HELP!! F**KED my LC4 cam

Discussion in 'Thumpers' started by Dotbond, Nov 19, 2007.

  1. bmwktmbill

    bmwktmbill Traveler

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    DB,
    i never heard of a a KTM impeller failing but I replaced mine anyway. I would agree that #5 is the seal.

    I have heard of impeller failures with the Kaws and the BMW singles,
    FWIW. when I replaced mine but I wanted a spare.
    b.
    #21
  2. gunnerbuck

    gunnerbuck Island Hopper

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    Your waterpump seal should still be OK with only 15,500 KM on the bike. I redid mine at 40,000 and the old one showed no signs of weepage. The shaft did have a small groove worn in it from the lip of the seals rubbing but this was minor.....But like my follower bearings I rebuilt the pump anyways to play it safe {plus if you pull it apart you might as well rebuild it}.
    #22
  3. Dotbond

    Dotbond Africa, Africa

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    Any opinions on the debris on the drain plug??
    #23
  4. holycaveman

    holycaveman Long timer

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    Your oil filter and screen should take care of any excess shavings. Once you get it back together, change the oil and filter again soon. You should be fine.
    #24
  5. halfcab

    halfcab Been here awhile

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    I suggest you tear the motor down and clean out. Plus flush the "complete" oil system, oil lines, don't forget the frame.

    All it would take is one small object hiding for a while to make it's way to a roller bearing.
    #25
  6. gunnerbuck

    gunnerbuck Island Hopper

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    When I had my top end failure I did a complete teardown,flush and replaced the crank bearings. But I had larger debris chunks in the oil {piston ring pieces} and they did damage 1 crank inner bearing race. But the path they took to get to the sump was right thru the unprotected {unsealed} side of the crank bearings as well as the conrod bearings. In your case the oils path will take it down the cam chain canal to get to the base where the screen and magnets hopefully pick up any large chunks from the oil before going thru the pumps.

    All other bearings in my engine were in good shape other than the 1 crank bearing...

    Chances are that you will get away with just a few flushes and things will be fine but as Halfcab suggests all it takes is 1 little chunk to ruin your day.
    #26
  7. Dotbond

    Dotbond Africa, Africa

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    I see some weird looking tools are required to strip the motor, as in a clutch basket holding tool. Are there alternative things that can be used?

    1. So what special tools do i need if i were to strip the motor myself?

    2. How 'stripped' would the motor need to get?

    3. Also what gaskets and seals(if any) would be required?
    #27
  8. bmwktmbill

    bmwktmbill Traveler

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    DB,
    You can always rebuild the motor if you have a problem...if you have a problem, if you get my drift.
    In this life I think I replaced more good parts than bad ones.
    b.
    #28
  9. gunnerbuck

    gunnerbuck Island Hopper

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    #1 The only special tool that I needed to do the complete teardown was a flywheel puller and instead of buying one I rented one for $5. I used an electric impact wrench to take off the clutch and crank end nuts so very little holding effort was required... You will need some bigger sockets to fit some of the nuts and a good torque wrench for reassembling {125 lbs torque required on the primary}. A second 1/4" torque wrench is handy for the low torque applications and will see the most use. For reassembly you will need to come up with a way to hold the crankshaft while torqueing the end nuts. I made up a couple of blocks that straddled the case and used the piston pin onto the blocks to hold her steady. If you have a good air wrench and trust the psi setting you could use it to torque the bolts and not have to hold as much force. For tightening the clutch hub I made up a holding tool out of a piece of 520 chain and used the countershaft sprocket chained to a dowel sticking out of the rear engine mounthole with the tranny in gear to hold things.

    #2 I would say you would probably be able to flush things out pretty good by splitting the cases but leaving the gearbox in place. I use varsol, a small pump and a catch tank that recycles the solvent to flush engines. You can tilt the engine and shove the hose into the nooks and crannies and flush the debris out. Take the oil pumps apart and check them plus blow air and solvent thru oil passage ways.

    #3 If your carefull you can reuse some of the casegaskets but I would have a spare for everyone. Don't try to reuse the centercase gasket as this is one that has to be replaced. You'll need a headgasket {expensive}, a basegasket, a new seal ring for the camchainguide bolt, Hondabond HT for the rocker cover, loctite blue. Should also replace a few O-rings mainly the one inside the countershaft bushing and on the starter and starter gear cover. Also I would also recommend replacing the 2 studs and nuts at the front and back of the cylinder head as these always seem to get a bit crusty. Also inspect your engine mounting bolts {mainly the long ones} for signs of fatigue (pitting and crustiness} and replace if they look bad...


    This is a pretty big undertaking that you may not feel comfortable doing. If this is the case I would suggest that you pull the engine out and take it apart as far as the top end removal and then take it to the shop for them to split,flush and reassemble the bottom end...You will save big time on labour costs....Or just replace the cam+ followers and flush the oil a few times and call it good...

    Good luck with whatever way you choose to go....
    David...
    #29
  10. Dotbond

    Dotbond Africa, Africa

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    bmwktmbill and gunnerbuck, thank you for your input. Much appreciated.
    I will be making a decision on Sunday after seeing a retired mechanic friend. Need to order parts soon before xmas arrives otherwise i will be stuffed for a 5 day ride at the end of January 08.

    Will keep you posted.
    #30
  11. bmwktmbill

    bmwktmbill Traveler

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    DB,
    The seal on the end of the crank that is mounted in the clutch case should be replaced no matter what if you have that case off for inspection. If it fails, no oil pressure to the crank and then you will rebuild your engine for sure.
    Easy to over look this one. I did and had to tear ir apart again for peace of mind.
    b.
    #31
  12. Dotbond

    Dotbond Africa, Africa

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    Update time. Got new cam and bearings and seals and numerous other bits and pieces. I have tipped a couple of engine fulls of oil thru the motor and let it drain out. No metal in the last drain. Took the clutch cover off and pulled out the clutch plates as well. No metal there either. I poked my magnetic tipped pointy thing in all the holes i could find but only got some metal in the "oil bath" that is right under the cam on top of the head.
    I got the bike shop to change the inlet cam follower bearing, the shaft was knackered completely as you can see below, but did the exhaust bearing myself.
    [​IMG]
    Pictures of how i did it to follow.
    [​IMG]

    I drilled one end of the bearing shaft around where the press mark was that spread out the end to stop it from moving. This was to relieve some pressure according to my theory.
    [​IMG]
    I got a socket with an end smaller in diameter than the shaft and another socket wider than the shaft and put them in a
    vice and pressed the shaft out as per the dodgey photo below. The new shaft and bearing just slide into position and i went round both ends of the shaft with a dot punch to secure the shaft in place. Sorry no photos of that last bit.

    [​IMG]
    Also replaced the water pump seal and bearings, not that they needed changing as there was not any wear on the shaft. Assembled it all last night and now waiting for the rocker cover sealant to cure for a day or 3.
    Will fire the bike up on Friday hopefully and do some hot oil changes.
    #32
  13. gunnerbuck

    gunnerbuck Island Hopper

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    Thanks for the update.. I'll say that shaft is toast....

    Hopefully that'll be the end of your problems...

    Good Luck...
    #33
  14. bmwktmbill

    bmwktmbill Traveler

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    DB,
    Neat trick to push the shaft out.
    Good luck,
    b
    #34
  15. Dotbond

    Dotbond Africa, Africa

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    And another update.
    Got the bike all assembled with fresh oil and filters and have ridden the bike for about 1 hour. I then drained the oil out of the motor only via the 2 drain bolts, didn't worry about the downtube. There was some fine metal on the screened drainplug and the actually magnetic parts as well but sod all. And about 3 flecks of metal in the oil itself. Have put fresh oil into it ready for another ride where I will do the same again.

    Merry Xmas.
    #35
  16. gunnerbuck

    gunnerbuck Island Hopper

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    Sounds good D.B. and Merry Christmas to you...

    David...
    #36
  17. bmwktmbill

    bmwktmbill Traveler

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    DB,
    Thaks for the updates.
    Nice job.
    b.
    #37
  18. Dotbond

    Dotbond Africa, Africa

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    And another update. The bike has done over 2000km since the new cam and bearings. I have just pulled the rocker cover off and inspected the new bits. All is well with the repair. :D
    #38
  19. braaap!

    braaap! Long timer Supporter

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    bingo Dotbond!

    [​IMG]

    same happened to my top end at about 30000kms... after a dealer service!

    Full rebuild followed at their expense as the bike was still just within warranty... and the fact that I'd heard on the grapevine, that the mechanic 'had trouble' setting the clearances at the last service ...

    Rebuild took 4 months though!

    :huh

    I think this damage begins to happens if the oil change 'burb' is forgotten.... or there was a batch of crap bearing / bushes.... or... shit happens.

    I'm at 40000kms with no probs.

    Good luck with yours
    #39
  20. Dotbond

    Dotbond Africa, Africa

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    braap: Looks familiar! Lucky your bike was still under warranty. Good luck with yours as well. I sometimes wonder if it occured because i was running slightly heavier oil 15W40 instead of a 10W50. Who would know!
    #40