640 625 lc4 KTM seized, suspected cooling problem

Discussion in 'Australia' started by unclemitty, Aug 16, 2018.

  1. unclemitty

    unclemitty uncalamity superhero

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    Enookway, i’d just let it lie. If you’re really paranoid, do a compression test but I wouldn’t strip it down just yet. Try do a few shorter rides and see if it’s going to let you down but I doubt it will. My brother rode his 02’ 640a some 300km on the highway with no coolant and it didn’t cause any appreciable damage. My seizure came off the back of a cooling system that wasn’t running properly for some 500-1000km of city riding. I wouldn’t stress about your situation anytime soon. These motors are quite robust and can really put up with a lot.


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    #81
  2. wrya1

    wrya1 Been here awhile

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    It was more like 500+km; the dealership had just done a $2000 major service/rego/tyres etc and the bike started overheating almost straight away. So when I called them to say WTF?! They said ride it back to us (other side of the state) and we will take a look, it can’t be overheating, must be a faulty gauge or thermostat.

    They wanted to replace thermostats and all kinds of things but didn’t know what would fix it. I said thanks but no thanks, and thought “better check how much coolant is in it...”. There was none. More fool me for assuming, but nevertheless. That’s when I stopped going to dealerships, except a select few. It was the water pump seal in the end, and when the main shaft bearing shat itself, the mechanic who did the rebuild didn’t see any signs of heat related damage.
    #82
  3. enookway

    enookway Are we having fun yet?

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    A compression test was where I was heading to first. Its due for a service so I will check tappets and the usual stuff anyway.

    I'm just absolutely staggered that these things can take that sort of abuse and not only keep running, but running like nothing happened.
    I thought it would at least blow a head gasket or water pump seal but theres no evidence of that.
    #83
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  4. troy safari carpente

    troy safari carpente Team f5oolery

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    looking at your photos on the (very small) screen of my mobile... it looked at first glance, like you'd planted a green succulent in the cylinder head... :rofl :imaposer

    Let's hope that all goes well and she doesn't end up as an LC4 "Allan Seale" edition... :thumbup :evil

    [​IMG]
    #84
  5. unclemitty

    unclemitty uncalamity superhero

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    Well if I botch the job I may end up posting the success of my agapanthus... or I'll just do a better job next time with the another $1000 on what could have been prevented.
    #85
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  6. troy safari carpente

    troy safari carpente Team f5oolery

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    "sthshit, by the succesth of your agapanthusthusesth... I'll sthay..." :lol3 :thumb
    #86
  7. unclemitty

    unclemitty uncalamity superhero

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    jeez I'd better get the bloody bike going then...
    #87
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  8. unclemitty

    unclemitty uncalamity superhero

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    I like to think that I'm mechanically sympathetic yet there's no denying my bike copped a relative thrashing given that it had a compromised cooling system for months of what is hard work on the motor. They really put up with a lot. In my days at the college of knowledge I spent a lot of time around the Aprilia RXV/SXV 550 v-twin engines which were a pseudo competitor of the LC4. Well they couldn't be more different in regards to reliability. Whilst both engines are great in their own ways, that Rotax built vtwin was awfully unreliable (even beyond what you may consider "reasonable" quirks, which all motors have).

    The carbureted LC4 seems to have a great legacy and it's well deserved.
    #88
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  9. enookway

    enookway Are we having fun yet?

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    Next time a DR rider bangs on about the additional complication of water cooling, I'll hand him my radiators and all the plumbing and say "see you at the next fuel stop":bubba:ricky
    #89
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  10. unclemitty

    unclemitty uncalamity superhero

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    Having a DR rider giving you a lecture about bikes is like sitting through a sex-ed class in high school; it’s mandated by the state curriculum and a thoroughly horrid experience.

    I’ll take my radiators with or without coolant, thanks.


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    #90
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  11. Brute

    Brute Melbourne , outer east .

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    A bit of talk about compression tests here . Generally you can't do it. They have a auto decomp so youll probably get around 90 psi compression while cranking the engine. Disconnect the decomp and usually the starter won't have the power to crank .
    Also if you are going to file your rings , only file from the outside in to avoid chipping the outer coating off . Not saying all rings are coated but if they are it's good practice.
    #91
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  12. unclemitty

    unclemitty uncalamity superhero

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    Good points there Brute, I forgot about the auto decomp.


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    #92
  13. enookway

    enookway Are we having fun yet?

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    Mmmmm yes, and to disconnect the auto decomp you would have to pull the cam out and remove the autodecomp cam
    #93
  14. Roofchop

    Roofchop Hands up mother stickers, this is a f**k up!

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    Leak-down test!
    #94
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  15. unclemitty

    unclemitty uncalamity superhero

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    So last night I thought I’d have the motor stitched back together but unfortunately one of my locator dowels for the rocker cover is AWOL. I recall it being very loose when I was inspecting things three weeks ago and there’s no sign of it in any old photos. Bit of a bloody pain and amateur on my part, I should’ve bagged it up when I knew it was loose. Alas, after a couple of hours searching I haven’t found it and I know it could be in quite a few places. I am confident that it’s not in the engine yet it’s still a hassle. I’m not sure if any shop has these parts in stock either... anyway, time to order one (58530090000).

    It was frustrating because I’d hit my stride last night too, it was really coming together there. (Note I took the rocker cover and water pump off and cleaned up all the Three Bond). More to come..
    [​IMG][​IMG]


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    #95
  16. UncleGra

    UncleGra Road Grime

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    My 2005 has manual de-comp. I have to use it all the time now to start it, whereas before it's so called "re-build " it was never needed.
    #96
  17. unclemitty

    unclemitty uncalamity superhero

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    The dowel pin showed up yesterday so I got stuck in last night. The rocker cover was a bit tighter than I recall going on and only pressed tight upon bolting it down. It wasn’t a big fight but I really didn’t like doing it that way, I tried many times to seat the rocker carrier/cover but was unsuccessful until bolting it down. Positively however, the valve clearances were very close to being in spec from before I pulled it down. Still, it’s not comforting to fit machined surfaces together by bolting them up..

    Anyway, I’ve got to now hook up the exhaust, pop on the new radiator hoses and radiators, dump that old oil and fire her up. I might even drop some coolant in there. Hopefully I can get another couple of hours this weekend.[​IMG][​IMG]


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    #97
  18. dnrobertson

    dnrobertson Big Bike, Slow Rider

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    Wow, that beauty still has the SAS crap hanging off the exhaust!
    #98
  19. unclemitty

    unclemitty uncalamity superhero

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    Im a generous guy, I don’t mind giving up a few horsepower to the needy DR jockies


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    #99
  20. unclemitty

    unclemitty uncalamity superhero

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    Seriously though, I haven’t been too worried by the exhaust recirculation system. I’ve never been fussed about dyno tuning the bike and I figured there’s not much point guessing how to make “an extra guaranteed 6rwhp”.. one thing I’d like to have done though was to replace the front forks for some 48mm WPs. Still wouldn’t have helped me much and probably not worth the cash these days. The 43 forks are ok and I’m less than an ok rider so they’ll do.


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