Timing Strobe Help!

[PPuxley]

Originally Posted by Darkness

I see you have an original pattern slave cylinder with ‘Hydraulic Clutch” on it. They are getting a bit rare now.

Would be especially special if it was on a bike that worked 🙄

[Darkness]

Originally Posted by PPuxley

Would be especially special if it was on a bike that worked ��

I have every confidence you shall soon have it working Patrick, it’s just that you are still waiting on the “light bulb” moment when it becomes obvious what’s wrong!

[PPuxley]

I hope so.
I found this yesterday. Exactly the same issue with the strobe not working at revs (although on horizontal ). Annoyingly the comments dont seem to resolve the issue. There was some suggestion that it was the plug cap, but it isnt followed up. And in my case that seems an unlikely cause since I have swopped coils caps and leads together and the fault remained on the vertical.

Video of strobe not working

[PPuxley]

More wierdness!

I corrected the slightly advanced timing as shown in the photos above, by retarding the whole plate, since both cylinders were showing nealy the same advance.

Restested and the horizontal is spot on , but the vertical is still the same state of advance, ie appears not to have changed.

Unsurprisingly, because Ive done nothing to change it, the strobe remains non functioning above idle on the vertical, and the vertical plug remains wet.

[Mr Gazza]

Is it possible to get a meter on the pick up cables while it's running?

I'm not sure if what I'm suggesting is even possible? I don't know what sort of current you would be looking at nor how to measure it, and probably rather difficult as it would be pulses, not a flow.
Beyond going to all the trouble of lengthening the cables to swap them I don't know what to suggest, except I really do think it's the vertical pick up failing to work at anything over tickover.

[jerry]

This really does seem like exactly the same issues I am having on my M750????? we need to solve this puzzle

[PPuxley]

I watched Brads video of the replacement of some Bosch pick up coils with a Yam CY-7 replacement.
I know this was as replacement in an older Bosch pick up system but wondered whether it was an option in the Kokusan pick upped one.

The issue maybe that CY-7 coils have a 200 ohm resistance where the Kokusan have 100 ohm. Now I dont know whether that matters- maybe the Bosch units were also around 100 and the CY7s worked in that situation, so that coil resistance might not be critical. Anyone know what the Bosch units were?

But for 20 quid it might be worth a trial.

Brad's Video

[PPuxley]

Brad replied to the post above when posted as a comment to the youtube video on his channel.
He has used P08 pick ups supplied by Electrex World as replacements, these are 460 ohms, so CY-7s at 200 ohms should not be a problem

[PPuxley]

I went up to Electrex World which is just up the road at Stoke Row, to pick up a pick-up.
They sell a replacement for Ducati kokasan for £36.
https://www.electrexworld.co.uk/cgi-...2ehtml#SID=403

I had a long chat with one of the techs about the issues I was having and his view was that it was highly unlikely to be the pick up coil.
"They either work or they dont"
On the subject of coil impedance, he said it wasnt the coil impedance that was critical, but its inductance, and inductance can be achieved by various combinations of winding thickness and turns, hence why coils of different resistance may still work.
OEM resistance is 100 ohms, whereas these replacements are 460 ohms.

The upshot of the conversation is that only leaves the vertical carb as the culprit having swopped everything else (and it being unlikely to be the pick up.)
So the carbs will be coming off again tomorrow for another really good look in the LH one.

And hopefully another trip to Electrex World to return the pick up unopened.

[Davy]

So so close patrick Got to admire your perseverance, which I’m sure will pay off. Did you try another set of carbs out of curiosity.

[PPuxley]

Originally Posted by Davy

So so close patrick Got to admire your perseverance, which I’m sure will pay off. Did you try another set of carbs out of curiosity.

Not yet! but Ive just been talking to a local mate that has a set that he replaced because he obtained another set at a good price. So even if his old set are not right, just replacing my vertical one with something different, and seeing a change......or not, will indicate whether my carb is the problem.....or not.

[jerry]

problem is Patrick im having similar problems with the M750 and for months i was convinced it was the carb ,, but thats Definitely not my issue , the carb works fine on other bike ,, its now looking definitely as an ignition timing issue ,, pickups are testing fine at 100 ohm and the coils and ignighters are fine ,, so Im still baffled bike runs but really crappy no air leaks or mechanical issues .

[PPuxley]

Originally Posted by jerry

problem is Patrick im having similar problems with the M750 and for months i was convinced it was the carb , but thats definitely not my issue , the carb works fine on other bike ,, its now looking definitely as an ignition timing issue ,, pickups are testing fine at 100 ohm and the coils and ignighters are fine ,, so Im still baffled bike runs but really crappy no air leaks or mechanical issues .

OK, Jerry, some progress this morning I think or confirmation of something I had found already
Agree, I dont think its the carb.
This morning I borrowed a Gunsons colourtune.
When used on the vertical cylinder I get a good colour at idle, but as soon as I raise the revs the spark stops (no colour)
This confirms exactly what I get when I try to use the strobe on the vertical cylinder- the strobe stops working above idle.
So it is definitely a breakdown that is causing no spark at anything above idle........but why????
Ive swopped coils and leads and ignition units between the cylinders and the fault remains always on the vertical.
By a process of elimination that leaves the only unchanged things, the Pick up coils and the low tension wiring to the coils and ignition units. BTW my coils and pick ups test fine for resistance, like yours.
So despite being told its unlikely to be the pick up coils ("They either work or they dont"), I think thats where Ive got to go next.
But, Jerry have you done anything with your pick up coils that would scotch this idea?

[PPuxley]

I think I have just elimanted the coil low tension wiring
I swopped the pick up wires between the ignition units and swopped the HT leads front to back
Fault remained on the back/vertical cylinder.

[jerry]

No I have not done anything , to the pickups ,, i think I may buy one or 2 just for ,,er peace of mind or desperation ha ha ,,I am borrowing a strobe from a mate to see if its out of synch ???? I also have a colortune ,, but they can be awkward to understand what one is seeing

Originally Posted by PPuxley

OK, Jerry, some progress this morning I think or confirmation of something I had found already
Agree, I dont think its the carb.
This morning I borrowed a Gunsons colourtune.
When used on the vertical cylinder I get a good colour at idle, but as soon as I raise the revs the spark stops (no colour)
This confirms exactly what I get when I try to use the strobe on the vertical cylinder- the strobe stops working above idle.
So it is definitely a breakdown that is causing no spark at anything above idle........but why????
Ive swopped coils and leads and ignition units between the cylinders and the fault remains always on the vertical.
By a process of elimination that leaves the only unchanged things, the Pick up coils and the low tension wiring to the coils and ignition units. BTW my coils and pick ups test fine for resistance, like yours.
So despite being told its unlikely to be the pick up coils ("They either work or they dont"), I think thats where Ive got to go next.
But, Jerry have you done anything with your pick up coils that would scotch this idea?