This is my first post after recently joining the club.
I’m trying to get my Ducati 500 Desmo Sport going again and wanted to know some basic checks I can conduct on the electrical system. I have a multi-meter.
The key question I wondered if anyone knew my confirm whether my woes are with a faulty ignition coil.
The bike is electric start only and turns over well and freely but doesn’t get a spark. All lights, indicators, horn function perfectly. Upon checking the ignition coil I get a reading of 12.7V when the ignition is turned on at the key. It drops to 10.4V or so when actually turning over on the starter button. However I can’t get a spark? I tried removing / replacing the plug caps. Removing / replacing the HT leads. I even tried a different ignition coil which behaved in the same fashion. If power is going in but not coming out surely this is at fault?
Any advice / help would be much appreciated.
Has the timing been set up correctly ??
Yes the timing is all setup correctly. However we did have to repair one of the electrical pickups - (broken wire). However we did this by connecting a bullet connector and heat shrinking. The connection / seal looks sound now. Is there a way to test this pick-up to be absolutely sure?
Not sure, but if there’s power to the coils it’s strange that there is no spark, hopefully someone wil come along with more knowledge,
Yes that’s what I found confusing. With the ignition on at the key I was getting 12.7V at the input on the coils so I found it odd that there was no spark? There are two inputs on the coils but I could only really check one - maybe I need to do both, however I thought one might be a neutral? The one I was checking was coming down from the switchgear. Hopefully someone will help me get the the bottom of it.
Not sure if you resolved this issue as it was listed in 2019, I’ve only just seen it.
If you have a multi-meter you can test the individual ignition pick-ups, they are small coils of wire that will induce a very small voltage/current when the engine turns over and the ignition stator rotates.
- Switch ignition OFF.
- Disconnect the ignition pick-up leads but ensure you note their wire colours etc for correct reconnection.
- Remove spark plugs.
- Engage 1st gear.
- Set multi meter to DC Voltage and connect across one pair of pick-up wires.
- Slowly rotate engine by turning rear wheel.
- As the ignition stator passes the ignition pick-up you should see a very small increase in the Voltage, maybe only mV. OR you could set the multi meter to Current and you may see a very small increase, maybe only mA, when the stator passes the pick-up.
- Repeat for the other pair of pick up wires, you should obtain the same result but perhaps 180 Degrees engine rotation out from the other pick up.
Hope this helps.
Thank you for your reply. No unfortunately I do still have the issue. The Ducati has been laid up for sometime now because of it. I hope to get back into looking at it shortly with the aim of having it usable again for riding next year. I do have a multi-meter so this information and the explanations will be invaluable, thank you.