G650X Challenge Rebuild or Parts

Discussion in 'Thumpers' started by Mondloch, Aug 1, 2019.

  1. Mondloch

    Mondloch n00b

    Joined:
    Nov 11, 2010
    Oddometer:
    3
    Location:
    Texas
    Hey fellow inmates. Just finished an epic ride of the IDBDR with my idiot friends, on the final day, my 07 X Challenge wouldn’t start when trying to leave our final camp spot. It had been very cold the previous night and the bike has always been slower to cold start. Tried bumping it, tried jumping it. Long story short, we ended up strap towing the bike 50+ miles to Arco, ID where the great guys at Lost River Honda started tearing her down to diagnose the problem.

    We got past the battery, fuel pump, starter and a host of other items. The plugs weren’t fouled but had a lot of carbon on them. A peek down at the cylinder wall and piston revealed a ton of carbon build up, massive scoring and at that point the tech asked if I wanted to continue. I’m no mechanic but he said we’d probably be looking at a rebuild. The thought is that an aftermarket map installed by the previous owner caused serious inefficiencies in fuel burn.

    I’ve rebuilt a cb750 motor, from splitting the cases up.

    The question would be is it worth it to dig in on this given resources, parts availability, this forums knowledge to try to get her back up or should I part her out.

    The bike aesthetically is in fantastic shape, it has the touratech tank, a rally fairing, perfect wheels. The thing only has 10,000 miles for the love of god.

    Contemplating what to do as I sit in the Salt Lake City airport about to fly home to Houston with a broken bike in storage in Idaho.

    Any thoughts?

    Attached Files:

    #1
  2. Boricua

    Boricua Long timer

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    Jul 3, 2009
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    1,614
    Location:
    Parker, CO (Suburbia, Generica USA)
    NADA avg retail value put that bike at $3,240. If that's of any value to make a call about what to do.
    #2
  3. HunSolo

    HunSolo Mad Monk Supporter

    Joined:
    Sep 14, 2007
    Oddometer:
    514
    Location:
    Cowtown Oregon.
    That looks like a really nicely equipped X Challenge. Rebuilding should be mostly a top end job at 10k miles and you'd be all set up for the COBDR next year.
    #3
  4. Wheelhorse1

    Wheelhorse1 Adventurer

    Joined:
    Jul 27, 2016
    Oddometer:
    34
    If you decide to part it out, I'd be interested in a bunch of goodies on it.
    I would rebuild it, if it was me.
    #4
  5. alexbristol

    alexbristol n00b

    Joined:
    Aug 9, 2019
    Oddometer:
    2
    Location:
    Bristol, UK
    If this happened here in UK then the tech should be advising a re-bore as it is a fairly routine and straight forward task, and it is only minor mechanical issue scoring of the bore (compared to what could happen), and from your comments the rest of the bike is sound and should give you many more happy years and miles of service. You should also ask them to check the old oil, has the metal from the cylinder liner caused damaged to other parts of engine or did the oil filter catch the metal bits all okay, looking for groves in camshafts and the plain bearings should answer this, if little or no groves then everything should be good and oil filter did a good job. Ask techie to show you camshaft and explain what damage would happen to it if metal in oil.

    I suggest you ask the tech to cost out re-bore, new piston, rings, gasket set, valve cover gasket (£24), oil and filter change, new spark plugs (£10 each), air filter (£15) and check valve clearances at same time, it should only be a few hundred GBPs/dollars. And to fix the underlining thing that caused the problem, this cost is unknown and can they properly fix it. Ideally you want a BMW motorrad dealer/engineers working on your bike, also ask what warranty they give with their work.

    Then cost out disposing the bike and buying a replacement plus all the extras it needs.

    You will then have your answer. If work is done then make sure they stamp 12,000 BMW service book as done.
    #5
  6. Beezer

    Beezer Long timer Supporter

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    Anchorage, formerly Spenard (hub of the universe)
    what he said. I would rebuild it, wouldn't even think twice about it. a bore job, piston, rings, gaskets and redo the ECM flash. gotta be cheaper than buying another skooter (that you have to farkle)
    #6
    Antti likes this.
  7. WayneC

    WayneC Long timer

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    Oct 3, 2008
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    Location:
    Sydney, Australia
    What "aftermarket map" was supposedly installed ?
    #7
  8. Motopsychoman

    Motopsychoman Not a total poseur Supporter

    Joined:
    Jun 2, 2013
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    Location:
    Oaklandish
    There are some good, whole G650GS motors on Ebay for fair prices. Even the cams are the same. Might be another way to go.
    #8
    cgguy09 and Antti like this.
  9. Antti

    Antti Been here awhile Supporter

    Joined:
    Mar 14, 2003
    Oddometer:
    490
    Location:
    Finland
    If it is the tarbon build up isn't it then cleaning, gasket set and piston rings? So mainly work.

    I tought these can't be remapped easily and usually go Power Commander route. There might be some "power plug" too in the bike.
    #9
  10. alexbristol

    alexbristol n00b

    Joined:
    Aug 9, 2019
    Oddometer:
    2
    Location:
    Bristol, UK
    Good point Antti, a remap is unlikely. For the cause I would look for something much more likely like the air filter, they are not very big on G650X and if doing any off-road then they need checking/changing greater than the regular 6,000/12,000 mile service intervals. It's an easy job you can do yourself, assuming that aftermarket petrol tank can be moved out the way easily as the standard air box will be underneath, ask the tech to show you. The standard air filter should look like this and BMW OE is £15: [https://www.sportsbikeshop.co.uk/mo...rHWmUXY0JEnO9OislvIGvUY6rcCx-_doaAvxwEALw_wcB]
    #10
  11. tele-steve

    tele-steve ya' mon

    Joined:
    Sep 28, 2006
    Oddometer:
    274
    Location:
    The Peoples Republic- Rocky Mountain Edition
    I would say to do the rebuild yourself. If you're mechanically inclined, all it takes is some space, patience, and time. If you don't have to split the case, then the project is much easier. Your most expensive line item might just be the cost to get your bike from Idaho to Houston.

    Sent you a PM with some more info.
    #11