No spark...Help?

So....

My 74 Norton 850 was getting hard to start. I ran a thread on it and some great suggestions from forum members directed me to what I found out why it dose not start. No spark. It has the uber reliable tri-spark ignition, CNW single coil conversion and a well charged battery.
I ran some continuity tests on the wires and they all check out ok. I checked the high tension leads and even swapped them for some that I had on another working bike and still no spark. The coils are getting power of at least 12.2-12.8 volts when the key switch is on and the tri-spark red light illuminates on/off as the crank rotates
so no issues there. Is this as simple as the coils going bad and failing? *It was getting harder and harder to start as of late and I actually got a faint spark a couple times with the plugs out of the cylinders and exposed but no more spark, faint or otherwise. *The single CNW coil is about 4 years old at best.

If there is any other suggestions, let me know now? (*I did sell my old OEM coils so I don't have a backup to test with...grrr.)

Hi Sky.
It looks like you have an early version Trispark.
The later version has a push-button spark testing feature.
If you are sure you have isolated the cause, I suggest you contact Trispark at http://www.trispark.com.au/contact/ and discuss your problem with Stephen Kelly.
Ta.

My biggest no-spark problem turned out to be a corroded kill switch. Just a hint FYI.
Jaydee

I don't know about tri-spark ignitions, but boyer ignitions require either a resistance plug OR resistance wires, but not both. I've made the mistake of putting resistor plugs in the bike with resistor wires and the spark was so weak that the plugs were covered in soot pretty quickly... which I thought was a rich condition rather than weak spark. I chased down a lot of other things until I realized my blunder. (I don't know if tri-spark is similar to boyer ignitions, so my comment is just a guess)

Edited to add,..... I have a microdigital ignition ... thanks LAB for pointing out my error.

o0norton0o said:

I don't know about tri-spark ignitions, but boyer ignitions require either a resistance plug OR resistance wires, but not both.

Click to expand...

Boyer analog/ue (Micro MkIII and MkIV) systems do not need cap/plug/wire resistance, only Boyer digital (Micro-Power and Micro-Digital) ignitions.

http://www.boyerbransden.com/faq.html

Why Do I Need To Use Suppressed Plug Caps?
MKIII and MKIV do not require suppressed plug caps for operation although we recommend using supressed 5000 ohm plug caps. Micro Digital and Micro Power units must be fitted with supressed plug caps. Plug caps fitted with suppression resistors are usually fitted to prevent radio interference. Radio interference (noise) can cause more complex electronic circuits like radios and computers to malfunction.

What HT leads do i need to use with Boyer Bransden ignition system?
For all our motorcycle ignition systems, copper wire leads with 5000 Ohm suppressed plug cap is our preferred method, although the MK4 systems can be used without any suppression on the H.T. leads if required.

Click to expand...

Solid state electronics normally fail altogether rather than deteriorate over time. Check that the earth wire for the spark module is 'well connected to earth. If this doesn't show up anything then try running a feed wire direct from the battery to the feed side of the spark module, this will elliminate the possibility of bad wiring, a bad ignition switch or, as Jaydee suggests a corroded kill switch.

Recently had this prob. Clean up the ground(s) ? :!:

Your measured batter voltage is low, especially if you've had the battery on a charge, you should be measuring 12.7/12.8.

Assuming that your battery has been in use and will come back to 12.7/12.8, I think Jaydee may be on to something. Make a jumper from the battery directly to the coil terminal that the Tri-Spark get its power from, do insure that you can easily break this connection in the event of any type of anomaly (engine begins to run away, a short develops). If the Tri-spark is getting full battery power and there are no other appliances drawing power, you either have bad connections or a going south Tri-Spark system unit.

Your coil should measure 3 to 5 ohms primary resistance and you should have 5000 ohm sparkplug caps. If you have been running without the resistor caps (or plugs---NOT both) then you have, probably injured the system unit.

So: Measure primary resistance, if that comes in between 3-5 ohms, try the jumper (with verified connections in the ignition circuit) Essentially build a "stand-alone" ignition system. If that fails get a new electronic ignition. .

From experience, maintaining a high voltage is not a critical requirement for Trispark ignition systems to function.
I recently found my bike will start with 9.3 volts and the engine continued running until voltage reached 8.4 volts and the engine then stopped. I suspect the clamped, latched kill switch relay I designed may have 'unlocked' at this point rather than the ignition shut down (moot point).
Ta.

Boyer Mk1V. New Odyssey settled in at 12.5 V. Dual 6V. coils. Continuity from pick up wires to B.Box. Touching the BW and BY wires together at transistor plate produces good blue-white spark (s), Reconnecting to the pick up plate and kicking over produces no spark (plugs rested on head for testing ). Ideas ? Am thinking now magnetic rotor magnets could be getting weak and not picking up info reliably as cut outs and sputterings increased over the last month until limpings home. Will order in new magnet plate unless someone says no. 27000 Kms. :?: