Riding a thumper with vertical cylinder dead.

[IRISH]

When starting up, only the front would fire until finally the vertical would roar to life. Happened consistently and all was fine after warm up or furl flow or whatever. But, now the vert won't come to life at all.

Any ideas and or how to trouble shoot?

[ducpainter]

What bike?

[IRISH]

99 monster 750,

30k trouble free miles, garage kept

[Howie]

Got spark on the vertical cylinder?

[IRISH]

New plug, no spark, plenty of battery juice, no visual frays or looseness to the coils.

Appreciate your help and want to trouble shoot myself. I need guidance as to tools and what to test.

[chris1044]

How are you checking to verify you have no spark?  Plug inserted into wire and then good wire ground from the electrode to cylinder head?  I'd diag like this:

1) Check for spark with a spark tester
2) Ohm out the wire with a DVOM.  If it's open = replace.  Should be very low on resistance - less than say 10 ohms
3) Ohm out the coil with a DVOM (search...specs for both windings should be out there somewhere) - replace if not in spec
4) Verify the coil is being told to fire per the ECU.  I'd do this with an oscilloscope, but you likely don't have access to one.  In that case if you have a good DVOM you may be able to use that. 
5) Verify resistance from ECU pins to coil connector pins
6) If everything else checks out good..there's a dead driver in the ECU.

You'll need a good schematic or someone to tell you which pins at the ECU connectors feed the coil connector as well.

[Howie]

Check the ignition pick ups for resistance.  The wires exit the right side cover towards the front and go to the ignition modules.  The two wire connector is from the module.  You should have 100+5 ohms resistance.  If both pick ups check good the problem is a module, ignition coil or related wiring.  Firs check all connections are good.  Easiest shade tree diagnostics is to swap parts one at a time from the vertical cylinder to the horizontal cylinder.  The part that causes the horizontal cylinder to not fire is the bad part.  You may or may not have a coil and coil wire that are one piece.

[Howie]

How are you checking to verify you have no spark?  Plug inserted into wire and then good wire ground from the electrode to cylinder head?  I'd diag like this:

1) Check for spark with a spark tester
2) Ohm out the wire with a DVOM.  If it's open = replace.  Should be very low on resistance - less than say 10 ohms
3) Ohm out the coil with a DVOM (search...specs for both windings should be out there somewhere) - replace if not in spec
4) Verify the coil is being told to fire per the ECU.  I'd do this with an oscilloscope, but you likely don't have access to one.  In that case if you have a good DVOM you may be able to use that. 
5) Verify resistance from ECU pins to coil connector pins
6) If everything else checks out good..there's a dead driver in the ECU.

You'll need a good schematic or someone to tell you which pins at the ECU connectors feed the coil connector as well.

The bike in question is carburated.  Spark plug wires have rather high resistance, usually about 750 ohms per foot.  The resistance on a Ducati ignition wire is in the terminal cap to the spark plug, which is 5K ohms + 10%, wire itself should be close to 0 ohms.

Ohm readings on the coils are 4.5 ohms + 15% from small terminal to small terminal and 13.5K ohms + 20% from the spark plug tower (wire without terminal cap if one piece).

[wannabfast]

i like to swap parts if you have 2 availible, swap the horizontal and vertical coils and if the spark moves, replace coil, if not do the other testing

[IRISH]

If we could just speak probabilities for a moment. Would a failing coil have this sort of history, intermittent performance at start up - then work fine after warm up until all out failure?

What are your thoughts?

[ducpainter]

If we could just speak probabilities for a moment. Would a failing coil have this sort of history, intermittent performance at start up - then work fine after warm up until all out failure?

What are your thoughts?

A tired plug could do that too.

However you test by the swap method make sure you only swap one item at a time.

That way you'll know which part is at fault.

[IRISH]

A tired plug could do that too.

However you test by the swap method make sure you only swap one item at a time.

That way you'll know which part is at fault.

Ordered my manual, swapping parts one at a time this weekend. Thanks guys.

[IRISH]

Here's the diagnosis;

After swapping parts and confirming resistance. ohms  with a multimeter, the culprit seems to be the vert cylinder pick up coil.

Anyone have some experience with changing that out....?

[Howie]

You need to remove the right side side cover.  One screw is behind the clutch slave, so that needs to be removed.  You can leave the hydraulic line on, just don't squeeze the clutch lever.  Keep the side cover screws in order, they are different lengths.  A puller, though not necessary, will make removing the cover easier.  A cheap steering wheel puller will be fine.  Remove the alternator cover (small plate on side cover with two screws).  Install puller.  Remove cover.

You will see the ignition pick ups.  If you buy OEM pick ups they come on a bright shiny new bracket.  You can avoid adjusting the air gap  by transferring the pick ups to the old bracket.  Just in case, the air gap is .7 + .1mm.  You would need a non magnetic feeler gauge to adjust the gap.

Reassemble with TriBond or equivalent, or you can buy a gasket from our sponsor  http://www.ca-cycleworks.com.  The torque on the 5mm. screws is 6 Nm, the 6mm. screws 10 Nm.

If you go here  http://www.ducati.com/services/maintenance/index.do  you can download the parts catalog for an '01.  It will be close enough to your bike.

You can buy after market pick ups from these folk   http://www.electrexworld.co.uk/acatalog/Online_Catalogue_Pick_up_Coils_160.html 

[beethoven]

I had same problem couple of yrs ago. I used electrexworld units and replaced both coils while covers off. No problems since. In Oz Electrexworld units less than half price delivered than original.