Missing reed switch
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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
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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
I always wondered what simply disconnecting the speedo cable would do.
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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
I 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… -
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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Thanks all- any ideas where I could get a new switch?
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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.
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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.
It’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…
