Misc: Electrical (General) Tachometer pulse sensor problems

Chris Launders

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Many years ago I had a Krober rev counter on a BSA, this ran off the points via the end cap like the cut out wire, so was using the LT pulse rather than the HT one. Could you couple the meter wire to this instead of the pulse sensor ?
 

Mike 40M

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Had problems fitting a Scitsu on a CB250 racer (180 degree crank). Took some time figuring out best fit of the pickup wire. Direction sensitive. Of course not your problem, but had to have at least 2 inches distance between pickup wire and ignition coil to get steady reading.
 

indian-vincent

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You should try putting a diode between the moto-gadget sensor and your tachometer. The output from the sensor will be minimal so a small one is OK. ( If you don't have much electronics knowledge a diode is basically a one-way valve.) A 1N4001 diode costs literally pence. Do a search on the internet. If it doesn't work try connecting the diode the other way around as it may be blocking in the wrong direction. There were tachometers that looked like the Smiths ones available a few years ago but the one-man band stopped making them. These worked once a diode was fitted in the feed to the tacho.
Tried the diode as well as the shielding of the moto gadget leads, still the same
 

BigEd

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Tried the diode as well as the shielding of the moto gadget leads, still the same
  1. Did you try reversing the diode?
  2. Try connecting up to the BT-H magneto to check if the system is still actually working. Spinning the BT-H magneto with your fingers should be enough to see if the Tachometer flicks to indicate that something is happening.
 

vibrac

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Lots of after fit rev counters just work on a wire wound a few turns around the HT lead ie without a moto gadget (i have one that works like that in front of me) worth a try....
 

vibrac

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its part of a acewell 65 series of combined instruments either wrap the sensor wire 3 or 4 turns round the HT lead or plug it in to the non ground connection twixt coil and CDI (I prefer coil round HT) especially as the rev counter on the Racer works that way as do skitsu rev counters
 
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