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Old 09-22-2015, 07:24 PM
CH Ignitions
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Join Date: Aug 2009
Location: West Palm Beach, FL
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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.

Last edited by CH Ignitions; 09-22-2015 at 07:29 PM.