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Crank Grinding

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by WiErD, Jan 10, 2006.

  1. well it looks like ive spun a bearing on the big end and need a replacement rod and crank :(

    ive been looking at getting replacement rod and crank but someone mentioned that you can get them built up and ground back to spec.

    does anyone know anyone that does this relatively cheaply or is it better just to get a second handy crank and rod.

    some places that would do this would be good also :)
  2. Think id be looking for a s/h motor from the wreckers if i had that drama
  3. it's a common practice in cars, and also quite common thing to do (word of mouth) in larger bikes (could be wrong) another thing to think about is that if it's stuffed the crank what other issues does the motor have. Maybe something to think about.

  4. and then 500 k's down the road have the same thing happen

    id rather rebuild it so i know what ive got, rather than what some guy says ive got.
  5. Yes true .. but your embarking on a big buck adventure ............. its near a 10 y/o m/cycle .... if your planning on keeping it for quite awhile go for it ....... but if your not ... may be better putting the reddies toward something new
  6. A bike from a wrecker might have a suspect motor, but most of the ones I've seen at wreckers have very low mileage and have been crashed soon after new...

    Just a thought.....
  7. yeh i was thinking that too before i pulled it all down, but ive only had it for 3 months if that, so i better keep it for a while :)
  8. If you got on top of the failure early enough the damage might not be too deep for a grind and oversize bearing, the rod big end can be resized if it ain't too bad. Only question may be heat damage and how deep that goes below the surface.

    I believe the rebuilding process is similar to the hard chroming of things like shock/fork shafts but it can't be cheap.
  9. Its a just a 4 stroke bottom end. Providing the crank and rod and block are still ok, then why not have it machine and throw it back together, check the bore size and get some rings and you have yourself a reco motor that will last for a long time...or, 2nd hand wreckers motor and trade it in. :)
  10. Metal spraying of cranks is not cheap at all expect a bill of around 600-800 biggies for grinding, spraying, straightening,re grinding etc

    Then a possible rod resizing of around 50-80 bucks

    Then youre up for a full set of bearings, gaskets, pistons rings etc to bring it back to spec or where you want to take it. ( Note insert quote price here)

    Forged pistons , carillo rods, titanium valves etc underget gears etc are all up to you and how far you want to go. ( Note insert quote price here)

    all this is based on you doing the spanner wirling etc if not allow approx 20-30 hours spanner time at mecanics or a rebuild ie measuring journals etc ( Note insert quote price here)

    OR Throw in a biggy GSXR 1100 donk from wreckers a good one. will need some time to sort bits out say 20-30 hours and 500 biggies for spacers frame mods etc and then have something to be proud of.

    Bottom line is what can you afford to do ??

    What do you want to do ??

    Just my thoughts on your problem note it cost me 1400 for a crank rebuild on a roller bearing crank set for a laverda Jota with me doing all the work ie press work and rebuild but i do not care its my bike and money has never been a issue i will be dead before it gets sold