceptions to the traditional 28 degrees before top dead center timing setting due to additional timing adjustments in the ignition module of some ignitions.

Enjoy

Last edited by w8ye; 09-23-2015 at 10:56 AM.
w8ye is offline  
Reply With Quote
Old 09-23-2015, 10:47 AM
  #12  
Truckracer
My Feedback: (19)
 
Join Date: Apr 2004
Location: Des Moines, IA
Posts: 4,955
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

It should be mentioned that the sensor sold by RC Extreme Power exhibits none of the problems associated with many of the RCexl sensors. Further, it is adjustable in two directions so a "sweet spot" above the magnet is easy to find. By sweet spot, I mean the size of the area above the magnet where the sensor will trigger. This area is much larger on the RCXP sensor than it is one the RCexl one. If an RCexl sensor exhibits problems, I have found no way to resolve that problem other than replacement. No adjustment or spacing will resolve the problem.

I'm sorry to say I have not tried the CH sensors for this application so I don't know how they act. There have been zero complaints about them though so I'm assuming they are similar to the RCXP sensors.

While this seems to be a common problem on some DLE engines, it is not limited to DLE. Many other engines that use the very popular RCexl ignition also suffer from this same sensor problem. If your engine has any of the following problems: is hard to start by hand, wants to kick back when starting, has poor acceleration regardless of how you adjust the carb and / or it has a persistent high speed miss, you may have the problem described in this thread.

Guys, we're talking about less than a $10.00 fix here that makes the difference between a great running engine and a door stop.

Last edited by Truckracer; 09-24-2015 at 08:51 AM. Reason: add reference to non DLE engines
Truckracer is offline  
Reply With Quote
Old 09-23-2015, 12:47 PM
  #13  
CARS II
Thread Starter
My Feedback: (7)
 
CARS II's Avatar
 
Join Date: Oct 2002
Location: Sacramento CA
Posts: 5,065
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Agreed, thank you.

The intention of this thread is to clarified and learn ( I know I will )

Since it has been suggested that the RC Extreme power sensor will be a good replacement then I have just ordered one from Milton to also install and demonstrate on a video how well it works.


Thank you for the suggestion T.

Last edited by CARS II; 09-25-2015 at 08:45 AM.
CARS II is offline  
Reply With Quote
Old 09-23-2015, 12:54 PM
  #14  
CARS II
Thread Starter
My Feedback: (7)
 
CARS II's Avatar
 
Join Date: Oct 2002
Location: Sacramento CA
Posts: 5,065
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Thank you to the moderators for making this thread a sticky one

Last edited by CARS II; 09-25-2015 at 08:46 AM.
CARS II is offline  
Reply With Quote
Old 09-23-2015, 01:12 PM
  #15  
w8ye
My Feedback: (16)
 
w8ye's Avatar
 
Join Date: Dec 2001
Location: Shelby, OH
Posts: 37,565
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

+1
w8ye is offline  
Reply With Quote
Old 09-24-2015, 07:00 AM
  #16  
BadAzzMaxx
 
Join Date: Dec 2005
Location: Auburn, GA
Posts: 1,363
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

The problem with the double spark on the RCexl sensors has been going on for over a year, there are a couple of the well known RC engines that have gone with a different ignition company because of the problem.

When I found the problem I started replacing the sensor on the RCexl when I sell and have not had a problem with the ignitions.


The only RCexl ignition I sell are the twin ignitions and got a new order last week and they still have the problem sensors with them.


On the timing, If you can not believe the manufacture who can you believe.



Milton
BadAzzMaxx is offline  
Reply With Quote
Old 09-24-2015, 06:15 PM
  #17  
CARS II
Thread Starter
My Feedback: (7)
 
CARS II's Avatar
 
Join Date: Oct 2002
Location: Sacramento CA
Posts: 5,065
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Milton

Thank you for participating on this thread, your postings are very much appreciated.

Last edited by CARS II; 09-25-2015 at 08:46 AM.
CARS II is offline  
Reply With Quote
Old 09-25-2015, 12:28 AM
  #18  
CARS II
Thread Starter
My Feedback: (7)
 
CARS II's Avatar
 
Join Date: Oct 2002
Location: Sacramento CA
Posts: 5,065
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Here is the video showing the DLE 35 with the Rcxcel sensor.





https://www.youtube.com/watch?v=cIgmhjBiJdQ

Last edited by CARS II; 09-25-2015 at 06:46 AM.
CARS II is offline  
Reply With Quote
Old 09-25-2015, 07:31 AM
  #19  
jwrich
My Feedback: (17)
 
jwrich's Avatar
 
Join Date: Jul 2002
Location: Enid, OK
Posts: 956
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Thank you Carlos for your work with these engines. I still have a problem understanding what is the best setting to run these DLE engines. I have two DLE 35 and one DLE 30 plus a CRCR 26 and RCGF 15. I have always run Zenoah engines, 38s & 26, with the magnito system. I am currently running one 35 with no problems, so I have not mess with it. However, the DLE 30 has never run right, at first I thought it was the carb. So I ordered a new Walbro carb from Valley View RC, still not right. So I will try to check the firing with the degree wheel.

I see you are still flying the Citabria. Mine crashed because of radio failure, total loss.

Thanks again
Rich
jwrich is offline  
Reply With Quote
Old 09-25-2015, 08:35 AM
  #20  
CARS II
Thread Starter
My Feedback: (7)
 
CARS II's Avatar
 
Join Date: Oct 2002
Location: Sacramento CA
Posts: 5,065
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Yes, thank you and you're welcome Rich.

I hope you get answers from this thread to your DLE questions.

Last edited by CARS II; 09-25-2015 at 08:47 AM.
CARS II is offline  
Reply With Quote
Old 09-25-2015, 09:42 AM
  #21  
CARS II
Thread Starter
My Feedback: (7)
 
CARS II's Avatar
 
Join Date: Oct 2002
Location: Sacramento CA
Posts: 5,065
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

I go two emails confirming that the two sensors are on the way, I think I will be getting the firs one tomorrow then I will do a video to show how it works when installed.
CARS II is offline  
Reply With Quote
Old 09-25-2015, 09:54 AM
  #22  
w8ye
My Feedback: (16)
 
w8ye's Avatar
 
Join Date: Dec 2001
Location: Shelby, OH
Posts: 37,565
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

This thread is watched a little more closely because it is a STICKY right now.

Any OFF-TOPIC posts not related to the current RCEXL sensor problem may be moved or deleted?

Enjoy

Last edited by w8ye; 09-25-2015 at 10:57 AM.
w8ye is offline  
Reply With Quote
Old 09-25-2015, 10:35 AM
  #23  
Truckracer
My Feedback: (19)
 
Join Date: Apr 2004
Location: Des Moines, IA
Posts: 4,955
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Originally Posted by w8ye View Post
This thread is watched a little more closely because it is a STICKY right now.

Any OFF-TOPIC posts not related to the current DLE sensor problem may be moved or deleted?

Enjoy
More accurately, it should really be called the Rcexl sensor problem as this problem isn't limited to DLE engines.
Truckracer is offline  
Reply With Quote
Old 09-25-2015, 10:58 AM
  #24  
w8ye
My Feedback: (16)
 
w8ye's Avatar
 
Join Date: Dec 2001
Location: Shelby, OH
Posts: 37,565
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Corrected
w8ye is offline  
Reply With Quote
Old 09-25-2015, 03:02 PM
  #25  
BadAzzMaxx
 
Join Date: Dec 2005
Location: Auburn, GA
Posts: 1,363
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Timing is set at 28-30 degrees before top dead center, checking as the magnet passes the magnet, If it fires as the magnet goes under the sensor that is one of the sensors causing a problem.

Makes no difference what name is on the ignition, If you look on the ignition box it will say RCexl on it somewhere.


I have about 150 of them that I changed out before I shipped ignitions.

I think RCexl knows about the problem but seems not to concerned about it.


As I posted above I just got a new order and they still have the problem sensors.

Milton
BadAzzMaxx is offline  
Reply With Quote

Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service