what do you get if you combine and RS 125 and a 640 LC4???

Discussion in 'Some Assembly Required' started by muttley92, Mar 30, 2013.

  1. muttley92

    muttley92 Adventurer

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    So it ran properly for the first time with a complete exhaust system. and it made a horrid knocking noise.
    http://www.youtube.com/watch?v=uSKuxUwipiQ
    so I opened the top and found that the needle bearing had collapsed and caused this
    http://www.youtube.com/watch?v=aqR0PApUiHs
    Also knackered the camshaft. So much love for the T**t that sold me this engine. I've ordered a new camshaft and relevant bearings/ seals. It'll get done eventually, most likely in summer due to looming exams. This is my current state.
    [​IMG]
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    #41
  2. Donkey Hotey

    Donkey Hotey De Jo Momma

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    Dead weight is nice. That's your statics class. Have you taken dynamics? What about when that thing starts up and flexes those welds to death? The LC4 is known to be a paint shaker. I'd seriously rethink the design of that front mounting system.

    Also: the LC4 doesn't need an oil tank at all. The original engines didn't have one, nor did the strictly off-road models. The oil capacity was to add some extra oil to wear out and burn, as well as a place to mount an external oil filter. On the original design, the filter was located where the e-starter lives now.

    Have you considered something like an automotive remote filter mount and using the largest oil filter you can find? That should add 500cc of capacity and a filter without having to worry about that oil tank failing.
    #42
  3. muttley92

    muttley92 Adventurer

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    As mentioned before, I am well aware that these engines vibrate. I have done dynamics and vibrations, I'll keep an eye on it and if it cracks I'll do something different. Oil filters tend to be round. There isn't much space, the tank I've made fits nicely in the frame and there's no reason it should fail, there are several brackets on it that I just don't have photos of. But you get the just. The extra capacity won't hurt and it will lower the oil temperature. Can't be a bad thing. At the moment I'm more bothered about fixing the engine...
    #43
  4. sam_2555

    sam_2555 Adventurer

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    Ben, I had no idea you were fabbing so much up yourself! Fair play mate, you've got some skills.

    I'm pretty jealous at how well yours is turning out. Liking the black and orange colours.

    I hadn't even thought of wrapping the headers to save the rad/cooling system. Definitely going to be doing that I think.

    Keep up the good work (time permitting).
    #44
  5. clintnz

    clintnz Trans-Global Chook Chaser

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    That is some great work, that thing is going to be a tiny monster when it's done.:clap

    x2, no big deal though, IMHO all those tabs need is a rib welded down one side to stop side-side flex. For a few grams of steel you'd gain a lot of strength.

    On the oil system, if you are using the standard circuit, be aware that the big end bearing will be getting no oil while your tank fills up. That's why it's standard practice on the 640 to fill the frame separately & bleed out the air so the crank gets oil asap.

    That cam bearing failure is a bastard, haven't seen that before. I've always replaced that bearing & the other end one on mine when doing the cam followers (which are known to wear out) cos they're cheap but they've never been worn. Good luck with getting that sorted & I look forward to further updates.

    Cheers
    Clint
    #45
  6. Kennon

    Kennon Been here awhile

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    the build looks Ace, which part of the UK are you at would love to see this bike running when its done.
    #46
  7. muttley92

    muttley92 Adventurer

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    Sam, the wrap is only a tenner, well worth it I think.
    Clint, thanks is for that, I'll make sure its full before starting it.
    Kennon, im in Loughborough until the end of term.
    I've found a guy in Hinckley that does self supporting carbon seat units with integral tanks that reckons he can seal mine inside as im not convinced it won't leak.
    #47
  8. Kennon

    Kennon Been here awhile

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    Ahh nice, how is the build going?
    #48
  9. muttley92

    muttley92 Adventurer

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    It's on hold for a while whilst i get exams out of the way. It'll get finished when i get home for summer. The plastic tank leaked and I wasn't happy with it so I'm having an alloy one made up at the moment. Should just be a case of bolting it all back together when the engine has been rebuilt. The front indicators need wiring up and all the bolts need spring washers or locktite. Then get the fueling set up before the mot.
    #49
  10. Kennon

    Kennon Been here awhile

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    Thats fair enough, what are you studying? my bike won't have any serious work until the end of may.
    #50
  11. muttley92

    muttley92 Adventurer

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    I'm second year mechanical engineering at the moment. Got a placement next year and two more years of the degree afterwards.
    #51
  12. Kennon

    Kennon Been here awhile

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    ahh very similiar to what i'm doing Automotive engineering second year but carrying straight on to hopefully finish in two years time.
    #52
  13. Droptarotter

    Droptarotter Long timer

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    Use both!
    #53
  14. muttley92

    muttley92 Adventurer

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    I've built it up 4 times on my own now. Can get the engine in and running in a couple of hours =)
    Since the engine is out at the moment I figured I'd do some painting.
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    Now the big question....? Do I go with an Orange mud guard or Matt Black?
    #54
  15. Droptarotter

    Droptarotter Long timer

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    It's starting to look like a proper KTM!

    Cheers
    #55
  16. k-moe

    k-moe Long timer

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    Orange on the uprights, using the angles as a guide. Flat black on the rest of the fender.
    #56
  17. Dazed Productions

    Dazed Productions Been here awhile

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    Seriously good build, nice one! I am in the UK and starting to wonder what to build with a 690 engine I have sitting about. Thinking more of a scrambler type thing myself though.
    #57
  18. muttley92

    muttley92 Adventurer

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    the 690 definitely won't fit in the rs 125 chassis. The 640 is a squeeze. I'm thinking of designing a frame for the 690 lump next year in CAD. Simular to that of Tigcraft which used to run in the supermono series. I've got a few ideas up my sleeve but I'm not revealing too much just yet... Want this one finished first to get an idea of what I'm really playing with.
    #58
  19. Honkey Cat

    Honkey Cat Tailights Fade!

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    pretty boss looking, a bad ass 300 two smoke would be sweet also.
    #59
  20. muttley92

    muttley92 Adventurer

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    #60