Old 1977 Kawasaki Z400 cafe racer i bought won't start
Discussion
Odd one this,bike ran perfectly 3 days ago when i bought it.All i've done is rewire in a set of small indicators which work perfectly,and added new left hand swifchgear and loom,this was extremely easy,one multiplug and two single bullet connectors.
The wiring under the seat was a mess and really made it difficult to get the seat back on,so i instantly thought i had accidentally pulled something or maybe just moving wiring that hadn't moved in years??
Anyway,symptoms after i connected things up were i hit the starter and it just spun over,i suspected no spark,which was confirmed by pulling a plug and touching the head to check for a spark.
Then after doing that once i hit the starter again after double checking a few connectors now it's dead when i hit the starter???
So turned over with no spark,then quickly progressed to nowt at start button?Any ideas?Thanks.
The wiring under the seat was a mess and really made it difficult to get the seat back on,so i instantly thought i had accidentally pulled something or maybe just moving wiring that hadn't moved in years??
Anyway,symptoms after i connected things up were i hit the starter and it just spun over,i suspected no spark,which was confirmed by pulling a plug and touching the head to check for a spark.
Then after doing that once i hit the starter again after double checking a few connectors now it's dead when i hit the starter???
So turned over with no spark,then quickly progressed to nowt at start button?Any ideas?Thanks.
Are you sure the two bullet connectors on the switchgear are the right way around? Sounds to me like you've somehow grounded the ignition (magneto?) through the frame. I don't know anything about old bikes (nor new bikes) but I know that on old power equipment, the way to turn off the engine is to ground the magneto which kills spark and thus the engine. You could test by disconnecting the switchgear?
Edited by LunarOne on Wednesday 8th March 21:45
said:
It's just the quick progression from turning over with no spark to no turning over at all?Seemed odd.
Was working in really bright light checking for a spark yesterday,decided to shut myself in my garage with the light off and there is a faint intermittent spark,with the odd fat spark for good measure.
There's a 4 plug connector just after the starter relay and the plastic is a bit melted,i keep coming back to it but can't get it apart just now.
There's a 4 plug connector just after the starter relay and the plastic is a bit melted,i keep coming back to it but can't get it apart just now.
robbocop33 said:
voltage at battery is 12.6v,constant live to coil with ignition on is 10.8v.
That's not good. Likely there's a poor connection in that circuit. Try jerry-rigging a metre of wire straight from battery to coil. Leave everything else in place, just temporarily bypass it. Tardigrade said:
That's not good. Likely there's a poor connection in that circuit. Try jerry-rigging a metre of wire straight from battery to coil. Leave everything else in place, just temporarily bypass it.
Will one wire battery positive to primary positive on the coil suffice?ThanksTwolane said:
Have you checked the points and ignition timing?
Assuming its not been upgraded to electronic ignition.
That's my next port of call.Thing that blows my mind is it's amazing the timing,pardon the pun of this,you go to buy a motorcycle,it fires up off the button for the seller,you get it home it fires up off the button,next day,problems! Assuming its not been upgraded to electronic ignition.
I'm definetly going to cut out that dodgy connector plug if the bypassing to the coil shows up it is a wiring fault.
When unplugged the voltage at the lead going to the positive primary connection is 12.16v,voltage at battery at that time was 12.22v so seems ok?(it was a really cold night,battery usually 12.6v)
I've been told to wire direct positive feedfrom battery to the coil positive but i suppose that's pointless now since voltage is good at coil?
If the coil is getting a good supply yet producing a weak,intermittent spark does this lead to points being bad or coil being bad,can i narrow it down that much just now?Thanks.
I've been told to wire direct positive feedfrom battery to the coil positive but i suppose that's pointless now since voltage is good at coil?
If the coil is getting a good supply yet producing a weak,intermittent spark does this lead to points being bad or coil being bad,can i narrow it down that much just now?Thanks.
It's never good enough just to be able to see the voltage you expect - there needs to be current-carrying capacity in the connection, and the wire from the battery to the coil will ensure that for testing purposes. You can have all the voltage in the world, but with no current, you cannot do work - no power is generated.
LunarOne said:
It's never good enough just to be able to see the voltage you expect - there needs to be current-carrying capacity in the connection, and the wire from the battery to the coil will ensure that for testing purposes. You can have all the voltage in the world, but with no current, you cannot do work - no power is generated.
Ok,i understand,will try it,thanks!KTMsm said:
That sounds like the chief suspect !
I'd cut it out and replace it
I thought so too!Brown and melted outside,wires were really dry and powdery looking,cut them back,cleaned them,rejoined them and no difference!I'd cut it out and replace it
Had a look at the contact breaker points,turning over by hand they are opening and closing cirrect,gap,by eye looks hiw i faintly remember,however when turning the bike over and looking at the points sparking shouldn't it be a nice clean defined spark like a spark plug?
What i'm seeing looks very uncontrolled sparking and even little tiny flames about 1mm long getting thrown out to the side sometimes at the contacts gap!!
Can't remember what a good spark should look like but i think it should be small,thin and controlled between the contacts?
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