1spark only

[zedhead]

Hi Folks!
My 1VJ did me proud on the Isle of Man last week. Great on the little roads and a waterlogged campsite! But so reluctant to leave the island it packed up as I boarded the ferry with a huge backfire!
I get 1 spark when I spin the motor on the starter. 1 spark as the motor initially turns over then nothing! Just in case it was the ignition coil I got a new one for £11 off eBay but just the same. Now bewildered. Anyone have a clue? Cheers, John.

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[xtrider]

You'll need to test your stator , pulse gen(pick-up coil) , or cdi . Chances are good it's the pulse gen that isn't sending all the sparks to the cdi , they are getting old and tired . It could be any of the three though . If you know someone that can borrow you a good cdi it would quickly eliminate it since you can't really test them . The pulse gen needs a peak volt meter to test properly and see what volt it is sending , my guess it can only muster one shot each attempt .


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[zedhead]

Thanks I've got a max min function on my multimeter and I'll do just that.

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[zedhead]

Don't know anyone local with a 1VJ (Warrington or 30 miles radius anyone?) I guess I'll buy one on eBay and resell it if needs be... At least there seem to be ones around!

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[motorang]

It may be much easier and cheaper than that. Possibly just the float is stuck, and you got one ignition before the spark plug clogged up and died.

If that is fresh, kicking/starting over with fuel tap closed and full open throttle may lean the mixture enough to bring the engine back to life. Abou the equivalent of 10 kicks FOT, then normal or only slightly open throttle. Open fuel tap when engine starts.

If this is not fresh, get the spark plug out and give it a dry/clean. Kick over severeal times with fuel tap closed and full open throttle cleans inlet and burn chamber of excess fuel. Put spark plug back and try starting as normal, then open fuel tap when engine starts.

Andy

[zedhead]

Thanks for that. When I say 1 spark, it's 1 spark at the plug, removed from the cyl head and well earthed. I thought laying it on the engine may not be enough so clamped it well and still just the 1 spark. So not fuelling. I've found a wiring diag that indicates three cables come from the stator pickup, so I'll look for signals from these. I guess I can turn the engine over and look for peak at the 3 combinations, then do the same after the first rotation to see if anyhing has died away... 1st chance to get at it for a few days so here goes...

[zedhead]

OK for anybody interested here's the happy news, I found a wire that had come away from a 2 pole plug/socket connector. There was one wire connected to either side, one must be a redundant one from the CDI, it fooled me because one wire either side looked ok. Should have noticed the remaining connected wires weren't on the same side of the connector! Don't know what the lost connection was but it didn't stop the starter or the first spark. The healthy condition now gives sparks that aren't as bright as the initial one before, strangely enough. New plug was fitted and the engine runs better for it. Happy as a pig in sh!t to get my bike back!

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[xtrider]

It was the second pulse from the pick-up coil probably that the wire wasn't hooked up . These bikes need both signals to continue sending spark after the first one . The cdi counts time since the last spark for sending the next spark at the correct advance , depending on rpm (time between the first and second signal). If there is no second signal it can't send another spark since it doesn't know the rpm of motor. Hope that makes sense.



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[firestarter_phil]

Sorry to drag up an old post - but I am hitting the same situation as this and I am trying to work out where my issue lies.

I ended up with some a spaghetti juntion of connectors going on the old loom and have tried to tidy things up but still have an issue where on pressing the starter, I get a single spark and then nothing more.

Looking at the wiring diagram below we have the Red and Brown coming from the CDI magento and then the three other wires GR/Y, GR/W & BL/Y



Does anyone happen to know which of these are managing the pulses for intitial and then subsequent sparks?

[charliext1vj]

the 3 tagged wires are for the pulse.

picking any pair of these at random to measure ohms you will get (WIRE 114 ohms [WIRE) 114 ohms WIRE] and therefore 228 ohms across 2 coils if you pick that.
These are approximate readings and subject to quality of multimeter too.

The Red and Brown associated with power.

In my amateur experience if the source coil wires are complete and suffering no partial breaks and read as above they are probably ok.

I would then look at CDI at the quality of Orange wire, coil and the grounding both of the stator cover and the CDI sometings its worth just running a wire to be sure.

It then gets more interesting but in short you have to make sure the blue wires are not going to ground incorrectly through any of the clutch, side stand , cut off switches. You can remove them of the circuit.

As well as checking the cutoff relay.

hope this is of use