Bosch ignition input voltage
- Thread starter AndyW
- Start date
Dellortoman
Hero member
- Location
- Tasmania, Australia
I dunno the answer, but I reckon it would depend on engine revs. That feed comes from a little alternator coil that's dedicated to powering the ignition. It works a bit like a magneto. It's un-regulated and un-rectified (so don't forget to switch your meter to an AC Volts scale if you want to measure it).
PS: I have a spare Witt DMC2 if you want to upgrade. It'll work with the Laverda pickups, so is a cheap way to fix a dodgy CDI setup. It's never been used and I don't reckon I ever will use it now that I have Redax alternator/ignition conversions on both my Laverda engines. Make me an offer if you're interested.
PS: I have a spare Witt DMC2 if you want to upgrade. It'll work with the Laverda pickups, so is a cheap way to fix a dodgy CDI setup. It's never been used and I don't reckon I ever will use it now that I have Redax alternator/ignition conversions on both my Laverda engines. Make me an offer if you're interested.
AndyW
Hero member
Hi Cam,
Thanks for that response: I'll let you know if i'm going to go down the DMC route (I have nothing against them). At this point it looks like my actual reason for breaking down in Stanthorpe was a failed ignition though whether it's the box or just a voltage drop out somewhere is anyone's guess.. Kill switch relay seems ok.. I take it there should be no voltage through to the box until the motor cranks over? seems an odd way of doing it. any idea what the lowest and highest voltages through to the box might be?
AndyW
btw your skinny shim arrived today though I've already reassembled and shimmed the motor and lobbed it back into the frame.. just trying to recommission thedamn sweet thing now.. 
Thanks for that response: I'll let you know if i'm going to go down the DMC route (I have nothing against them). At this point it looks like my actual reason for breaking down in Stanthorpe was a failed ignition though whether it's the box or just a voltage drop out somewhere is anyone's guess.. Kill switch relay seems ok.. I take it there should be no voltage through to the box until the motor cranks over? seems an odd way of doing it. any idea what the lowest and highest voltages through to the box might be?
AndyW
btw your skinny shim arrived today though I've already reassembled and shimmed the motor and lobbed it back into the frame.. just trying to recommission the
Andy,
The stock CDI plug caps had no suppression whatsoever, connectors were crimped permanently to the wire with just a simple rubber cap to keep the elements out. What you are measuring is possibly the internally deteriorated 40-year-old plug wire.
piet
The stock CDI plug caps had no suppression whatsoever, connectors were crimped permanently to the wire with just a simple rubber cap to keep the elements out. What you are measuring is possibly the internally deteriorated 40-year-old plug wire.
piet
Dellortoman
Hero member
- Location
- Tasmania, Australia
I don't reckon there would be many original Laverda/Bosch HKZ ignitions still working these days. They were never very robust systems in the first place. Cranking the engine without the plugs connected would fry the box. If yours has died, you can't complain too much - 40 years isn't a bad innings!