31K No spark

[element137]

Hi all, apologies for long question - 
Been stuck in a no spark rabbit hole for a couple of weeks and looking for some advice -
So for context - brand new aftermarket loom - brand NOS ignition switch - new plugs/caps - all other electrics are OK - lighting circuits, indicators, clocks, power valve cycling OK so just leaves ignition-
2 years ago on original loom, CDI, stator, coil and ignition switch it was running - albeit never road tested as it was just  run to see if I could start it - which was all OK-

So fast forward - almost finished rebuild - brand new battery - new loom all connected up- lighting circuits sorted ( eventually ) but no spark-

So far tested stator ( low and and high speed windings ) High speed at 5.4 ohm - low speed at 237 ohms - pick up coil at 112 ohm - so these look OK -
Coil was not the best though - so replaced with new - new one all in spec -

Fitted new coil - still no spark - thinking now CDI is shot - but its literally just been sat in a box in a spare bedroom for two years - and was working before I stripped the bike - 

Just to eliminate if its Ignition switch or kill switch problem - tonight I did the following tests on IGN switch and kill switch -
Battery connected and fully charged -
Tested for Continuity first from Black and White wire from CDI to loom , earthed to a head bolt-
Results
IGN ON and Kill ON = no continuity
IGN ON and Kill OFF = continuity
IGN OFF and Kill OFF = continuity

Tested for Resistance ( using 200 ohm on multi-meter)
IGN ON and Kill ON = 1 ( open circuit ?) 
IGN ON and Kill OFF = -00.4
IGN OFF and Kill OFF = 00.6
IGN ON and Kill OFF = -00.5

I am have very limited knowledge on electrics - so is the behaviour of the IGN and kill switch as expected ?- and if so, with the stator resistance test looking OK-  is this deffo pointing at CDI failure ?
Any help be greatly appreciated -

[linx]

Is the engine earthed?

[midlifecrisisrd]

And the coil is earthed to the frame

Steve

[element137]

Coil is earthed to the frame - and the black earth lead too - on the lower coil connection - I ground away some of the powder coat on rebuild to ensure clean contact to the frame where the earth lead the and coil attach - so I assume that be OK ?

[linx]

If you have a multimeter, just make sure the spark plugs are earthing.

[crigar]

Ne pas oublier de relier la masse entre le moteur et le châssis. Il n'y a jamais trop de fils de terre.

[element137]

May 19, 2023 7:48:04 GMT 1 linx said:

If you have a multimeter, just make sure the spark plugs are earthing.

what is the method for testing that please ? - apologies if its a stupid question - electrics way out of my skill set - 

[element137]

May 19, 2023 8:05:46 GMT 1 crigar said:

Ne pas oublier de relier la masse entre le moteur et le châssis. Il n'y a jamais trop de fils de terre.

additional earths from engine to frame ? - why would it need that please ? -  

[linx]

May 19, 2023 8:35:43 GMT 1 element137 said:

May 19, 2023 8:05:46 GMT 1 crigar said:

Ne pas oublier de relier la masse entre le moteur et le châssis. Il n'y a jamais trop de fils de terre.

additional earths from engine to frame ? - why would it need that please ? -  

Because the engine might not be getting earth through the frame. Especially if the frame has been powdercoated.

[linx]

My wiring loom has an earth lead for the engine.

[element137]

May 19, 2023 8:49:29 GMT 1 linx said:

My wiring loom has an earth lead for the engine.

the current Loom has a black earth that runs to the coil/frame connection point - the old OEM loom had this also - the earth has a ring connector which the coil bolt passes through - when I stripped stripped the bike down not aware of any other earths to the engine ? - where does your connect to/from please ? - thanks for the suggestions, I appreciate any help I can get on this - 

[linx]

May 19, 2023 9:18:15 GMT 1 element137 said:

May 19, 2023 8:49:29 GMT 1 linx said:

My wiring loom has an earth lead for the engine.

the current Loom has a black earth that runs to the coil/frame connection point - the old OEM loom had this also - the earth has a ring connector which the coil bolt passes through - when I stripped stripped the bike down not aware of any other earths to the engine ? - where does your connect to/from please ? - thanks for the suggestions, I appreciate any help I can get on this - 

Originally it went to a crankcase bolt. However since I put the engine back in last week, I have put it under one of the screws on the back of the head that hold the coolant stub on. Removed the paint under it first. I also have the earth for the frame under the coil.

[chrisg]

May 19, 2023 8:34:15 GMT 1 element137 said:

May 19, 2023 7:48:04 GMT 1 linx said:

If you have a multimeter, just make sure the spark plugs are earthing.

what is the method for testing that please ? - apologies if its a stupid question - electrics way out of my skill set - 

There are no stupid questions, just questions. This is how we learn. Electrics are my weak point, but keep trying. Good luck.

[linx]

May 19, 2023 10:42:19 GMT 1 chrisg said:

May 19, 2023 8:34:15 GMT 1 element137 said:

what is the method for testing that please ? - apologies if its a stupid question - electrics way out of my skill set - 

There are no stupid questions, just questions. This is how we learn. Electrics are my weak point, but keep trying. Good luck.

No problem. If you have a multimeter, just check you have continuity between the battery -ve terminal and the spark plugs.

[element137]

Thanks - will test between the battery and spark plugs tonight - appreciate the help - I am probably at some point going to ditch the CDI, but at this point in time I just want to rule out anything else - before I introduce another variable to the problem- last thing I want is to go zeel or igni route and still find its a problem - so trying to eliminate everything first before junking CDI -

If I wanted to run additional earths - to ensure engine is adequately earthed, I could run from battery (-ve) to a bolt on the engine for example ? , or run from engine to frame ? was thinking I could just do this a temporary test with wire /croc clips ?

[JonW]

Do some checks on the ignition switch to make sure its bridging correctly at the connector, same with the kill switch, using the wiring diagram as they are on there. These have been known to be an issue.

You can also test the cables down through the loom and make sure there is continuity as expected as its possible a new loom could have an issue, it happens.

And yes borrowing an CDI isnt a bad idea, it will tell you quickly if that is the issue. the version you have is know to go bad, its the only one in our bikes known for this.

HTH.

[midlifecrisisrd]

Unplug the iggy switch and the RH switch to eliminate kill switches

It will run without them but no light or anything and pv controller won't cycle

My concern is the new loom


I'd disconnect the plug to the loom from the cdi and run a separate wire from the orange to the coil and a black to an earth

Steve

[element137]

Thanks all for teh help so and suggestions so far - so an update from this morning - just to ensure engine earth OK - did the following tests this morning-based on below - seems earth is OK ?

Battery Connected - IGN = OFF
Test Light connected to Battery (+ ve )
touched to to coil connection = lights up
touched to a head bolt = lights up
touched To both LH and RH spark plug = lights up

Resistance and Continuity
Battery (-ve) with multi meter set to 200 ohms
Connect to coil connection = 00.5 and continuity bleep OK
Connect to head bolt = same as above
Connect to LH/RH Spark plug = same as above

Voltage
Battery ( + ve ) multi meter set at Voltage
Battery (- ) to (+ ) = 12.5 v
Battery (+) to coil connection = 12.5 v
Battery ( +) to head bolt - 12.5v
Battery (+) to both RH/LH spark plugs = 12.5v

I am hoping this eliminates its inadequate engine earth ? - so if anyone can confirm if the test results I got from the IGN and kill switch are indicating normal condition please ? - if they are, then can only now be the CDI ?

[element137]

May 20, 2023 10:44:04 GMT 1 midlifecrisisrd said:

Unplug the iggy switch and the RH switch to eliminate kill switches

It will run without them but no light or anything and pv controller won't cycle

My concern is the new loom


I'd disconnect the plug to the loom from the cdi and run a separate wire from the orange to the coil and a black to an earth

Steve

Thanks Steve- appreciate the help- if I do this as you suggest - what am I testing for please ?  - I assume this this eliminate  the IGN and kill switch from the problem ? - would I then do plugs out, earthed them , kicked over and look for a spark at the plug ?

[midlifecrisisrd]

Yes, disconnecting the switches will rule them out

Disconnecting the cdi plug with the black, black/yellow, black/white and orange then earthing the black wire and running a separate wire from the orange on the cdi to the coil positive will check the cdi is actually getting a 0v connection, the loom kill switch wire isn't shorted out and that the coil feed has continuity

Steve

[element137]

May 20, 2023 15:40:38 GMT 1 midlifecrisisrd said:

Yes, disconnecting the switches will rule them out

Disconnecting the cdi plug with the black, black/yellow, black/white and orange then earthing the black wire and running a separate wire from the orange on the cdi to the coil positive will check the cdi is actually getting a 0v connection, the loom kill switch wire isn't shorted out and that the coil feed has continuity

Steve

Thanks Steve -that be the next  job for me in the morning - much appreciated 

[element137]

Many thanks for the help/suggestion so far - on what is a frustrating fault finding task - Had another good go at this yesterday - still no spark - did what Steve suggested - disconnected RH bar, kill switch and 3 way black- disconnected the IGN switch - disconnected CDI from loom - earthed the black in the CDI side connecter, ran a jumper cable from the orange on the CDI connector to the orange on the Coil - made sure the spark plug deffo earthed to the engine, kicked over - still no spark -
Checked continuity on the lead connecting orange CDI end to orange coil end - and it was was OK for continuity - testing voltage it showed 0v
Then checked voltage from battery (+ve)
Battery was fully charged (12.68V across it) - ran Bat (+) to coil connection ( the earth point ) = 12.68v - Battery (+) to spark plug = 12.68V

Whilst I had the RH bar controls off - tested the kill switch - all seems fine - in ON position = no continuity between black and black/white wire - when in OFF position - continuity between the wires - so I am assuming this is how its supposed to function ? - checked all the IGN wires going to right place in the block connecter vS wiring diagram = all OK

So - unless anyone can suggest anything else I can test - I am thinking it must be CDI ? - I am going to have an enforced break from it as I have to go on holiday - but it looks like only way to test is either swap with a known working CDI OR replace it ? - is there anything else I can check before I chuck a cover over it and forget about it for a few weeks ? -

[midlifecrisisrd]

Afraid now you can only borrow and try another cdi

Steve

[element137]

May 22, 2023 8:57:39 GMT 1 midlifecrisisrd said:

Afraid now you can only borrow and try another cdi

Steve

Thanks for you help and input along the way anyway Steve - its much appreciated - electrics well out of my skill set - a frustrating problem with limited skill to resolve is a recipe for giving up ! - 

I'll have a break, and start again, I always knew the CDI would have to be replaced at some point  just to ensure some future reliability(its an early 29K -50) - I am gutted as I have sunk two years in to the bike so far , I am about 90% done , itching to get it started - and then a showstopper like this - all part of the challenge I guess - anyway,  to be continued ........

[chrisg]

May 22, 2023 9:14:05 GMT 1 element137 said:

May 22, 2023 8:57:39 GMT 1 midlifecrisisrd said:

Afraid now you can only borrow and try another cdi

Steve

Thanks for you help and input along the way anyway Steve - its much appreciated - electrics well out of my skill set - a frustrating problem with limited skill to resolve is a recipe for giving up ! - 

I'll have a break, and start again, I always knew the CDI would have to be replaced at some point  just to ensure some future reliability(its an early 29K -50) - I am gutted as I have sunk two years in to the bike so far , I am about 90% done , itching to get it started - and then a showstopper like this - all part of the challenge I guess - anyway,  to be continued ........

I can feel the frustration in the txt, but when it does go, you will so happy, like youve just pulled the best bird in the pub 🥳

[Gitram]

When you say no spark, have you kicked the engine over in a darkened garage, or anywhere else that you can cut out all light? the reason is that while there may be no spark visible in daylight there may be a tiny wee glimmer of one when doing the same in a pitch black location and while i ain't an electronics expert that would suggest to me that everything is working but the capacitors inside the cdi are not holding a charge, they are about 40 years old so.. anyway, i have had similar issues so substitution with a known good one sorted it out..

marti

[element137]

May 23, 2023 11:28:22 GMT 1 Gitram said:

When you say no spark, have you kicked the engine over in a darkened garage, or anywhere else that you can cut out all light? the reason is that while there may be no spark visible in daylight there may be a tiny wee glimmer of one when doing the same in a pitch black location and while i ain't an electronics expert that would suggest to me that everything is working but the capacitors inside the cdi are not holding a charge, they are about 40 years old so.. anyway, i have had similar issues so substitution with a known good one sorted it out..

marti

Yeah - kicked over in the garage with all the lights off-used a torch to get myself to the bike- haha - nothing happening on the spark front even in the dark 

[jessy03]

Where are you located? Someone might be able to loan you a CDI for a few hours.

[element137]

May 23, 2023 14:38:24 GMT 1 jessy03 said:

Where are you located? Someone might be able to loan you a CDI for a few hours.

I am in near Birmingham - I am going on holiday end of this week- so plan was when I get back - either put out an appeal for a loan CDI to rule it out  - or just bite the bullet and go down the zeel route - I fully expected to have to junk the CDI off at some point - so this may have just bought it forward - I am pretty sure with what I done so far its isolated it to a CDI problem  - but I never 100% sure as my electrical knowledge not the best - it was working , two years ago, albeit for very brief start up after standing for years- 

[jessy03]

I’m in kingstanding on Thursday/Friday with work, if you’re not too far away you could try mine, I’ll be travelling south after to Northampton.