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Discussion Starter #1 (Edited)
Hi all

Following on from my thread about kicking and ignition issues I've managed to get hold of a timing disk and a strobe. So this afternoon I packed a bag with tools and a rag and rode up the hill behind the house - I try not to sit around revving my bike out my front door for my neighbours' sake.

I had my Gopro on my jacket and used that to capture some clips of the results. I trimmed the video down to two clips of the top cylinder and one of the bottom. That video is here https://youtu.be/pGAgC1za6cM

The attached images below are the top twice and the bottom twice, plus a snap f the disk so one can see the marks.

This is what I saw:

With the cable attached to the upper spark lead, the strobe would show the upper case mark to be a degree or more to the left of the line marked V-AA on the disk.

With the cable on the lower lead, it showed the other/lower/left case mark to be close to the line marked V-AA on the disk (not the one marked O-AA)

In both cases, there was no change at all when increasing RPM.

In addition, the lower header had become very blue, whilst the upper had no bluing at all.

So, can anyone here interpret this? I've read that incorrect/reversed wiring (of what exactly?) can cause there to be no advance and that a blue header also indicates this.

  • I'm unsure whether the AA mark is the initial or the advanced mark.
  • I'm also unsure why the test on the lower lead pointed to V-AA and not O-AA.
  • What I am sure about is that the wiring is wrong.

I get the impression that I probably don't need to adjust the pickups and that this will largely resolve with wiring fixes.

Any comments on how to proceed are appreciated.
Regards
Rob
 

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you reverse the wiring for each cylinder at the connector from the pickups. don't mix up o and v though.

as for the marks, i'd pull the plugs and find tdc. that'll give you the best indication.
 

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Hi Rob,

I hate these ignition systems! The front cylinder should show O-AA when full advanced and the rear V-AA, plus when opening the throttle from idle the spark should clearly advance - 6 degrees at 900 RPM, advancing to 16-18 degrees at 1800 RPM, then 28 degrees at 2800, until full advance is reached at 4000 RPM.

I'm surprised that the bike will run at all if the wiring is incorrect, although a previous poster said the reversing the wiring to the pick-ups will stop the advance, so that looks to be your first port of call.

Keep us informed.

Colin
 

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Discussion Starter #4 (Edited)
Thanks for the comments Colin and Brad

So today I was going to simply swap the wires for each pickup and go off to check it all again. However once I had everything apart, I decided to recheck everything I had done when I wired this up a couple of years ago. At the time I posted a thread here where I was very confused about the official circuit diagrams versus what I knew myself and what the pickup maker was telling me.

I've posted a 17 minute video showing what I'm seeing in the manuals and what I eventually did on the bike. It all appears to be correct and the only grey area is the assumption that striped leads on the pickup should go to to striped leads on the bike. I would be reversing that assumption if I go ahead.

https://www.youtube.com/watch?v=1u8kYdJvRQI

The question at the end is simply - Is it really likely that the polarity of the two pickup coils is the problem here? If it is, then I'll change it and put it all together tomorrow and check it. I assumed that the electronics simply detect a change in impedance on the coil and do nothing with any polarity it might have.

As for the confusion about the manuals, I may be completely stupid in my interpretation of the diagrams, but they really don't make sense.
Regards
Rob
 

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Discussion Starter #5
p.s. When I talk about the horizontal cylinder 'firing first' I simply mean the first one after the longer gap. Obviously none actually fires first.
 

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Discussion Starter #6

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Hi Rob,

I've watched the video (very good!) and looked at the links. The workshop manual explains that the view of the pick-ups and the rotor is from the engine side cover, so is inverted, but that does not explain why the horizontal pick-up wiring goes to the vertical cylinder; it could just be a typo, for vertical cylinder read horizontal cylinder.....

It does appear that crossing the pick-up wiring will stop the engine advancing, which would explain the kick-back and rough running and hopefully, the pick-ups are in the correct position for timing. I do know that if the pick-ups are not set with the correct air gap to the rotor then the ignition will not advance properly too, as I've experienced this. The full-advanced setting is not so critical - a very clever guy who used to make high tech ignition systems for racing engines told me once that old four strokes don't mind if the timing is one or two degrees out.

You must be very fed-up by now, but at least you are technically minded, just imagine the problems if you had no knowledge of electrics!

Colin
 

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from memory reversed wires will have it at full advance all the time, not at idle advance. but, regardless, if it's not advancing, swap the wires.

if the pick up gap is too small they will generally idle on the first step, which means as you lower the carb slide stops to lower the idle speed it will lose the first step of advance and then idle very low. but that's about the only issue i've seen with pick up placement.
 

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Discussion Starter #10 (Edited)
Alrighty... results from today.

I pulled the pins from one side of the pickup plug and simply swapped them so that the striped leads would now go to the plain leads. Then I went for a ride and set it up to check the timing again.

Note that the previous test resulted in very strong blueing on the lower pipe, but no blueing at all on the upper. The bike ran but only badly and there was no advance, or it was permanently at full advance, detected on the timing disk.

Here's a video made up of seven or eight clips.
https://www.youtube.com/watch?v=js1WJXlwahw


  • The start and six and a half minutes riding up the hill. It really ran just as badly as it did before. Had to keep the choke on to keep it going.
  • I rode it several minutes longer than shown here.
  • Then I found a spot and set it up for the strobe. I got it on the stand and tweaked the stops to try and get it to idle without having to hang onto the throttle.
  • At 10:36 one can see the timing and then just a quick rev where I checked for any movement. The result was basically identical to the previous test. Same position on the timing disk, and no change on throttle.
  • At this point, the GoPro app had the clips in the wrong order and one can see the bike stalling in my driveway at home.
  • Then I packed up and was unable to start it. I pulled the plugs and then swapped them. Still no kick start but I got it started on the slope leading back down.

The bike ran very badly and it really only ran at all with the choke on. It vibrates a fair bit as mentioned previously. There is a lot more video of it banging and popping. I checked plugs earlier on. The lower one was black and wet around the edge, but dry and lean looking in the middle. The other was very sooty, sticky and also a little wet.

The only thing I noticed was that the upper pipe had now also become very blue, same as the bottom one previously. I then actually tried switching the polarity of just that pickup just in case it made a difference. It didn't

At this point I'm resigned to swapping my old original pickups into the new cover. I know of a guy up North who has the factory calibration tool and so I could at least get things back to how they were. The new pickups are the only thing that is actually new in this equation and so I really need to take them out of it. It's just weird how they work, but they don't.

I'm interested in knowing if there is anything mechanical that might cause this sort of problem. I can't see how, but I'd like to be able to exclude any other possible causes. Even with these issues, the engine felt very strong when I briefly opened it up, so I can't imagine it having any such issues.

Thanks again for any comments.
Rob
 

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Hi Rob,

It's a pig of a situation. You know the golden rule about only changing one thing at a time? Unless you know that the ignition system is working perfectly, then it would not be wise to look for other causes...... the carbs can suffer from gummed up idle passages after being left standing for a long time, which will spoil the low speed running, but I'd be reluctant to get involved in anything else until the ignition is fully sorted. It sounds like a good idea to get the original pick-ups refitted, as long as you know for sure which wire went where. If you can get the bike running correctly then you can think about balancing the carbs.


Colin
 

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Discussion Starter #12
Thanks Colin

I've got the pickups out of my old cover and will pull the new cover off this weekend. It's the only way really.

I'd like to find a good set of NOS pickups.. but that ain't gonna happen!
Rob
 

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In the long term Rob, you might want to switch to a new ignition system like the Sachse, which is easy to fit yourself.
 

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Rob, This may be too late but I received an email from a bloke in Sydney looking for an old regulator yesterday and it piqued my memory. This is a long shot but with older Ducatis you never know sometimes. Here's what he said -

"I had a problem the last few weeks with my GT the bike starts 1st kick, warms up and after some time idles, once warmed up at speed open throttle, seems like it starves for fuel then back on again, I tried to find the problem within my capability, so took to shop.
This bike has been fully restored including a complete rewire, it runs Dyna S electronic ignition, 5 omh coils and leads, also replaced the stock with regulator (see attached) recommended by Bevel Heaven for this model, long story short all checked out ok with the exception the load test showed battery needed to be replaced, charge rate on new battery was poor so to test we swapped the new regulator for my stock used Sport regulator...test, charge rate great, test ride so far problem solved!"
 

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Discussion Starter #15
No, not too late yet!

Thanks for posting this. I'm reading that it had a faulty or otherwise inadequate regulator and when he swapped to the original, it worked.

Mine has a correct as-new regulator, and it ran with that regulator before all this drama. However, I also have the original regulator in a box that came with the bike so I can always compare with that. I'll look into checking the charge rate as part of getting it going again. The battery is a new one and I topped up the charge before running it.

At this point I've just received my pickup adjustment tool in the mail and am ready to pull the clutch cover off and swap to my original pickups over. I decided I really had to do it myself so I can be certain it's all correct. This Brancato tool will also work to adjust the pickups I got from Britz and pretty much any pickup, so I'll be sure to check how those were set up before I remove them.

I'm feeling about 50/50 that it's going to be fixed or be the same. If it's the same then I'll get into the rest of the electrics.

I'm unsure if I can do it this weekend. Might have to be next!
Rob
 

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Discussion Starter #16
Just an update on this process...

I've pulled the clutch cover off and have checked the new pickups against a Brancato tool. I couldn't face sending it off to someone else to adjust.. I had to see it and do it myself. So I bought the tool after looking closely at the pix and determining that it can be used to check any pickup, not just the originals.

The attached images show how the horizontal pickup has large gap, over 1mm, whilst the upper pickup actually touches the device. With this tool, one has to adjust with the required gap of 0.05 to 0.10mm applied. The angle was pretty close for both pickups.

So this is obviously not so great!

I'm left with the dilemma of either adjusting the new pickups and putting it back together, or replacing them with my originals. I'm still leaning towards putting my old ones back in and have redone the sleeve. I'll install it tomorrow once I've cleaned up all the gasket crap.
Rob
 

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I would try adjusting the new pickup and give it a go. Too close[or no] clearance will cause a no advance/too much advance, backfire and kick back. That touching pickup is likely been your problem all along.
 

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I'd agree with that too Rob; the Japanese pick-ups may be superior to the old originals. Maybe reset them and see how it goes, you can always swop they later if need be (easy to say, but more pain!).
 

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Rob, For what it's worth I'd adjust the pickups to the wider end of the spec. Had an Allazura that popped and farted like crazy when starting and going to the wide end of the spec. improved its manners so much it acted like a Japenese bike!
 

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Discussion Starter #20
eek, I'd already gone ahead and swapped over to the originals before I checked my email today.

I got them down to 0.06mm vertical and 0.07mm horizontal. It's fiddly because torquing everything up squeezes the gaps together a tiny bit and so I had to start a bit further out.

Overall the original backing plate and screws are sturdier than the replacement was. The latter turned out to be sitting on top of a couple of aluminium spacer disks that were necessary because of the way the new pickup base plates hit the mounting pillars in the case. A couple of the images are that pickup.

Another thing I also confirmed is that my originals are in fact marked incorrectly on the leads. The O is the V and the V is the O. This was something I'd suspected when I first pulled it apart way back. I'll redo the plug tomorrow and switch the maker bands over.

I aimed for the middle of the range for the gap, and it's all quite tight with little room to spare. It's all tightened up now, but I could readjust them out to 0.1mm if that is really worth doing? Three of the images show everything tightened up as it is now.
Rob
 

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