KLR650 Engine Rebuild Photos and Questions!

Discussion in 'Thumpers' started by rectangular, Jan 8, 2013.

  1. larryboy

    larryboy Chopper Rider

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    On a set of 50,000 mile tires.

    Yeah, factory. Brand new bikes can look like that. It's cheap to take a look and can be really expensive to ignore.
    #41
  2. gravelklr

    gravelklr gravelklr

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    :popcorn:

    Signed up for this....thanks for sharing.
    :sun:
    #42
  3. DirtyDog

    DirtyDog Lust for dust.

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    Ok. I think I have a good theory on the demise of this topend.

    1. From your pictures, the right side cam caps were BOTH installed backwards. In motor assembly, indicator arrows always point to the front of the engine.
    2. Because the head, cam, and cam caps are all "machined together", flipping them around could likely change the fitment. I'm guessing this was done at a valve shim swap by the PO. You didn't list the valve shim specs as you found them, did you?
    3. If the cam caps were installed backwards (with a poor fit), torqued to spec, and later discovered "worn" as you see them, then the tight/poor fit could be partly to blame for the poor lubrication which compounded the issue. Once they scored, the torque spec probably went into the crapper and they were later discovered "finger tight".
    4. This above combined with low oil pressure caused by a) a leaky oil banjo bolt, b) a poorly fitting K&N oil filter (which wasn't likely filtering the shavings adequately), c) a severely clogged oil screen, and d) possibly the PO under-filled with oil.

    Sound plausible?

    Great write-up.

    And a tip-
    Don't bother trying to re-install that water pump shaft seal. Buy a fresh pair.
    Also, I've noticed these K&N oil filters don't fit worth a damn. Go with the Hi-Flo variety instead.
    #43
  4. newcastleadam

    newcastleadam Artful Tagger

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    Ditto on the good write up and pics. Couple of tips, things to consider, etc:
    • the water pump impeller has an O-ring in there, it's much easier to screw it on and off the pump shaft
    • Take a good look at the oil seal on the inside of the clutch cover, it can get nicked and it's much easier to deal with now

    Best!
    #44
  5. rectangular

    rectangular Adventurer

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    Great suggestions! I noticed the arrows on the cam caps didn't seem to be pointing the right direction when I was taking it apart. I wasn't sure at what point they were set that way. I remember the PO mentioning that he had someone look at what was making the noise. Not sure if it was them, or another previous mechanic/owner.

    I didn't notice that the K&N filter didn't have the best fit. I'll try and find one of Hi-Flo filters that you have mentioned.


    Good points! I'll make sure to mark those down on my todo list.
    #45
  6. Nanuq

    Nanuq Aventurer by Trade

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    Thank you so much for the write-up. I am an extremely visual person and this definitely helps out a lot for somebody that thinks like I do. :D


    I've torn into my bike several times on the upper end and on the sides, but never down to the cylinder jug. Now I know how to do it.

    It might be time for the 688 kit, I'm curious if you were swayed by either 688 or the 685 kit more?
    #46
  7. rectangular

    rectangular Adventurer

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    The 685 kit is probably the better route to go in the long run. The 688 kit is really only made to be used when your 685 wears out. Unfortunately the 685 kit is backordered temporarily and I'm kind of impatient to get this bike running again. :) Plus, the 688 kit was $5 cheaper. Gotta stick to my budget! :D

    I chatted with Eagle Mike on the phone briefly, and he said the 685 kit is getting a new stronger piston material, which is why it's currently out of stock.

    People might have different thoughts on this, but that was my decision process.
    #47
  8. Dan in Grand Rapids

    Dan in Grand Rapids Adventurer

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    This thread is awesome, and you are doing exactly what I want to do to my KLR. I do have a question though. What did you you do with the chain when you took the jug off? I can't see the chain, and wonder what you are supposed to do with it. I have taken heads off of cars and was always worried that it would slip off the sprocket on the crank and the timing would get messed up. I look forward to more pics and details.
    #48
  9. newcastleadam

    newcastleadam Artful Tagger

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    I believe it is ziptied to the frame. A good thing about the KLR cam chain is that it can't slip off the bottom gears due to the chain guides. Of course having said that....:D
    #49
  10. securety10

    securety10 Stuck...

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    May be in a similar scenario here pretty quick. Found an 08 that was run low on oil and destroyed the exhaust cam journal. I don't mind the top end is shot as the bike would be for my dad for our intended TAT trip this summer. I intended to do the 685 and headwork on any bike he got for improved reliability and better freeway cruising speeds when needed. It would be nice to save money on a bike that needs some of the work i planned to do. The only real issue is trying to determine if the bottom end sustained damage in the low oil state.
    #50
  11. Old Kiwi#99

    Old Kiwi#99 Been here awhile

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    Bottom end of the KLR is all roller bearing like a two stroke, so it will survive low oil flow & low pressure for longer, where plain bearings (ie cam journals) will die
    #51
  12. CA Stu

    CA Stu Steer with your face! Super Moderator

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    Cam chain tensioner removal;

    I would have done that differently.

    You have to take the center bolt out first. What you have done now is to leave a spring pushing on the tensioner even though there is nothing for it to tension (the other end of it should be applying tension to the chain).

    The cam chain tensioner is now at the limit of its travel and now you need to remove the spring, reset the sliding part to fully closed, reinstall that part, then put the spring back in, and THEN put the center bolt in.

    This all needs to happen AFTER you have put the cams back in the head. :D

    Edit:
    [​IMG]
    BTDT.
    Loaned the bike to a guy who ran it low on oil. Oops!
    #52
  13. newcastleadam

    newcastleadam Artful Tagger

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    Had that happen to my first project KLR. Crank bearings failed, top end was fine. Still not sure how the PO did that.
    #53
  14. CA Stu

    CA Stu Steer with your face! Super Moderator

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    Give that man a cigar!

    Also, a shot or two of compressed air to the spark plug area before taking everything in there apart is a good idea. It will clean out Timmy and his friends.
    That area always fills up with small rocks, bugs, and crap.
    #54
  15. securety10

    securety10 Stuck...

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    That is the main thing on the bottom end I am worried about, but cranks in good working condition seem to go for rather reasonable prices on ebay. Splitting the cases isn't that horrible, but I'd prefer to not have to do it.
    #55
  16. Kevan Garrett

    Kevan Garrett Been here awhile

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    Hey Rectangular.

    Great build, thanks for the pics and info. Please keep up the good work. I have done the doohickey and the $.22 fix for the carb on my KLR's. I am not a particularly good wrench, but I would recommend that you take a look at the carb while you have everything off. Just generally checking of the float bowl and the diaphragm. And the $.22 fix (which cost me $.47, inflation) is really simple, though maybe unnecessary at higher altitudes.

    Keep up the good work and thanks again. I am subscribed. :clap

    Cheers

    Kevan
    #56
  17. rectangular

    rectangular Adventurer

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    Thanks! Glad everyone is enjoying this.

    I'm not sure I'm familiar with the $.22 fix for the carb. Can someone enlighten me? :D


    Update: I got all of the parts in from Eagle Mike except for the refreshed head. Damn, that 688 piston looks good. Next step is to drop the cylinder jug off at the machine shop and get it bored and honed.
    #57
  18. Kevan Garrett

    Kevan Garrett Been here awhile

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    #58
  19. rectangular

    rectangular Adventurer

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    Quick question for anyone who has been following my thread: what oil would anyone recommend for my engine break in? I've used rotella 30W for car engines, but I'm unsure about motorcycles. I'm not looking to start a flame war, just asking for some suggestions :)
    #59
  20. rectangular

    rectangular Adventurer

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    Well... ran into a bit of a snag today. I got the cylinder back from the machine shop, got the new piston and cylinder installed. I also got the new doohickey installed as well with the torsion spring. Unfortunately when I was torquing down the rotor bolt for the stator and starter gear, the cam chain got lodged between the block and the large starter gear. :huh

    It looks like as I was torquing down the rotor, the chain got slack and pinched between the block and the rotor.

    It broke off a bit of the block. It looks like it's only purpose is to hold the front cam chain guide. It didn't chip off terribly deep and it still holds the cam chain guide.

    [​IMG]

    [​IMG]

    [​IMG]

    :eek1

    There was also some marking on the back of the rotor and it bent the sort of toothed bit on the back of the rotor.

    [​IMG]

    I'm curious what everyone thinks the best course of action is to do at this point. A bit of a bummer after a solid day of successful wrenching prior.

    I don't really think replacing the block is much of an option. Nor do I think it's all that necessary. To buy a new starter rotor from the dealer is $238. On ebay they go for around $70. I'm not sure what this bit on the back of the starter rotor gear is for. Kawasaki put it there for a reason. Is this something that can be flattened, smoothed down and reused?

    The cam chain seems to be unscathed. The cast aluminum block definitely lost the battle between these items.
    #60