HELP! 640 Adventure.

Discussion in 'Australia' started by Falcon Rust, Jun 15, 2013.

  1. Falcon Rust

    Falcon Rust Adventurer

    Jun 13, 2006
    Brisbane, QLD
    i need someone with some knowledge to help me figure out why it's so hard to start my 640 Adventure.
    i have charged the battery, pulled the decompressor lever and the engine struggles to turn. I also try to kickstart it but i really can't crank it easily (noob). I have tried for 10/15 minutes ever day, an sometimes, all of a sudden, she starts. this is day in, day out.

    The previous owner had an extensive service done. bike has 24,000Kms.

    i am really getting quite shitty about this. when she goes she's fine, but with this issue, i am so frustrated.

    Can anyone in Brisbane help me figure it out?
    I am in New Farm.


    ps: i am happy to pay you in Beer.
  2. Saronkhye

    Saronkhye Adventurer

    Feb 17, 2012
    Perth, Australia
    Hi, I,m currently having problems with my starter, if you goto the ktm640 thread under thumpers there is a fault finding how to, have you check relay, 20 amp fuse, wiring, my starter problem is in the sprag clutch (starter just wirrs)
    I kick my 02 by doing the following
    Petrol on
    Little choke 1/4
    Slowly kick bike to compression stroke ( kick starter won't move)
    Pull in manual decomp, so just past compression stroke, about 1/4 movement of kick starter.
    Release decomp and good kick off kickstarter and bike fires up every time.
    Also if you google ktm640 electric start you will find info.
    All the best
  3. stujamur

    stujamur keep rollin rollin rollin

    Dec 12, 2009
    Brisbane north side
    Mate this website is great for trouble shooting and general bike mechanical.. I use it heaps to get my head around stuff.

    It will run you through things to check and it is always good as you will learn lots in the process (things that may be invaluable if you ever break down in the bush) .. Valves may need checking as can be a sign of hard starting .
  4. Uncle Crumpet

    Uncle Crumpet Been here awhile

    Jun 6, 2010
    Eidsvold, QLD
    get the battery load tested, don't matter how much you charge a stuffed battery, it will still not start your bike.
  5. mcguyver

    mcguyver Long timer

    Dec 24, 2005
    Danielle give me a call and we can arrange a time for e to come round fir a look.
    Not that I'm an expert, but might find something.
  6. Falcon Rust

    Falcon Rust Adventurer

    Jun 13, 2006
    Brisbane, QLD
    thought you were away.

    i'll call you later. Sage manages to start it with a kick, but i am convinced there's something going on. can't be this hard.
  7. XRman

    XRman Long timer

    Dec 9, 2006
    SW Victoria Oz
    drain the carbie float bowl.
    add fresh fuel to the petrol tank.
    See if it makes any difference to ease of starting.
    WHen you stop riding , turn off the fuel and let the engine run until it conks out. You won't have any fuel in the float bowl to go "off"
    Get the valve clearances checked.
  8. Dee Cee

    Dee Cee Been here awhile

    Mar 6, 2006
    Newlyn. Victoria.
    Well where to start ( no pun intended ).

    I've had a 2003 640 Adv for about seven years and 60,000 Klicks and it has always been a battle of sorts to start. I have long since got the knack to kick her with my left leg which felt awkward at first, like using your other hand to clean your teeth. For a bike that I enjoyed riding so much it really started to piss me off.

    So decided to fix her and I have done just about everything you can think of.
    After initially going thru a couple of batteries including the expensive Yuasa YTZ 10S I settled on a slightly larger Deca which I had to modify where my regulator sits to fit it in, then I stripped all of the start circuit out and checked and cleaned every thing and put back, I ran an extra earth wire direct from the battery neg to ground on the actual starter, I removed the starter, stripped it and found it pretty sad inside, so new brushes made up at the local auto elect and there is a little bush at the non driving end of the starter that dries out so it was greased.

    Then out with the sprag clutch and replaced it as it was looking a little old.

    I tried all sorts of starting techniques over the years and the only thing left as far as I could see was the auto deco on the cam must be dodgy. So out with the cam and I spent about an hour rolling it around in my hands until I understood how it works, very nifty I must say. Once I did this I could see where the weakness was in the design. I spent about 5 hours with emery tape and a small file increasing a little shoulder that allows the deco to do its job and BINGO:clap all the other work came home to roost, now she starts like it should. These things have a shitty auto-deco in them from the word go and I am not sure how long my repair will last either. The cabie come fuel system doesn't help either as the fuel is fed by a vacuum pump and the carbie has no pumper in it to give a squirt to richen it up before a cold start. My mate has a 625 and his fires up well all the time. I am about to put a 41 mm FCR carbie on her so I will be most interested to see how starting is after this. Even now when cold the bike needs to wind over well for longer than I would like and I blame the fuel system for this and before I fixed the auto deco it would just take too much out of the battery to get the fuel through and to fire the ignition circuit with some grunt but now it starts just fine. I am hoping the new carbie will shorten crank time when cold.

    In its present state the bike starts instantly when warm and I mean instantly.:lol3

    All of this happened slowly over the last six years.

    I hope it is of help to you.
  9. richo360

    richo360 Long timer

    Sep 5, 2011
    Bottom of the barrel and still digging
    They way I read it you're cranking (or kicking) it over with the decomp lever pulled in?
    If you are, Don't.

    It's only for kicking it over to TDC before kick starting it. Which you dont need to do anyway, imho. Or you can hold it in whilst cranking over to clear a bit of water out if you've drowned it.

    Maybe I read your post wrong, but my 2c worth.

    If its cranking really slowly, chech started leads, battery and starter solenoid earth, and/or consider removing and rebuilding starter. Could be brushes are seized in place and not contacting with commutator, or there's am issue in the windings.
  10. Colonial Mick


    Mar 18, 2009
    Upper Cumbucter West. Armidale/Kempsey Rd.
    Well done you have a lot of patients Dee Cee .I know the feeling when you suceed its a great sence of achievement !:clap
  11. pugsley

    pugsley Little Man

    Jun 13, 2006
    wollongong South Coast NSW Australia
    I also have a 2003 model......this year was notorious for exactly that problem,it appears there was a batch of "bad "cams that went out.....I have spoken to several other owners of 2003 models who have experienced the same thing.....