97 M900 - NOT STARTING

[greenohawk69]

Tried starting the bike and it sounds like it is close to starting, but won't turn over. Even tried going downhill and stsrting in second gear, but was not successful.

* carbs were removed and cleaned
* new fuel lines installed
* manual petock - flow is good
* tank had been removed and compressed air blown through orifices
* new heavy duty battery cables - negative attached to engine; engine sanded and cleaned prior to attaching cable
* open airbox
* almost new spark plugs
* replaced ignition coils (CA Cycleworks exact fit coils)
* battery is less than two years old and charge it at least weekly
* use a second battery to see if there was a problem with the first, but same symptoms

Bike was previously running, but suddenly quit when I was on a tuning run. Heard a pop - fuse blew for LED headlight / tailight.

Had to fix multiple bare wires before headlight would work again.

Fuel doesn't appear to be a problem as I can smell it and also see it when twisting the throttle.

Any suggestions as I'm sure I'm missing something.

[Howie]

How well is it cranking over?  Got spark?  Coils hooked up correctly?

[greenohawk69]

How well is it cranking over?  Got spark?  Coils hooked up correctly?

From my perspective, it's close, like 90-95% there. I didn't check spark. How do I go about checking it? I would say yes as they've been nstalled for a few years and the bike ran fine.

[ducpainter]

Check for spark by removing the plugs, and grounding them and cranking the motor. You can do one at a time. It should be blue.

Did you check all the other fuses?

Check wiring to the kill switch...since you messed with wiring near the headlight?

[greenohawk69]

Check for spark by removing the plugs, and grounding them and cranking the motor. You can do one at a time. It should be blue.

Did you check all the other fuses?

Check wiring to the kill switch...since you messed with wiring near the headlight?

Grounded against the motor - no spark of any kind/color on either plug.

Is this an ignition coil issue? Something else?

Checked and re-checked fuses, all ok.

Would the kill switch be an issue if when pressing the start button, it attempts to start? Clutch moves, starter relay clicks and air moves out of the spark plug holes.

[ducpainter]

Carburated Duc's kill the ignition.

Fuelie's kill the fuel.

Check the wiring from the kill switch. If it isn't external, it can be in the harness near where it passes the steering head.

[greenohawk69]

Wiring appears to ok. Cut open the rubber around the wiring and did not see any broken wires. Tightened up a screw on the bottom of 1 ignition coil, but bike still not starting.

Back to the grounding of the spark plug against the engine. I pressed the plug's metal part in the middle against the engine - is that effective? As it appears it is painted/coated (OEM).

[ducpainter]

It usually is effective unless the engine has really thick paint/powder coating. You could use a jumper wire if you're unsure.

[greenohawk69]

I sanded down one of the fins to bare metal, but still no spark.

Also swapped ignition coils back to OEM, but get same turning over and no start.

When I am inspecting the starter switch and corresponding wires - I have checked the condition and if they're properly connected. Nothing seemed to be out of the ordinary. Fuses are good.

Are there tests I can do?

[ducpainter]

OK...no spark.

Trace the wires from the kill switch and jump them at the harness end.

Still no spark?

Not likely the switch.

[Howie]

Lots of stuff to check, in no particular order:
   Ignition switch
   Kill switch
   Fuses (check them with a meter)
   Ignition modules (unlikely both are bad unless you did something to kill them)
   Coils (OK, you did that)
   Ignition pick ups (unlikely both are bad, but easy to check.  Unplug the two wire connection at each module.  95-105 ohms each. 
   All wiring between the components including the high tension leads.  The caps should read about 5K ohms.
   And yes, I might have missed something.

You do want a manual and wiring diagram if you don't have one.  https://haynes.com/en-us/motorcycle-manuals/ducati

Example:
   Find connector between ignition switch and main harness. 
   Disconnect
   On the switch side you should have continuity between terminals 3 and 6.

Another alternative is get the bike over to a good shop.  It took me the majority of my life to learn that option.

[ducpainter]

If you need a wiring diagram let me know.

[greenohawk69]

Lots of stuff to check, in no particular order:
   Ignition switch
   Kill switch
   Fuses (check them with a meter)
   Ignition modules (unlikely both are bad unless you did something to kill them)
   Coils (OK, you did that)
   Ignition pick ups (unlikely both are bad, but easy to check.  Unplug the two wire connection at each module.  95-105 ohms each.  
   All wiring between the components including the high tension leads.  The caps should read about 5K ohms.
   And yes, I might have missed something.

You do want a manual and wiring diagram if you don't have one.  https://haynes.com/en-us/motorcycle-manuals/ducati

Example:
   Find connector between ignition switch and main harness.  
   Disconnect
   On the switch side you should have continuity between terminals 3 and 6.

Another alternative is get the bike over to a good shop.  It took me the majority of my life to learn that option.

Ignition p/u's > V = 104 ohms, H = 103.4 ohms

Switch, terminals 3 and 6 = continuity. Put red probe to terminal 3 and black probe to terminal 6 = 0.3 @ 20 ohms selector on multimeter

Fuses = 12.85V both sides when power switched on and black probe connected to negative battery post. Battery = 12.85V.

Caps? Said to check, s/b 5K ohms...how do I check? Red probe to one side and black probe to other with power on?
> with selector @ 20 ohms, I got a zero "0" reading. Switch probes to opposite sides and same thing. On bottom of coils.

I have a wiring diagram and manual. Trying to avoid moto shop as they charge $100+/hour and I'm currently under employed. And I am a glutton for punishment and want to learn.

[Howie]

The cap on the end of the spark plug wire that clips onto the spark plug wire.  It has a 5K ohm resistor.  Meter has to be on a scale higher than 5K ohms.  NEVER power on with an ohmmeter.  My next step would be to confirm power is getting to the ignition modules.  Unfortunately I don't remember the wiring on the modules, but the power does come directly from the kill switch.  Also make sure the ground is good at the modules.  One probe on the black wire at the module connector, one probe to negative on the battery.  Close to 0 ohms.  Is it possible to borrow a known good module?  Do be careful!  Under employed and ignition modules do not go well together. 

Am I correct in assuming everything but the ignition (warning lights etc.)  is working?

Maybe Speeddog could come to the red phone?

[Speeddog]

You rang?

Unlikely to have both modules die at once, but it can happen, most times brought on by running with battery terminals loose.

The wiring from the pickups is very light gauge, and I've seen a few of those broken, usually up at the connector to the modules.

The wiring terminals that slide over the spades on the coils can lose tension over time, and can slip off when doing the kind of work that's been done.

All of the above are most likely to only effect one cylinder, but still very much worth checking.

Confirm that the connector that powers the coils is secure and the terminals aren't pushing out when you mate the connectors.
It's the one on the right side of the airbox.