No Spark

[sweller]

Just walked over to my workshop to pick up my Tiger - it's a two mile walk from my house - and the bloody thing won't start...  Oh, the joy of a two mile return walk in the rain.

Anyway, there's no spark at any of the plugs, there is 12v at each of the coils.  There appears to be continuity on the wiring to and from the black box and crank position sensor.  I measured 0.563 ohms (on the 2K scale) through the crank sensor.

Now, the funny thing was last Saturday the bike developed a misfire which I put down to wet electrics but when I investigated I noticed a missing rubber cap on one of the carb balancing spigots - this was replaced and I also checked the sparks which were very weak.  I changed two of the coils to known good ones which improved matters but it still wasn't perfect.  I also balanced up the carbs whilst I had the tank off and was generally messing about.

After all this it seemed to run ok so I then shut the door on the bike and left it until this evening and now no dice.

So, how do I test the crank position sensor and the igniter box - or does anyone have any ideas or experience?

[Mustang]

try jumping the side stand switch first .............it will crank but won't fire .
kill switch..........it won't crank or fire
clutch switch..............won't crank or fire

testing the crank sensor when it's cold will usually confirm nothing as they will usually put .6 ohm when cold but die when hot . 

[sweller]

Thanks, I'll try that - it'll crank quite happily, just no spark.

My machine won't crank if the stand is down and it's in gear or is that the clutch switch having an effect?

[sweller]

Meant to add the bike was stone cold when I was trying to start it.  Not sure what relevance that would have on the CPS.

[windscreenman1]

Mine does that sometimes if I pull clutch lever she goes these can be temprementle cats
Sometimes they can be a bitch sometimes sweet I guess shes having a bad one mate 
With mustang
It will be something simple but we don't always look for the obvious
Does it have petrol ?

[sweller]

I'm off to do battle with it tomorrow - I'm rather hoping it's something simple (and cheap!)

It does have petrol (a full bloody tank, which is a bit heavy) and it is being delivered.  It definitely doesn't have a spark - not a trace of one.

The wiring diagram in my owners handbook shows three wires at the sidestand switch - any ideas which two I connect?

[sweller]

Right, following this afternoon's quite chilly work there's still no trace of a spark - no trace of Spring either.

I jumped the sidestand switch - the relay quite happily clicked when the ignition was turned on but still no spark.

There's 12v at the coil but there doesn't seem to be a signal telling it to fire. The only way I can see to test it is to substitute components (coils, CP sensor and black box).  I've changed the coils so next step is likely changing the CPS.

Is there any way to borrow/hire the ignition tester box described in the manual?

A bit of a pain and I've still got my valve problem to sort.

[sweller]

It LIVES!

Found a break in the red wire to/from the igniter box - this may also explain the earlier misfire as the wire deteriorated.

Burst into life shortly after fixing the break.

Hooray.

[Mustang]