Starting Issue

Discussion in 'Technical Help' started by Paul Cuthbertson, Dec 30, 2017.

  1. yip, random as hell.
     
  2. It's a funny thing. I've only heard of this problem with the starter motor on the Mk1 Multis, yet lots of other Ducatis use the same starter, the same ECU and basically the same electrics. Why is only the Multi affected? Or perhaps others are and I haven't heard.
    I believe that the ECU shuts off if the supply voltage drops below a certain level, something like 10.5V. It could explain why the sparks, and presumably the injection, stop when the starter is turning if it is not 100%.
     
  3. Interesting.
    My SS was pre Exige cable kits and desperately needed one. Even with a new battery, the cranking speed was painful.
    When it did start, it was often as I took my thumb off the button.
     
  4. Love the chat guys, it certainly was confusing that's for sure but, as someone said - once experienced never forgotten, the Ducati lad was also puzzled so he has a new experience under his hat now too. Looking forward to getting out, weather not so good in Aberdeenshire just now but hopefully get a window soon,changed the oil,filter and checked the gauze was pleased to see no bits of piston or anything in the gauze...Paul
     
  5. Roll on Spring :)
     
  6. out of curiosity, could you undercut the old starter commutator to see if it works again? might do as a spare then. The commutator did look a bit worn, so maybe the insuation being harder could be protruding above the softer commutator conductors and needs taking back a smidgin.

    Pete
     
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  7. Weird thing is that it appeared to work fine but there was no spark... :(
     
  8. yes, but could the higher resistance at the commutator, caused by a partial air-gap, produce too much volt drop, and hence current draw in order to get the motor to crank. this could, in theory, reduce the voltage available at injectors or injector pump and therefore cause reduced fuel pressure, and also do similar at the HV circuit (if we assume a transformer circuit then the ratio will be severley affected such that 12V/12kV normal (hypothetical) condition would give a secondary voltage of say 8kv if the primary is dropped to 8V and coupled with a bigger plug gap on the iridium plugs would cause some potential spark issues (doesn't matter about the iridium conductors, the air gap will still have the same resistance which will be determined by distance (and possibly humidity, temperature, etc))).

    just my thoughts, could be a load of old bunkum, though.

    Pete
     
  9. Absolutely.
    Wouldn’t you expect the air-gap, voltage drop and current draw to slow the cranking speed though ?
     
  10. I have the old one safe but not sure what to do with it, thought I could rebush it, but given that my new has 12 months warranty perhaps I will just stick it in a box time being..at least I know there is no issue with it regarding crank speed...
     
  11. I have the old one safe but not sure what to do with it, thought I could rebush it, but given that my new has 12 months warranty perhaps I will just stick it in a box time being..at least I know there is no issue with it regarding crank speed...
     
  12. ?
     
  13. Sorry had we issue with editing:

    Guys last summer I stopped at a cafe in Ballater Aberdeenshire just coming back from Braemar, lovely day and just enjoying the bike run, so stopped for a coffee, Ballater is busy especially late summer, so here I am finished my coffee I was sitting outside, bike was 10 yards away folk were looking at me and the bike then - yes I tried to start it and it just wouldn't start, tried and tried and then when all seemed useless (thinking about phoning for help) she burst into life, I couldn't get away quick enough....
     
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  14. I know the feeling Paul. Many years ago I at was at the IOM TT with the DBD34 Gold Star I had at the time. We had been down to the prom to look at all the bikes and had just returned to our own to set off back to the campsite. Of course as soon as I went to start the Goldie a crowd started to gather. Usually I could start it 1st or second kick but this time, would it feck. After the 4th or 5th kick it was well flooded and I had clear the cylinder and start the whole process all over again. It probably took me a minute or two before I got it started to a great cheer from the crowd but it felt like 10. Like you I couldn't get away quick enough :poop:
    In the summer I'm often up Deeside. I'll keep an eye out for a black Multi :)
     
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  15. Brill - yes please do, I often meet up at the Braemar bike cafe, usually a few guys going about putting the world to right, a friend often meets me, he comes up from Dundee, sadly his son crashed out last summer on his Panigale heading back on the Braemar to Blairgowrie road, he survived but suffered terrible injuries, Gold Star that would of been interesting, not quite the same but I once had a fleetstar 250 never use to start more to do with the piston going up sideways but I have fond memories of that bike, I swapped a bottle of Vodka and an air gun for it...long time ago
     
  16. I think what’s happening here is that the starter is turning at the correct speed giving the impression that it is fine, whereas it actually has a fault, BUT in order to turn at it’s normal speed it draws too much power, the ECU is therefore starved of power (for want of a better phrase) and therefore the ECU doesn’t operate correctly, hence no start.
     
  17. that's exactly what the symptoms were, hence we sent the ECU to Avanti, Antony downloaded all the data and reported back all in order, its all starting to make sense ...will try and get out this weekend weather - not to good though..
     
  18. Paul, as the previous owner of your multi, I am glad you got it sorted.
    Any chance of buying it back now? :rolleyes:
    Seriously, I never knew it had such issues, along with all the other things you've mentioned that it needed.
    Take care. I might see you out and about on the roads.
    Neil.
     
  19. Thanks Neil, no no no regrets its great, yes it was a little tired but that's more down to me wanting it where I was happy although the rear hub bushes and chain and sprockets were goosed, I put 2 new oil seals in the Ohlins too, as one was weeping quite badly I tried the moto cross trick by sliding the seal saver up and it stayed dry for a week or so but inevitably off they came, took the rear carrier off and got it powder coated too as it was corroding, again that's me being fussy, new rear pads as they were just about done too, changed the air filter and plugs and all was good, then the starter motor went, "I think you may have got lucky" as things went down hill mid summer but you know what I am so happy with it now, starts as it should and need to get out (fair weather rider only) as had the alternator casing of plus changed the oil filter too, will feel happy when I know there is no leaks sure there wont be any, oh and just remembered I change the cam cover o ring and the fuel tank seal, no more weeps from them...so its all ready for the better weather, you will have to make me a silly offer for it go now..!!! Yes there cant be many multis going about and great to catch up...
     
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  20. hmm, seeing a common denominator here now, mine originally came from caithness, so its obviously a north east thing. :p
    think i have seen that bike about btw, maybe out Aboyne way with a group of other riders when i have been out and about.
    a wee aside, mine was getting battery voltage at the coils,injectors and fuel pump, it just wast triggering the coils during cranking.
     
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