NC30, wouldn't start.

[Icemaestro]

Not a fuse that's gone is it, and then occasionally coming together? Or one of the connectors on the rhs of the bike? I have a vague memory of my bike going dead with one of those not connected properly? Other wise trying a known good cdi?

Wait up - how are you checking the spark? Checked the kill switch?:-) it can get bumped.


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[magg]

As they say, you cannot fix something that aint broke. Next time it fails to start run all your continuity, voltage checks and connector checks frpm pickups to ignition control unit to coils. The Haynes manual is based on the common multimeter tests and checks all the component parts. The OEM service manual assumes access to test equipment that is service centre specific, while the Honda Common Service Manual has a better general test procedure.

[Burbage]

I think I have found the fault finally! Seems to be the wiring to the ignition module, if if press the wires down (as oriented on the bike) where they enter the module the engine stops, wriggle them and it starts. I removed the ignition module and checked continuity, thats OK. Now cannot get the fault to show itself, I wonder if my somewhat brutal fiddling has sorted out the a poor connection from the loom onto the modules PCB.

Hopefully its OK now, I'll refit the fairing panels and tgo for a ride.

One thing I would like to try is measuring the peak voltages in the ignition system, trouble is it needs a special "tool", anyone know of a way around this?

Thanks for the replies.

John

[magg]

Peak voltage testing is a factory short cut diagnosis aid to finding faulty components. Other traditional methods work as well or better on intermittent faults, as you yourself have found.

If flexing the wires at the ignition control unit has an effect, would suggest close examination of the connector contacts, specifically the wires for core fractures. Also resolder the connector pins at the PCB or at least examine the solder connections closely, they can have very fine fractures caused by excessive force during connector removal.

[Burbage]

The saga continues, made up something to check the peak voltages, low but that's probably my choice of electronic component.
From a cold start wriggling the wires going into the spark unit stops the engine and further wriggling allows the engine to start. But once the engine has run for a couple of minutes then no amount of fiddling with the wiring stops the engine!
Whatever the fault is it will stop a cold start most of the time until a quick tug on the wires then away she goes.
Any thoughts as to what might be happening?
John

[dgunthor]

hi, sounds similar to my issue - cold start sometimes cuts out after 2 mins, bump start fail then starts, fine after that.

where is the spark unit you are wriggling? I'll try that if it happens again

yesterday, cleaned oil from air filter, cleaned spark plugs and changed fuel - no issues this morning - will see if it starts later...

[Burbage]

I've just had the spark unit (the black box below the rear light) looked at by a guy who is brilliant with electronics while I still can, retiring in a months time so will lose access to guys like him! His view, after much probing is that it is a poor connection on the PCB somewhere, at a "microscopic" level. The heat (expansion) from being powered up for a couple of minutes cures the problem. His advice was to heat the PCB locally when the unit was in its "no start" state, locally with a hair dryer to see if that would indicate where the fault lies. Problem is that the bike now refuses to not start! She runs as well as ever, even had a 60 mile trip a couple of days ago, just perfect!
I have just ordered off Ebay a Chinese replacement spark unit, £45, I thought I'd give it a go. Anyone tried one of these?
John

[Burbage]

An update on my starting problems. Finally diagnosed as most likely a broken track on the ignition device PCB. If the bike would start then it would run reliably as soon as there was some heat in the PCB.

I bought a Chinese ignition unit off Ebay, fitted it, bike ran fine. Too good to be true, rev-counter didn't work. Tried to have a conversation with the seller, he had no idea what the problem was, would not (could not?) replace with a fully working unit so got a refund.

So, did what I should have done as soon as the problem occurred, bought an ignition system from Rick Oliver. He answered my questions promptly and sent a it equally as quick, great service, thanks Rick. Bikes running as well as ever, was going for a ride today, pouring with rain here so will wait till next week sometime, its great being retired!