999 Misfire On One Cylinder Below 3000rpm. Advice Appreciated!

Discussion in '749 / 999' started by Dorset Desmo, Apr 17, 2016.

  1. Just found & read through Bluey's thread "Misfire AT Low Revs" as my 999 has seems to have developed a misfire (one cylinder cutting in and out) under 3000 RPM.

    Bike runs fine above 3000RPM but stalls with throttle off approaching junctions, roundabouts etc.

    200miles ago had a Cam Belt, Valve Clearance service with new spark plugs, TPS reset etc, but has been misfiring since and seems to have got worse the last time I rode it (about 100 mile ride).

    Battery voltage ok & charging ok when running.

    I will have a look at the loom connections, earths etc for anything obvious this week (and swap the DP mapped ECU back to the standard one to eliminate that too) but does anyone have any other ideas / suggestions?

    Cheers,
    DD
     
    #1 Dorset Desmo, Apr 17, 2016
  2. 200 miles?
    Sounds like it needs to go back...
     
    #2 Old rider, Apr 17, 2016
    • Agree Agree x 1
  3. I would start with the front coil.
     
    #3 its me, Apr 17, 2016
    • Agree Agree x 1
  4. I would take it back to the garage and ask them to have a look.
     
    #4 Stonesie, Apr 17, 2016
    • Agree Agree x 1
  5. Thanks for replies - will phone garage tomorrow and see what they say. The mechanic did ride it after the service and said it is nice to ride and pulls well from 2000RPM !

    I was wondering if someone had a previous similar issue and what fixed theirs.

    Hopefully its nothing too serious!
     
    #5 Dorset Desmo, Apr 17, 2016
  6. I have all but eliminated this by setting CO. Well what I actually did was have two exhaust bungs welded on and I fitted two AFR meters with lambda probes and set afr to 14.
     
    #6 bluey, Apr 18, 2016
  7. I changed the front coil and no probs after that.
     
    #7 its me, Apr 18, 2016
    • Like Like x 2
  8. Thanks guys. I have it booked back in for Wednesday - will post findings...
    Cheers,
    DD
     
    #8 Dorset Desmo, Apr 18, 2016
    • Like Like x 1
  9. Which cylinder?
     
    #9 Freak, Apr 18, 2016
  10. Fixed !

    After lots of tinkering, investigation and lots of parts swapping & testing it was one of the new spark plugs, changed when the belts were done, which was faulty.
    New plug and away we go...

    "its me" was the closest I feel.

    Cheers,
    DD
     
    #10 Dorset Desmo, Apr 20, 2016
    • Like Like x 4
  11. Good grief. Who'd have thought it was a faulty new spark plug - what make?
     
    #11 Old rider, Apr 21, 2016
    • Agree Agree x 1
  12. I am pretty sure the plug was a "Chumpion"... Ducati part number 67090161B.
     
    #12 Dorset Desmo, Apr 23, 2016
  13. It can happen if it has been dropped, could have happened anywhere between the factory and the workbench.
     
    #13 Stonesie, Apr 23, 2016
  14. The mechanic took it for a spin after the service and it was fine.
    I took it there in my van so it would be cold for the valve clearances so didn't ride it until a day or so afterwards. It started to misfire below 3000rpm straight away.
    All sorted now but when I rode it back there to get it sorted I could have thrown it in the hedge and walked away due to the ridiculous amount of traffic causing constant revving and clutching due to the misfiring.
    Like it again now though.
     
    #14 Dorset Desmo, Apr 23, 2016
    • Like Like x 1
  15. Yes, Champion are oem and pretty much necessary for dealers to fit. Ngk at least can't be reached properly by the oem plug spanner to be removed, due to the taper in the plug well.
    Not sure about Denso.

    Not sure exactly why but Champion don't seem to have a great reputation
     
    #15 Old rider, Apr 23, 2016
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