Shock treatment

[elliottles1]

folks,

i have a tzr 125 with powervalve.
from the cdi to power valve controller there is a wire that sends the rev. signal so as the controller knows when to start opening the power valve. the bike starts and runs perfectly and i am very pleased with it. however i am wiring a digital rev counter and following instructions to take the signal from the said wire.

upon disconnecting the said wire with the bike running i got a shock equally as strong as holding the ht lead to the plug.

there is no short/connection from the ht lead to the frame etc. the bike runs perfectly.

does anyone know why this should be, i do not want it to be a fault that will burn out a rather expensive power valve control box.

cheers
les.

[rodneya]

There is 12 volts in the powervalve controller wire. The powervalve feed wire on my Dyna CDI is 12v 500ma. I dont have powervalves om my current setup, so it is taped off so that it doesn't short.
There is a separate 12v pulsed wire for tach feed that I use though.

[1976RD400C]

I think said wire is connected to the primary side of the coil and the cdi is probably sending out fairly high voltage to the primary side OR when the secondary side of the coil windings collapse, to make the spark,  it induces a voltage back in the primary side windings. You can get a nasty shock off a 12 volt points system if you hold your finger on the nut the wires connect to on the points and are grounded with it running. The rev counter is just looking for a on/off signal and doesn't care about the voltage.  I hate shocks.

[elliottles1]

than;ks for that guys, i feel a bit better now. wont be licking it any time soon tho.

les.