Missing reed switch
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wrote on 19 Oct 2023, 21:41 last edited by
Hey all! My first post here. I have a 2002 DT 125 R with a full power front pipe, but she currently won’t go past 60. I’ve looked over the various forums and pages and I know there should be a reed switch, however rather than removing it from the speedo, some special case has cut it off and wrapped the wires up separately.
Any ideas of the issues this may/ are causing? I’d expect more than 60mph to be honest. I do also need to check the powervalve, but want to know the implications of the missing switch. All I see everywhere is DO NOT REMOVE IT UNDER ANY CIRCUMSTANCES… but not what removing it actually does ha ha
Cheers Will
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Hey all! My first post here. I have a 2002 DT 125 R with a full power front pipe, but she currently won’t go past 60. I’ve looked over the various forums and pages and I know there should be a reed switch, however rather than removing it from the speedo, some special case has cut it off and wrapped the wires up separately.
Any ideas of the issues this may/ are causing? I’d expect more than 60mph to be honest. I do also need to check the powervalve, but want to know the implications of the missing switch. All I see everywhere is DO NOT REMOVE IT UNDER ANY CIRCUMSTANCES… but not what removing it actually does ha ha
Cheers Will
wrote on 20 Oct 2023, 04:29 last edited byI always wondered what simply disconnecting the speedo cable would do.
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wrote on 20 Oct 2023, 08:18 last edited by
It's probably a NC circuit which would be why they say don't remove it.
Just get yourself a Zeeltronic ignition system and be done with it.
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Hey all! My first post here. I have a 2002 DT 125 R with a full power front pipe, but she currently won’t go past 60. I’ve looked over the various forums and pages and I know there should be a reed switch, however rather than removing it from the speedo, some special case has cut it off and wrapped the wires up separately.
Any ideas of the issues this may/ are causing? I’d expect more than 60mph to be honest. I do also need to check the powervalve, but want to know the implications of the missing switch. All I see everywhere is DO NOT REMOVE IT UNDER ANY CIRCUMSTANCES… but not what removing it actually does ha ha
Cheers Will
wrote on 21 Oct 2023, 14:35 last edited by SpookDogI think you’re going to have to get another read switch and put it back to standard, then take it from there.
The last person with similar problems was:
@Mr-Shadi
Had problems with his switch. Do a search for his post on the subject… -
wrote on 23 Oct 2023, 03:24 last edited by
Just pull it out of the bottom of the speedometer housing and wrap it generously in electric tape. Worked on my 2003 DE03.
As I understand, it is a simple magnetic thing detecting the speed needle passing over it. Removed from its position, it detects nothing. I assume that if you cut it, it detects continuously instead.
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wrote on 24 Oct 2023, 22:59 last edited by
Thanks all- any ideas where I could get a new switch?
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wrote on 26 Oct 2023, 06:42 last edited by
I am not an electronics guy, but if I found myself without one I would begin by short-circuiting its cables.
From the looks of it, it's a proximity sensor with two metal blades. In a magnetic field, one is either drawn to or from the other, closing or opening the circuit.
If the ignition cuts in its absence, I would assume that it is supposed to be Normally Closed and that the lack of it leaves the circuit open - which is interpreted by the ignition as the speedometer needle is close to the sensor. Hence, short-circuiting it would keep it closed at all times.
But then again - if it would continuously signal "needle at 80 km/h, cut ignition!" regardless of rpm then the engine would not run at all, would it?
And that was the entirety of my knowledge and understanding of the issue.
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I am not an electronics guy, but if I found myself without one I would begin by short-circuiting its cables.
From the looks of it, it's a proximity sensor with two metal blades. In a magnetic field, one is either drawn to or from the other, closing or opening the circuit.
If the ignition cuts in its absence, I would assume that it is supposed to be Normally Closed and that the lack of it leaves the circuit open - which is interpreted by the ignition as the speedometer needle is close to the sensor. Hence, short-circuiting it would keep it closed at all times.
But then again - if it would continuously signal "needle at 80 km/h, cut ignition!" regardless of rpm then the engine would not run at all, would it?
And that was the entirety of my knowledge and understanding of the issue.
wrote on 26 Oct 2023, 18:11 last edited byIt’s a bit of a headfux isn’t it? The read switch might not be a simple magnetic on/off by the looks of it. It might set to a default mode if it the CDI doesn’t detect a continuity in the curcuit?
@Blasterguy
It would be helpful to know if it only restricts the revs in top gear, or every gear? I would try joining the wires at least once to see if there’s a change at all…It might be easier to get an earlier CDI than a read switch…