BMW G650X Challenge Thread Index

Discussion in 'Thumpers' started by GB, Apr 24, 2008.

  1. 84ceejay

    84ceejay Adventurer Supporter

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    I like the way you think cpallen. Trying to figure out which way to go on the sprocket, any suggestions? The one that was on there was a 14 tooth.
  2. Dutchgit

    Dutchgit Completely clogless

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    Looks like someone mounted the wrong sprocket. It has happened before.
    Welding one on is possible and the quickest and cheapest solution.
    You can also fit the shaft of a 650 GS (single cylinder) bike. Those can be had used on Ebay for a lot less money.
    eaglescan likes this.
  3. MJS

    MJS Long timer

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    "Looks like someone mounted the sprocket without grease. "

    Fixed
  4. 84ceejay

    84ceejay Adventurer Supporter

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    Yeah, definitely no grease at all.
  5. cpallen

    cpallen Nearly Adventurer

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    I’m going to add checking mine to my pm tasks. My bike also has an aftermarket 14 tooth sprocket on it.
  6. Sparqq

    Sparqq Been here awhile

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  7. Gravel Seeker

    Gravel Seeker Old, growing older.

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    -- WARNING --

    That's not entirely accurate;
    A new replacement now is the same across all years, but as you can see from the fische, the part you link to superseeds the old ones.
    The old ones (mine among them) have a huge ass nut on the outside of the shaft to secure the sprocket rather than the internal bolt like on the current shaft. Nothing wrong with that shaft really other than carrying the tools to remove it on the road takes alot of room (27mm I think it is).
    So before buying the first shaft/ engine you come across check which shaft it is.

    Supersedes:
    23007663805
    (09/11/2000 — 09/15/2006)

    Pics from internet
    upload_2019-11-12_9-46-46.png
  8. 84ceejay

    84ceejay Adventurer Supporter

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    Same size as the axle nuts?
  9. Sparqq

    Sparqq Been here awhile

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    Different, size 30
  10. eaglescan

    eaglescan Borrego rocks Supporter

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    If it was me, I would try and see if a new sprocket will go on the old shaft and have any grip at all. If yes , then it could be welded on, suggest tig . Next thing is to make a large washer to suit and drill about 4 holes , (start small, like 3/16 , in that around the perimeter that clear the bolt head. The sprocket may be soft enough to allow drilling , using the washer holes as a guide. I would then use roll pins to help drive the sprocket along with the weld. I will try drilling a used sprocket I have to see how soft it is.

    OK, forget the drill idea, but if the washer is thick enough, say 1/4 ", you could weld around the perimeter to the sprocket. After welding sprocket to shaft, install the washer , and tighten bolt. Now weld around the washer to sprocket and around the bolt head to the washer. Yes this means grinding weld away when removing , but could be done.
    Of course this is not for a bike that is going on long adventures.
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  11. Sparqq

    Sparqq Been here awhile

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    Welding a sprocket onto it won't be easy without melting that seal. If that happens you have to grind the sprocket of it, to replace the seal. I would go for an older (cheaper) countershaft and accept the size 30 nut and spend some winter weekends on splitting the engine.
    cyclopathic likes this.
  12. cyclopathic

    cyclopathic Long timer

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    In addition I would look around for machine shop which could do repairs either weld on and cut splines or cut shaft and weld replacement.
  13. Sparqq

    Sparqq Been here awhile

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    It seems a Chinese guy is selling them for about $175 used and $350 new:
    [​IMG]
  14. Gravel Seeker

    Gravel Seeker Old, growing older.

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    Actually, come to think of it you're correct - it is a 30mm nut. Internally the nut is an M20x1.5.
    (It's my KTM steering stem nut that is 27mm)

    upload_2019-11-13_9-45-31.png
  15. Sparqq

    Sparqq Been here awhile

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    The bolt (25) on the sprocket requires socket size 30. The axle bolts on my F650GS require socket 19 and 24 if I remember correctly, for sure it's not a size 30.
  16. Gravel Seeker

    Gravel Seeker Old, growing older.

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    I know, but this is the G650X thread and that might :lol3
    Our axles are 17mm, theirs are 24 or 26 or something fancy like that.
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  17. OzAnt

    OzAnt Still searching

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    Ok been there and done that with the striped counter shaft sprocket.
    You start by sticking the bike in a crane and removing the back wheel and move forward until you are left with the front frame member and front end intact. I was luck to get hold of a hospital patient crane to work on my bike, worked really well.
    The motor is relatively easy to do with the manual and a few you tube videos.
    Have lots of part trays and zip lock bags and tape to mark up all the fittings, connection and parts for reassembly
    Get the parts before hand with new seal kits and water pump kit while you are in there. I end up using OEM parts as I got trade prices for the parts.
    Set aside 1 day to get the motor out, 1 day to strip motor, 1 day to assemble motor and 1 day to install motor, you can do it quicker but then you risk dong something wrong.
    My bolt would not come out, end up using a 3/4" drive rattle gun and that moved it. Problem is some people use the nut torque on the bolt instead of the bolt torque which is about 1/3 of the nut so it makes it really hard to get the bolt out. You can stick in the crank lock bolt to help hold the motor to undo the bolt on the counter shaft. You can make these yourself, some post on ADV ride about doing the motor show you how.
    It is not that hard a job if you prepare yourself well for the task.
    Some good write ups on ADV rider to do the work as well.
    https://advrider.com/f/threads/ocr-...ck-august-13-14.1082462/page-42#post-30765053
    Some pics of mine and a few words.
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  18. Gravel Seeker

    Gravel Seeker Old, growing older.

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    Not sure exactly which bolt you mean since you don't specify, but (general) you might try to loosen the bolt at the very beginning when you still have the wheel on. Depress brake to lock rear wheel = "lock" engine. Once it's loose continue with your steps.
  19. cpallen

    cpallen Nearly Adventurer

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    He is talking about the fastener on the end of the countershaft that secures the sprocket. In early models, apparently it is a big 30mm nut on external threads and in later models a bolt in a threaded hole,
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  20. eaglescan

    eaglescan Borrego rocks Supporter

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    And it is a RIGHT HAND thread ( normal) , I just pulled my sprocket and greased. I guess the grease is to prevent rusting, which would cause more wear?