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V50 no spark

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Woodpecker View Drop Down
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    Posted: 29 Jul 2021 at 14:22
Can anyone help? Yesterday the bike started without problems today it wouldn’t start. I thought i had flooded it so took the plugs out and cleaned them and also tested for a spark nothing on both plugs.
I am struggling to sort it out the wiring diagrams i have are hard to read any suggestions please.
Stuart
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Dave P. View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Dave P. Quote  Post ReplyReply Direct Link To This Post Posted: 29 Jul 2021 at 14:50
Looks like it could be the low tension (12V) supply to the coils from the ignition switch. Do other electrical items work? Check that you have voltage at the coils first. Oh yes, and the kill switch presuming that you have one.

Edited by Dave P. - 29 Jul 2021 at 14:57
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Richard Hyatt View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Richard Hyatt Quote  Post ReplyReply Direct Link To This Post Posted: 29 Jul 2021 at 15:56
As said above, check for 12v at both coils , they come off a common supply.
Maybe daft , but check kill switch.

Once both coils have 12v then you're looking at the triggering side of both coils , which comes from the modules under the side panels, and they're switched from the sensors behind the generator
See what you have and don't have first
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Dave P. View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Dave P. Quote  Post ReplyReply Direct Link To This Post Posted: 29 Jul 2021 at 16:10
I believe some V50's had points and others electronic ignition, this could be relevant ??
TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST.

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1970 T120 Bonnie. 2009 500 Bullet.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote AdrianW Quote  Post ReplyReply Direct Link To This Post Posted: 29 Jul 2021 at 17:24
My understanding is that early models had electronic ignition. The V50III (same design as my V35II !!)
came with points..
I am not sure if the very early ones made it to the UK, from memory I think it was the "II" that came here and I am not sure what these have but maybe still the electronic ignition.
You need to get the front cover off to be sure.. !

Something sudden like this I would be looking for a loose / broken connection.. I too would check the kill switch, the switch units aren't the best quality.....
If you have NGK plugs and they are fairly new try some others - there were a batch of duff ones going around but I doubt both would fail at once..

Good luck..

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Grandadandy Quote  Post ReplyReply Direct Link To This Post Posted: 29 Jul 2021 at 18:15
To confirm, V50II has electronic and V50III has points ignition.

Andy
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Brian UK View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Brian UK Quote  Post ReplyReply Direct Link To This Post Posted: 29 Jul 2021 at 18:47
You will find the V50 in the UK too, and it had the Bosch ignition too.
Brian.

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Woodpecker View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Woodpecker Quote  Post ReplyReply Direct Link To This Post Posted: 30 Jul 2021 at 19:12
Many thanks to you all for your suggestions. Problem now solved after several hours checking through wiring diagrams. it was the ignition switch not fully connecting with its contacts. The lights came on but no contact so no spark!
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Simond View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Simond Quote  Post ReplyReply Direct Link To This Post Posted: 30 Jul 2021 at 19:29
Interesting comment above re NGK plugs

Finally chased misfire & crappy idle to dodgy, but brand-new plug.  

I was so sure it must have been something else that it took ages to find…
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Ken-Guzzibear Quote  Post ReplyReply Direct Link To This Post Posted: 31 Jul 2021 at 09:40
I started to pass on NGK plugs I go to "Green Spark" moved to Bosch plugs had 2 NGK fail from the get go

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Post Options Post Options   Thanks (0) Thanks(0)   Quote iansoady Quote  Post ReplyReply Direct Link To This Post Posted: 31 Jul 2021 at 10:40
Were those NGKs from Green Spart Ken? I've always trusted them to sell the kosher stuff.
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Simond View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Simond Quote  Post ReplyReply Direct Link To This Post Posted: 31 Jul 2021 at 11:42
Just in the shop with one of the cars, chatting to the mechanic, he said there was a time when he’d change a set of plugs and one of them would always be duff.  He ended up refusing to fit NGKs, though he said that it was a few years back.

I’ll see what Guzziology says
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Keef Mayhem Quote  Post ReplyReply Direct Link To This Post Posted: 31 Jul 2021 at 11:46
Ian
I’ve had at least 6 recent NGK plugs fail very quickly on my T140 Bonnie, wondered if I had some dodgy plugs so bought the last 4 from Padgetts, absolutely rubbish, half a mile from home before the first one stopped firing, so I bought some Champion N5Cplugs and it’s not missed a beat since, I won’t fit NGK’s to my old bikes now !
So many bikes, so little time !
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Gianni Quote  Post ReplyReply Direct Link To This Post Posted: 31 Jul 2021 at 12:37
Originally posted by Woodpecker Woodpecker wrote:

Many thanks to you all for your suggestions. Problem now solved after several hours checking through wiring diagrams. it was the ignition switch not fully connecting with its contacts. The lights came on but no contact so no spark!

IIRC the V50 had the same ignition switch wiring protocol as the larger Tonti bikes.

This was:
 - red = power in from battery/rectifier (unfused)
 - white = out to ignition circuit vis kill switch (unfused)
 - green = out to fusebox and thence to parking light circuit (fused)
 - brown = out to fusebox and thence to the remaining circuits (all fused)

It is possible to gently prize the crimps off the bottom of the ignition switch and get inside for inspection and cleaning. May be worthwhile if you want to keep the same key as it probably matches the petrol cap. Otherwise I would recommend a new switch as it is a potentially hazardous single point of failure - consider what loss of ignition power might mean in the outside lane of a motorway (he wrote from trepidatious experience).
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Brian UK Quote  Post ReplyReply Direct Link To This Post Posted: 31 Jul 2021 at 13:06
First thing to do is spray some electrical contact cleaner liberally into the keyhole and operate the switch several times.

Different model, I now, but had exactly the same problem on my Norge, turned out to be the inline connector to the loom, and the "white" wire wasn't making contact. Cleaned the connector and all was well again.
Brian.

Better 5 minutes late in this world than years early in the next.
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