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ZX9 starter motor issues - any ideas?

Discussion in 'Technical and Troubleshooting Torque' started by Loz, Mar 7, 2008.

  1. History: The ZX9 has been getting harder to start, particularly as the fuel level drops. Occasionally, even after a fill-up, it needs a push start - and that's mostly on hot days. I put it down to vapourlock or possibly fouled plugs, which are about due for a replacement.

    Now: As of last night, pressing the starter button does bugger-all except sometimes make a fast clicking noise from somewhere toward the rear of the bike (a relay?) Bike starts easily if roll-started.

    Any ideas what to start looking at with this problem? Push starting massive old litrebikes is excellent exercise but it's beginning to impact upon personal dignity. :)

  2. Could your battery be on the way out?
  3. I don't know how old your battery is. If you want to call by, I will check it out. I am only a push away.
  4. sounds like a serious case of VD.

    voltage drop :p
    bung battery, shitty connection, sticky starter relay, sticking starter solenoid, fuked starter motor.
    check 'em in that order :)
  5. or trade it on a blackbird :rofl: :rofl: :bolt:
  6. ..or more if he stalls it.. :p
  7. Yup, Joel is spot on. Your battery is shagged and now lacking the CCA's required to turn the bike over.

    Time for more start juice :)

  8. Maaate - why didn't we do a rebuild on wensdy night??

    Is the starter motor not turning the engine over quickly? Does it eventually just stop leaving you to push start it?

    If so, that and the clicking suggest that you either have:

    1) A bad battery which is not holding charge.

    You have removed it to check that the electrolyte level is up to the marK?

    2) A bad rectifier/regulator which is just not charging the battery properly.

    Good battery shops will do a quick check for you on the spot...

    The alternative is to push start it one more time and check the charging voltage with a multimeter.

    The next is to check the battery voltage while it is being started.

    Keep pushing and maybe you, too, could achieve the netrider rollover push start as sometimes described in here. ;-)


    Trevor G
  9. I've already got the netrider rollover... More of a spillover actually...


    I think Roger, Joel and Vic have got it. Starter button was doing nothing at all, and even when I push started it and rode it for a while, then stopped it on idle and hit the starter button the engine would die. That was a real gas in peak hour traffic, lemme tell ya, particularly since I'd just split to the front. These porky little legs never ran so fast trying to beat the cars away from the green!

    Got it home, and Andy had a squiz at it with a multimeter - battery's rooted alright. Tried it with another spare battery and it started immediately. It was charging at 15v on idle, which is juuuust outside the service manual's recommended range of 14.2-14.8v - but perhaps that can be accounted for by the spare battery being a bit tired. It's been sitting in the VFR400 tracky for a while and rarely being run.

    So I figure I'll get a new battery tomorrow, charge it up and see what voltage that's charging at. But yeah, should be a quick easy fix. It's almost a pity, push starting a big ol' truck like the Minja is actually pretty good fun...

    ...It sure got me a laugh as I was leaving Friday coffee! :p
  10. If your battery is much below 12.6 volts standing for a few hours after a good run in the bike or a full charge, it is down on capacity.

    12v out of a nominally 12v battery = flat or stuffed, and if it's been stored not fully charged for a while, you can pretty much bank on it being well on the way to stuffed.
  11. Loz, 15 volts at idle is too high. Did you have the lights on? Kawas have a high charge rate, but that is a lot. Your battery will dry out quick. A good trick is to put a 100w globe in the headlight, to use some more elecadatrice. It is also a good idea to put a thin piece of high density foam under the battery, to minimise the vibes, which the battery doesn't like.
  12. Dude.... you're hosting the Wednesday spanner nights... yet you dont know when your battery's flat :? :p

    Good to see you've pin pointed the problem.
  13. It was running fine on Wednesday! Shat itself Thursday morning.

    Roger, I've got a new battery and a charger, I'll get that battery charged and stick it in the bike and take another reading at idle.
  14. Righto Mate. Tell me what you see.
  15. And nothing is ever stuffed until it is!

    I normally get a pretty good run on batteries in terms of long life, but when they cave in they do it fast.
  16. I think your problem is obvious Loz, ya need a cheap 99 model Bandit :wink:
  17. Loz,

    I reckon that is a starter relay. I think the starter relay uses a small amount of current to allow a large amount of current or voltage or smurfs to flow to the starter motor. Someone with better electrical knowledge may be able to explain it better, but sometimes the relay can stick and make that clicking sound. This was the exact same case with the aprilia. You can pull the seat off and start it with your ear close to it and really hear it. Some starter motors have the relay built into them as well.

    There is also a way to test them with a multimeter, but I had no luck with that and just arsed it for a japanese version and bingo, she started better than ever.

    I would also check the charging voltage with a multimeter like Trevor G said to confirm whether it is the rectifier/regulator. Joels testing order is not a bad suggestion either.

    Good luck and may the Smurfs, volts or ampheres be with you...
  18. Cheers mate

    New battery's in and it's starting instantly.

    It's charging at 15-15.5 volts though (the book says 14.8 max), which will probably cook the new battery into a slow demise over the next few months if left as it is.

    I'll run it like this tomorrow at the Island, and then look at the regulator, which is apparently the first thing to point the finger at if it's overcharging.