DR650 3rd gear blowups

Discussion in 'Thumpers' started by NordieBoy, Jan 16, 2009.

  1. NordieBoy

    NordieBoy Armature speller

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    Compiling a list for posterity and interest...

    NordieBoy 2001 60,000km
    Transalper 2001 55,000km
    Rosscoact 2004 13,000km
    Mardy 1997 53,000km
    TH 1999 40,000km
    RubberCow80 2001 25,000km (2nd gear?)
    #1
    11motos likes this.
  2. ADVJake

    ADVJake ***** dweller

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    good on you mate
    maybe something to submit to Suzuki. the DR is long due for an update...

    13,000kms is nothing, im surprised he still owns a Suzuki :D
    #2
  3. Aussie Trev

    Aussie Trev aka DRTrev

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    Are there any tell tales noises or shifting abnormalities beforehand? Or is it just 'BANG'? :huh
    #3
  4. Max Kool

    Max Kool Xtankteam™

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    Are these prone to failure? Hmmm. I've had two of them (both 1996). Sold the first with 10.000 miles on it, and the second with 30.000. Both were problemless.
    #4
  5. Dirtgrain

    Dirtgrain Been here awhile

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    What damage to the motor occurred in those scenarios? Or is it the transmission that got destroyed? Why do you think third gear is significant?

    To be more objective, maybe tally blowups that occurred in other gears, as well.
    #5
  6. Foot dragger

    Foot dragger singletracker

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    Honda XR 600s have blown third when run hard since their inception,I dont think Honda ever address'd it. 4 DRs out of how many out there? hard to call it a trend but maybe more will chime in.
    #6
  7. NordieBoy

    NordieBoy Armature speller

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    DR650 3rd gear blowups...

    NordieBoy (NZ) 2001 60,000km
    Transalper (NZ) 2001 55,000km
    Rosscoact (AU) 2004 13,000km
    Mardy (US?) 1997 53,000km
    TH (NZ) 1999 40,000km
    RubberCow80 (AU) 2001 25,000km (2nd gear?)
    Philth (AU) 3 bikes <20,000km (2nd gear?)
    BikeRooter (AU) 2006 10,200km

    I'd probably put the 2nd gear ones as Aussies tanked up on fourecks being confused about this "counting" thing.

    I'm starting to think it's 3rd gear itself. The design of it with the thickness of the metal and the selector grooves and the more you use 3rd gear under load. All the low mileage ones are Aussie with quite possibly heavy 3rd gear sand use.
    #7
  8. NordieBoy

    NordieBoy Armature speller

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    Low revs going up a slight hill and it was a drawn out cruuuuuunnnnch. I thought the chain had come off to start with.

    No warning at all.
    #8
  9. NordieBoy

    NordieBoy Armature speller

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    Looks like the engine gets totally destroyed - gears/cases/bottom end/conrod/piston...

    3rd gear is right in line with the big end.

    I think it's the shape of 3rd gear. Where the dogs are in relation to the teeth and the selector groove weakening it as well.
    #9
  10. AWM

    AWM Beard Bros Racing

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    Man that sucks!!!:cry

    Are ya gonna rebuild it??Or shitcan it?
    #10
  11. AWM

    AWM Beard Bros Racing

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    I think its proof that Ausies hate thrid gear!:rofl
    They must just put it in thrid and stay there,damn guys up shift.:lol3 :lol3 :lol3
    #11
  12. AWM

    AWM Beard Bros Racing

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    Hunh!!
    I guess i was too quick to bust balls.:rofl
    #12
  13. NordieBoy

    NordieBoy Armature speller

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    Anyone who had a blowup...
    Did one of the selector forks have both arms broken off?

    Just wondering 'cause if they broke whilst in 2nd gear 3rd may have tried to mesh at the same time...
    #13
  14. snpl

    snpl n00b

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    I have a '96 model with 135.000km on it. 2nd gear was moving to neutral as rpm's got higher.Shifting lever was also vibrating between 2nd and neutral.I dont know if my gear problem has something to do with yours but since i disassembled the engine to find what is wrong I will post below what i have found.
    #14
  15. snpl

    snpl n00b

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    Below you can see the half part of the right (as we ride the bike) of the crankcase. Be aware that the driveshaft and the countershaft are actually alligned so the 2nd drive gear and the 2nd Driven gear are in contact. In the picture this is not happening because when I split the crankcase , countershaft moved so in picture is a bit higher from its original position.

    [​IMG]

    I will try and explain a bit how the transmition between Neutral and 2nd works:

    2nd Drive gear rotates as it is attached and "locked" to the countershaft.But the 2nd Driven gear is actually rotating freely on drive shaft (Neutral Position).It needs 4th driven gear to rise up,bind with it and force drive shaft to rotate (2nd Gear Position). This happens because the 4th driven gear is bind to drive shaft in a way that they rotate together but the gear can move up-down.

    [​IMG]

    4th driven gear is moving up and down because the 1st fork embraces it and forces it to move like this.The fork its self is forced by the gear shifting cam rotation. The fork has an cylinder arm that it is attached to the cam's guidlines.Guidelines look like this

    /\
    ------/ \-------\
    \------


    (sorry for diagram but i have no clear picture for it)


    As the cam is rotating it forces the arm (and so the fork ) to move up or down to certain positions. The arrows on the pictures indicate the position of 1st and 2nd shifting fork as cam rotates to 1st, Neutral and snd gear.


    The Problem:

    When I eventually opened the crankcase I believed that the damage would be something obvious.Possible broken teeth of gears, forks, or other parts.The real problem was that everything looked ok (with no excesive damage but all parts had minor surface - contact - damage). I made a conclusion that all this small problems were added together and formed the automatic gear shifting problem.

    What is happening:

    As 2nd driven gear and 4th driven gear come close, the damaged contact surfaces cannot hold the torque provided so the gears detach (To see exactly how these gears work please consult a online part store or wait for me to post a picture!).The detachment pushes the 4th gear down so the fork is forced to move also.Eventually the fork's arm presses the cam guidline and the cam rotates to neutral.

    If you look carefully on the picture you will see that the 2nd gear position is in a guidline that forms "a top of a hill" on that spot.So it is easy for the arm to rollback to neutral position.

    I hope you can understand what is happening.Plz forgive my expression mistakes but mechanical terminology in english is something completely new to me.<!-- / message -->
    #15
  16. NordieBoy

    NordieBoy Armature speller

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    Got another one...

    DR650 3rd gear blowups...

    NordieBoy (NZ) 2001 60,000km
    Transalper (NZ) 2001 55,000km
    Rosscoact (AU) 2004 13,000km
    Mardy (US?) 1997 53,000km
    TH (NZ) 1999 40,000km
    RubberCow80 (AU) 2001 25,000km (2nd gear?)
    Philth (AU) 3 bikes <20,000km (2nd gear?)
    BikeRooter (AU) 2006 10,200km
    Madsdad (US) 2005 16,000km
    #16
  17. NordieBoy

    NordieBoy Armature speller

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    Got the quote to fix mine...

    $7300nz

    That's about $4000us...

    Just for parts.
    $2000nz for the cases alone.

    + time...
    #17
  18. ADVJake

    ADVJake ***** dweller

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    yep, when it grenades like that, its a case of, sell the rest as parts or keep as spares... buy another 2nd handy or a brand newie.
    They are cheap enough anyways :D
    #18
  19. NordieBoy

    NordieBoy Armature speller

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    Got a 28,000km 1997 for just under $4000nz ($2200us) and will transplant the engine to my rolling chassis and keep the wheels and sell the rest for parts.
    #19
  20. NordieBoy

    NordieBoy Armature speller

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    After riding a mates (TH in the list) DR650 that has blown up and been repaired it seems like I was definitely in 2nd gear when it let go.

    Also his bike has a pronounced engine based vibration from about 60kph in 3rd gear (5000 odd rpm?). I think the counterbalancer is out a tooth or 2.
    #20