No Spark - HELP!

I can't get a spark on my 85 XL600R - I replaced the pulser, CD unit,
coil, sparkplug, and everything else (except the voltage regulator) in
the ingition circuit. What the heck?? I wonder if the ignition on/off
switch could be faulty? What should I look for? I have the sparkplug
out and clipped with big bulldog clips to the frame and there's no spark
when I kick it.

PattiMichelle

 

Disconnect the connector coming from the alternator stator and kick the
engine over as fast as you can while observing the output voltage
across the red and black wires.

I suppose you would need an analog voltmeter to see the voltage jump up
and fall back down. A digital voltmeter might be too slow to respond.

I dunno for sure what it will be, but I would expect at least 50 volts.
That's the supply voltage for the CDI. When the pulser coils fire, the
ignition control unit suddenly hits the ignition coil with voltage, the
coil multiplies the voltage to a higher level (maybe 20KV?) and the
spark plug fires.

You'll probably get around 2 volts across the pulser coils. They send
their signal to the ignition control unit too, telling it when to send
the voltage to the coil.

If you don't get any voltage out of the alternator, maybe the stator is
burned out or maybe it's the wiring connections. An oddball possibility
is that the alternator rotor isn't turning because the bolt holding it
onto the crankshaft has loosened up. I've actually seen this happen.

 

On mine at least, I'd look at the electronic tach. If the ignition
module's
working OK, the tach will show some RPMs when the engine's
cranking. If the tach is dead, this means a problem in the trigger
or control circuit. If the tach registers a few RPMs, then the
problem's
most likely in either the positive feed to the coil or in the high
voltage
side of the ignition.

You did check the kill switch, right ?

 

Are you sure? I thought the primary circuit was connected to +12V
except when the signal from the pulser coil is used to break the
primary circuit causing the electromagnetic field to collapse
inducing a high voltage in the secondary windings. In my (not that
extensive experience) I would expect 12V on the positive coil
terminal (the negative is usually green IME) as soon as the ignition
is turned on. It should be apparent from the wiring diagram.

Jim

 

I am thinking maybe there are a set of ignition modules on the
bike....have you tried replacing those???

Fwed

 

CDI ignitions work opposite from what Kettering type ignitions work.
Honda installed CDI's instead of electronic ignitions on a lot of
motorbikes.

Anywhere from 50 to 500 volts is generated by a separate winding in the
alternator stator. The primary winding of the ignition coil will be a
lot higher than the typical 3.5 to 5.0 ohms found in battery and coil
ignitions. And the XL600R *has* a separate winding, according to
Electrosport's web site. The owner of the motorbike has the option of
using a battery and lights or not.

 

CDI ignitions work opposite from what Kettering type ignitions work.
Honda installed CDI's instead of electronic ignitions on a lot of
motorbikes.

Anywhere from 50 to 500 volts is generated by a separate winding in the
alternator stator. The primary winding of the ignition coil will be a
lot higher than the typical 3.5 to 5.0 ohms found in battery and coil
ignitions. And the XL600R *has* a separate winding, according to
Electrosport's web site. The owner of the motorbike has the option of
using a battery and lights or not.

 

Ah I see. I'd never really appreciated the difference before. The
only problems I've ever had with motorcycle ignitions are fouled
plugs or corroded plug caps (poor contact between resistor etc). If
anyone's interested I found a page giving a good introduction to
ignition systems .

http://www.jetav8r.com/Vision/Ignition/CDI.html

Thanks

Jim