790 Reported Clutch failures - My 12k mile examination

Discussion in 'Parallel World (790/890)' started by windblown101, Nov 10, 2019.

  1. braaap!

    braaap! Long timer Supporter

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    Slurp, number drills!

    Well mine aint going to cut it :photog

    drills.jpg

    I might have to put in an order after your test results.

    :deal
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  2. 1coolbanana

    1coolbanana Long timer

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  3. braaap!

    braaap! Long timer Supporter

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  4. coloktmGS

    coloktmGS Been here awhile

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    Any chance that opening this hole and increasing flow decreases oil pressure somewhere else in motor and causes a more significant/predictable failure?
  5. 1coolbanana

    1coolbanana Long timer

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    No, not really, the oil pump pumps a large volume while maintaining a regulated pressure.
    As flow increases due to pressure variation, it is regulated, like when it gets hot and the oil pressure would drop from the lower viscosity if not regulated.
    The size of a jet is so miniscule in the overall flow that opening it from 0.07 mm² to 0.2 mm² is meaningless in the overall flow and pressure in the system.
    If you left the jet out altogether thats a different story
    Hope that makes sense
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  6. chain

    chain Go Fly Supporter

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    1600 miles of Baja. Clutch is working without issue. Turned north this morning. More news at 11
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  7. Toddv

    Toddv Long timer

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    I pulled my cover yesterday to inspect with 800 miles, Everything looked new. I pulled the oil jet and it was perfectly clean but that's a tiny hole, a grain of sand could plug it. I wouldn't expect it to clog if it hasn't by now as any manufacturing crud/debris should have worked it's way through and barring a failure of some sort everything coming through the oil pump should be first filtered by the pickup screens and oil filter. I think I'll drill it to .4 mm once I find the proper bit just to get a little more oil in there, approximately double as noted.

    Also, I tried my Camel clutch lever in the third position but wasn't comfortable with the amount of freeplay I had to run as to not have it drag while pulled with a little margin for error so I moved it back to the center position. I'm probably just being overly careful here but I'd rather not worry about it. I always check freeplay at the lever on the clutch cover, at the cable can be somewhat misleading.
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  8. ramirin

    ramirin Ready to push

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    Oil jet cost around 5€ so I will buy another one to drill before opening the case. Also considering Rekluse discs.
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  9. Kinkysmurf

    Kinkysmurf Adventurer

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    I am a little surprised with the freeplay set, its giving you drag, but every clutch is a little different.

    I'm in the 3rd hole, ( to early for kinky to go there)
    Checking mine the other day I have about 2-2.5mm play at arm, which is giving 10mm + at the bars.

    I have more freeplay (2x) than what it specifies in Manual. I do get a touch of drag when its stone cold, shifting in 1st, but nothing like drag that will move the bike forward and it feels perfect when warm.

    Setting this clutch is a finer point than any other cable clutch bike Ive owned and can remember.

    IMO the KTM manual should be directing everyone to check that freeplay is evident at clutch arm/case. They assume and rightly so that freeplay of 5mm at the bars is impossible without freeplay at arm/cover end.

    Even the expansive repair manual doesnt give clear instructions, they assume you know what you doing.
  10. Toddv

    Toddv Long timer

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    Yea those aluminum disks feel scary light. Steel won't explode if it gets hot either.
  11. Toddv

    Toddv Long timer

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    It wasn't giving me drag pulled all the way in but there was very little movement before things start spinning. I guess maybe let out 10% and things start spinning in neutral. I don't want to have to pull my clutch lever all the way to the bar to find neutral and have it fully release. The middle hole is a big enough improvement over the stock friction zone and pull for me anyhow so leaving it there. I don't think it would ever cause an issue, I just don't like it that way.
  12. windblown101

    windblown101 Long timer Supporter

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    I broke down and ordered a TorqDrive. It should arrive in the next few days? I had already replaced my original clutch pack with a fresh OEM clutch pack but I keep seeing stories pop up about every other week it seems like of the aluminum plates grenading inside the motor after someone tried to nurse a bike somewhere after some slipping was noticed. If I were in the middle of no where and for whatever stupid reason my clutch started slipping with the stock clutch pack I'd be terrified to try to limp back to civilization under the bikes power, that doesn't work for me.
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  13. Kinkysmurf

    Kinkysmurf Adventurer

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    I have been on rides in horrible, sticky mud. Guys that burnt their clutches let them cool a bit. Then pull out the pack and rub the friction plates on a rock, reassembly and go home very gentle.
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  14. Camel ADV

    Camel ADV Long timer Supporter

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    I haven't noticed much (if any) change in finding neutral.
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  15. windblown101

    windblown101 Long timer Supporter

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    Exactly. Limping home with a burnt up clutch should not be a motor ending exercise, and as @gearheadE30 mentioned, the steel plates weighing a bit more may actually be a benefit at low revs. Will be interesting to see how they work out.
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  16. Thumper Dumper

    Thumper Dumper Been here awhile

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    Remember the KTM manual does not cover the longer arm you have installed.
  17. 1coolbanana

    1coolbanana Long timer

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    To be honest, the longer I wait for the one finger clutch to arrive the more Im getting used to the stock setup and finding less need for any change.
    Stock setup seems fine the more I use it.
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  18. Salzig

    Salzig Long timer

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    Thinking out loud here.
    Assuming KTM know what they do (I know, I know...), couldn't it be that the short friction zone is there to have a full pull even with a big free play?
    I mean, maybe the engineer who designed the clutch system knew this type of clucth needed a greater free play and designed the arm accordingly.
    Then that got missed when they printed the manuals.
  19. Kinkysmurf

    Kinkysmurf Adventurer

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    My memory is fine, except when the girls spike my drink.
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  20. ramirin

    ramirin Ready to push

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    Few hours ago ordered oil jet and just before sending added TorqDrive - for the same reasons you mention. And I know I'm active on clutch and slipping a lot when offroad.

    I had rekluse slipping on 690 while we were on swamp. With bike sinking all the time couldn't notice the slipping until came back to road, couldn't even do a wheelie on first gear. Adjusted the screw on autoclutch few notches, removed some fluid from reservoir and enjoyed the rest of summer. Heavy duty stuff.