As I said before, there are two independent ignitions system. Swap components until you find the problem. Start with the ignition modules because they are very easy to swap over. If the problem persists with the vertical cylinder swap the coils. If the problem now moves to the horizontal cylinder then the coil is faulty. If it doesn't it must be the pick up.
Thank you, Chris & laava. Your thoughts are indeed logical. I will direct my attention to the ignition pickups. Admittedly, I have experienced few electrical issues with my bikes over the years. Couple that inexperience with the fact that diagnosing these issues has been my "Achilles heel" in the realm of mechanics, I appreciate all of your help. The saga continues.....
Derek: Your recommendation is very logical. My only reservation in following that procedure is that by limping home on one cylinder & am a tad concerned about putting undue strain on the engine (especially since I live several miles up a long hill. I might be inclined to consider taking a chance & replacing ignition modules with new ones if the cost is not prohibitive.
Hi Kit You could try testing the pick-ups before removing them - you can act on the two wires at the connection with the exciter units, the two that run to the crankcase. They should be around 110 Ohms new but could drop to 95 and still work. Comparing horizontal unit with vertical might reveal a problem if vastly different readings but unfortunately (as you found) you might find a faulty unit holds up until hot so this is the best time to try and test them.
Chris: I suspect that heat is the issue here since the sudden shutdown of the rear cylinder seems to only occur when the engine is hot & under a load. I will get this sorted out. I never backed away from a good challenge. Kit
OK, today I followed Chris' suggestion & checked the resistance on the 2 wires coming from each ignition pickup. Readings were as follows: front cylinder - 105 ohms (within spec) & rear cylinder - 7,000 ohms (no, that is not a typo!). However, I noticed that one of the wires to the corresponding exciter unit was severely crimped entering the 2-wire plastic connector. After cutting off that section of wire, I rechecked the resistance. This time it was 135 ohms (a tad out of spec but a far cry from 7,000 ohms). Maybe, just maybe, that would explain the sudden loss of spark in the rear cylinder. Fortunately, the Ducati has replacement connectors available. I should receive them in about a week. I will keep you posted.
Well, it's time for an update (I have been out of town for awhile). I repaired the crimped wire (as noted above). Also, I reversed the wires from the ignition pickups to the exciters. My logic was as follows: If the bike now ran perfectly, then the problem was indeed the crimped wire. Problem solved. However, if the ignition pickup was the problem, then the front cylinder should not fire. After running the bike for an hour & a half, the rear cylinder again stopped firing. To me, that suggests that the ignition pickups are not the problem. The next logical step is to switch the ignition coils. If the front cylinder stops firing, that suggests that the rear coil was the culprit. Does all this make sense?? As mentioned before, this is new territory for me. Thank you for your help. Kit
no Kit, it doesn't make sense - the cylinder that is breaking down is still the rear one, and always has been, is that correct? It can still be the rear cylinder pick-up and you can't rule it out by other tests unless you manage to get the rear cylinder to fire reliably again.
You are correct. The rear cylinder has always been the one that breaks down. However, when I switched the 2 wires from the pickups to the exciters, I assumed that the pickup that fired the rear cylinder would now fire the front cylinder. So if that pickup was the culprit, then the front cylinder should now break down. Please straighten me out here.
