no start no spark

[andy r]

hi i am in need of some help the story so far is, i did a track day at cadwell on thursday on my zxr400 l5. i went out for the first session and the bike was miss firing at about 12000 rpm, had a look at the bike found no prob so went out for the second session bike would not start [battery had died] bumped of the bike after one lap it was now miss firing all through the rev range, when i pulled up on the bike it would not rev above 8000 rpm turn off the bike now it will not start. i have had a look at the bike and i am not getting a spark on any plug on any lead but i have no idea where to start looking any help welcome cheers andy

[Davw]

Assuming that 1) this is a road bike and 2) you have taken a plug out and tested for sparks and 3) the battery is now charged and 4) the bike turns over on the starter then this is either

1) Failed CDI - possible as the bike was misfiring before finally failing
2) Failed coil (this is a possibilty but both wouldnt fail simultaneously however it is possible that the plug you removed comes from the failed coil so try one of the plugs from the other coil)
3) Loose connection (somewhere in the circuit - check all connections properly made and no loose wires)

The misfiring and then limiting revs sounds like the CDI has gone but!! on the other hand the bike might run on two/ three cylinders but unlikley to start so it could be a coil

On a differnet subject - if the battery was flat that probably means that the regulator/ rectifier has failed (or loose wiring from the charging circuit) - check that when you get the bike running again.

[andy r]

cheers mate i have all the plugs and all the leads of and no spark on any and i have look at the wiring which looks ok so it looks like the cdi. the only other thing could it be the pick up coil and is there any way off testing it cheers andy

[Davw]

Andy - have never tested a pick up so am a bit out of my league on that. It cant be too difficult as it is an electromagnetic switch (I think) - best person to pm might be tk400 - hes a bit of an ignition guru

[RedexRobB]

Theres a test for the pickup in the manual, its simply a resistance test, whack your meter leads across the two wires and if its between the specified value its fine. If not then that could be your problem

just had a look for you and its meant to be between 355 and 535 ohms across the black lead and yellow lead

[andy r]

i am now sure it is the cdi box dose any one know which will fit? is it any of the L models except L9 cheers andy

[RedexRobB]

as far as im aware all L model CDI's are interchangable Best go for the Blue stickered 'M' CDI's as these are uk ones and dont have the speed restrictor in. Also a better CDI overall as i understand, due to a better ignition curve