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Re: Starting problem
Posted: Thu Jun 09, 2011 12:33 pm
by romus
paso750 wrote:In turn that means the spark isn't timing with the turn over, correct?
No, there´s no way the spark timing can vary. The pick ups get their signal from the flywheel which is mounted on the crankshaft which is turned by the starter. So no matter if the starter turns fast or slow the "firing signal" to the CDI unit will always be right or let´s better say as set by the pick up (bracket) position.
G.
okay, thanks. So when I put the new Digiplex on and got it going it hummed away nicely. It wouldn't do that if there was a coil spark issue would it? So, because of the clunking in the engine case when turning over to start - that's why I am thinking it's the sprag clutch, just not turning it over enough. Something I read says engine can clunk if backfire of starter motor. I'm trying to read to figure out what causes what.
The only thing I haven't done electrical wise is measure the output of the pick-ups, as you said (check pick-up/flywheel clearance and pick up bracket marks - if nothing was done to these parts this is not necessary). But, since I had not ever done anything to these parts, I have presumed not necessary to check. And before my start problems the battery was not running down.
Re: Starting problem
Posted: Thu Jun 09, 2011 12:50 pm
by higgy
No, there´s no way the spark timing can vary. The pick ups get their signal from the flywheel which is mounted on the crankshaft which is turned by the starter. So no matter if the starter turns fast or slow the "firing signal" to the CDI unit will always be right or let´s better say as set by the pick up (bracket) position.
Not entirely true...In the digiplex of this vintage if the secondary resistance is off one way or the other internal timing signals can be out of sync causing a misfire. It is the nature of CDI, resistance is everything.
It is also the reasoning behind the preference for champion plugs for which the unit was designed
which are of course not to be found anywhere anymore
Re: Starting problem
Posted: Thu Jun 09, 2011 1:05 pm
by paso750
ok, if that is so. I did not consider the Digiplex.
From the mechanical point of view it`s impossible.
What secondary resistance are you referring to btw and how is it a problem getting Champions ?
Maybe in the shop around the corner but just check internet shops or ebay.
Re: Starting problem
Posted: Thu Jun 09, 2011 1:43 pm
by higgy
The champion of old is different from what's out there now. Don't know what the difference is that prompted the new classification. I'm all ears tho
Re: Starting problem
Posted: Thu Jun 09, 2011 2:24 pm
by paso750
what do you mean by classfication, the renaming from YC to HC ?
R = radio interference suppressed
A = 12mm thread, 19mm thread length, 18mm wrench size (some tables say 16mm)
8 = thermal value
H = isolator projection 0,75mm (Y = isolator projection 1,5mm)
C = copper core electrode
I guess isolator projection means how long the electrode sticks out the isolator.
Re: Starting problem
Posted: Thu Jun 09, 2011 2:49 pm
by higgy
was that the only change g ? I Have not bothered to look into in depth
Re: Starting problem
Posted: Thu Jun 09, 2011 2:55 pm
by paso750
got that from a german CHAMPION overview.
Here`s an english one
Re: Starting problem
Posted: Thu Jun 09, 2011 4:17 pm
by higgy
Re: Starting problem
Posted: Thu Jun 09, 2011 5:01 pm
by paso750
while the 906 workshop manual says YC the user manual already says HC so Ducati knew of this change and edited the manuals accordingly.
Re: Starting problem
Posted: Thu Jun 09, 2011 5:17 pm
by higgy
Re: Starting problem
Posted: Wed Sep 07, 2011 9:40 pm
by romus
Phew...Yihaa...finally got it going.
The last job was to replace the sprag clutch. There was some clunking that had developed during my starting efforts - probably was there before, but I didn't notice.
So, I put in a KTM part 58440026000, which is cheaper and equivalent to the Ducati part 70140011A. Bike started up like a beauty and is regularly starting no problems.
Seems I had multiple issues because from my work in an attempt to get it started I found some wire connections badly in need of repair, a Selonoid that seemed to need replacing and I got a replacement CPU after they tested it and said it was shot.
Okay, that took me a long time, but I sure moved up in my learning curve understanding on the electrics and starting components :-). Basically my electric side has had a thorough overhall.
P.S. Sprag clutch KTM part 58440026000 can be got for 66.45 pounds, which includes freight from
http://www.speedaway.co.uk. On their site it is under FREE-WHEEL FWD 332008 BLS (58440026000). That was the cheapest I could find to Australia. You will read on-line that it goes on backwards for the Ducati. That's easy to see - one side has a left directional arrow the same as the Ducati one (facing you as you look at it when it is in). So, that side is put in the same as the one you take out. There is a KTM circlip you take off the back and I used the original Ducati circlip (thicker) to put it back in.
I used a heat gun to get that crank shaft bolt off and when putting it back together - Loctite 648 and a replacement alternator gasket.
Some ueful links were:
http://www.mad-ducati.com/ShowPage2.php ... lutch.html
http://www.perthstreetbikes.com/forum/f ... tch-85481/
http://www.mad-ducati.com/ShowPage2.php ... over2.html
http://www.apriliaforum.com/forums/show ... p?t=155882
http://faq.f650.com/FAQs/SpragClutchFAQ.htm
http://forums.ducatipaso.org/viewtopic.php?f=1&t=705
Re: Starting problem
Posted: Thu Sep 08, 2011 2:11 am
by Mc tool
Where do I get these "indexing shims" from , nobody round here has heard of them , they all thought I was mad
Re: Starting problem
Posted: Thu Sep 08, 2011 3:03 am
by higgy
go karts use them all the time or you can order them directly from champion
Moroso also carries them and Accell
Re: Starting problem
Posted: Fri Sep 09, 2011 8:54 am
by Mc tool