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broke a nut!

Discussion in 'Technical and Troubleshooting Torque' started by MrWasabi, Jan 14, 2008.

  1. My Kawa ZZR 250 is coming along nicely, been fixing it to get it registered and all that is left to do is new sparkies and replace the gasket of the left hand magneto cover. Picked up the part on the weekend and replaced it.

    As i am tightening the nuts up again, i thought id refer to the service manual... No where would it tell me the torq which the nuts had to be tightend to, or in what order (dont know if its needed but i am going off replacing a gasket in a car engine) so i thought i would try it and see.

    I am going around, screwing them all in, sure enough one snaps...@#$^&!!!
    the gasket and the glue are doing a good job now that no oil is leaking, specially from where the nut broke, but i dont want to leave it like this.
    I am fairly confident i would be able to get the nut out but i will need a replacement one. I want to avoid going to Kawa, as they might charge me a couple of hundred dollars for a complete set of nuts, plus i dont know if they would still have parts for a 96 model bike.

    So, few questions...
    1. Should i bother replacing it? (i have run the bike for 30 minutes and it does not leak at all)
    2. Where can i get torq specs about the nuts? i cant seem to find them in the service manual
    3. Would anyone have one of these nuts laying around doing nothing that they would like to sell :)
    4. Where can i get a replacement from? yes i kept the other half of the nut.

  2. Take it to coventry fastners or nubco or equivalent. They will measure it and find a suitable replacement.

    A new nut shouldnt cost you any more than $2.50 (if that)

    Can't say ive ever snapped a nut.. sheared bolts yes but cracked nuts, no.

  3. A nut is a hexagonal sort of device with the threads inside it. I have never seen a broken one, although you can strip the threads out from inside it. A nut is referred to as a female device (because the bolt goes inside it.)

    A bolt, on the other hand, has a hex head and a protrusion with the threads on the outside of this. These can break off at the head, or partway along the thread, if you tighten them too much.

    You would have to give the measurements for the bolt, or take a similar one along, to be able to have one matched for you. Professional nutteries (you know, where you buy nuts and bolts) usually have a $7.50 minimum charge.

    I don't think ANY Kawasaki dealer would charge that much for the correct replacement bolt.

    You will also have to find some way to remove the broken piece if it is still stuck inside the engine case/housing.

    All the best

    Trevor G
  4. I'd say he has twisted the head of a cap screw myself.

    You may need an easy-out to get the broken shaft out.

    Most car parts places have standard cap screws on the shelf.

    As to tightening, you should be only tightening these sort of wrist tight on the allen key.

    Although some turkey put an aluminum set through mine in the past and I've broken a few with bugger all load. If that is the case with yours, try and get a Stainless steel set off ebay and replace them all.
  5. I hope the girl was satisfied, and apologised for breaking it. :LOL: :twisted:

    Oh, and visit a bike wreckers.
  6. thanks guys, yes it is a bolt, a 10mm bolt to be precise, not a nut...dont know what i was thinking there...
    been a couple of days since the incident and i checked the bike out again, sitll no leaks, i run it every day for about 15 minutes to keep it alive...as till its finished it aint moving...
    but i havent noticed any oil leaks... i was very generous with the gasket glue...now its set like a rock.

    honest opinions on leaving it as it is?
    it is only one bolt from the magneto cover, and there are 9 to hold it down...well 8 now... how oily does it get in there?

    will definatelly get myself a set of easy-outs...and further down the line replace all the bolts with some high tensile ones...
  7. If it's a dry magneto (and I have no idea what part you really mean - are you referring to the alternator?) then there will be no oil in there. Was there oil "in there" when you pulled the cover off?


    Trevor G
  8. In response to your questiion about leaving it as is, I guess it depends on where or how far you are going to go. While it is not ideal to leave it as it is if you are not going on an interstate trip I'm guessing the worst that is going to hapen is that a slow leak/drip will develope.
    How far in is the broken part of the bolt? Can you get it out with an easy out without removing the cover?
  9. That's chain oil spreading to the alternator cover (I've cleaned the whole area and watched the progression over a few rides).
  10. this is the cover i am talking about

    There was oil when i removed the cover, but i had drained it, so i dont know if this compartment fills up...

    Technically speaking no i wont be doing long trips, maybe the odd cruise here and there with some of you guys when i get this thing registered (and no the one above is not mine, so you dont have to be embarrased riding with a yellow zzr :D) and daily comute to and from work

    I guess i will eventually get myself a set of easy outs and pull the damn thing out, but in the mean time if a slow leak is the worse that could happen, i can live with that... as long as its not as catastrophic as leaving a broken gasket on a car engine then im ok with it
  11. You might be thinking of a head gasket, which can fail in a bike as well.

    However, the area you have indicated is not under high pressure and so 1 missing bolt should not be serious.

    All the best

    Trevor G