Old fart buys old CX500

Discussion in 'UK Motorcycles' started by Chris Malcolm, Jun 25, 2005.

  1. After several years of illness and financial embarrassment I've
    recovered. Found a running Honda CX500 at less cost than it would take
    to get my Guzzi V50 back on the road, so I bought it. 1981, 35,000
    miles. At worst it will give me transport until I get the V50 going,
    which needs new carbs, hardened valve seats and top end rebuild, and
    probably a shaft drive strip and rebuild.

    Am assembling a checklist of problems CX500s of that kind of age are
    prone to. So far I've got rear swing arm internal rusting and battery
    charger. Any more suggestions?
    Chris Malcolm, Jun 25, 2005
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  2. Chris Malcolm

    Muck Guest

    I've heard of the cam chain tensioners being trouble on some.
    Muck, Jun 25, 2005
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  3. Chris Malcolm

    mb Guest

    Cam chain tensioner, IIRC.
    mb, Jun 25, 2005
  4. Chris Malcolm

    TMack Guest

    Worn cam chain and tensioners (this is the MAJOR CX500 weak spot - if not
    sorted can cause the cam chain to start chewing through the crankcase -
    listen for clatter), stripped thread on cam tensioner adjuster (unless its
    automatic), mechanical seal (internal water seal - look for drips of water
    under engine), alternator (first symptom is usually inability to get much
    over 50mph), leaking camshaft oil seal (look for oil seepage from behind fan
    and down the front of the engine - quite easy to replace not a major

    Parts are easily obtainable and not outrageously expensive. Bike is quite
    easy to work on. Generally the engines are pretty bomb-proof so its
    unlikely to have major mechanical problems.

    I suggest that you visit here

    TMack, Jun 25, 2005
  5. Chris Malcolm

    BORG Guest

    Can be fixed easy by putting in a larger threaded bold, just tap and

    the 'Mk2's was fixed and the Silverwing 650s, but that's irrelevant to
    you :)

    change head bearings for tapper rollers,

    progressive fork springs and new rear shocks help as well and check

    That's all I can think of.

    <--ROT13 it
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    GS850 Trike

    For animals, the entire universe has been neatly divided into things to
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    BORG, Jun 25, 2005
  6. Chris Malcolm

    TMack Guest

    That might cure a stripped thread problem with a tensioner bolt (although a
    helicoil with the original bolt is better) but it won't cure a badly worn
    tensioner (and the almost certainly knackered cam chain if the tensioner is
    worn) will it? Also it isn't quite so "easy" when you look at the problems
    accessing the damned thing in the first place (engine out).

    TMack, Jun 25, 2005

  7. The swingarm and the alternator are the main probs on old ones.

    Camchain - as a 1981 model, it'll be an A or B and they were fixed by
    then, so if it isn't rattling, ignore the doomsayers elese where in this
    thread and just ride it.

    Check the rad - they tend to corrode and leak at high miles. Water leaks
    from the pump seal. The rest is just the usual stuff - chrome, bearings,
    fork seals, etc. etc. The engines run for ever.
    The Older Gentleman, Jun 25, 2005

  8. See other post - they had it sorted by 1980.
    The Older Gentleman, Jun 25, 2005
  9. Chris Malcolm

    Pip Luscher Guest

    If it's a Eurosport (don't know which year they came out) then the
    pro-link bushes do seize if not maintained, but because the bolts
    simply rotate instead of the bushes, there's no obvious symptom until
    the back end collapses. This happened to a colleague.

    Check the rear wheel splines.

    A knackered rear wheel bearing can spin in the hub wearing the hub
    out. Not limited to CX500s, though.

    If the bike's been dispatched then ignore the odometer!

    Water pump impeller can work loose and strip splines.

    Water pump mechanical seal can leak - check for water on crankcase
    behind cylinders.

    Apparently the valves can recess; certainly mine never went over 95mph
    but I never had the heads off to verify that this was the cause.

    The original collector box is probably long gone; they all rust.

    It may sound awful, but they're easy to work on and they burble along
    nicely. I bought in haste and ended up paying way over the odds for a
    pup, but I still like them.
    Pip Luscher, Jun 25, 2005
  10. Chris Malcolm

    TMack Guest

    You mean they stopped the tensioner breaking completely without warning by
    re-designing it - they didn't stop it wearing and they didn't stop the cam
    chain wearing and stretching.

    TMack, Jun 25, 2005
  11. All camchains wear and stretch. The CX's was as solid as they come from
    the A model onwards.

    I suppose you'll get the odd failure here and there, but if t's sounding
    quiet, I wouldn't worry about it.
    The Older Gentleman, Jun 25, 2005
  12. Chris Malcolm

    TMack Guest

    Agreed - no noise, no problem. However, they can be badly worn (crankcase
    chewingly so) at as little as 35,000 miles. Given that it is an engine out
    job to replace the cam chain, this is one of the first things I would check
    on any CX500


    TMack, Jun 25, 2005
  13. Yeah, but how are you going to do that?

    You're not going to be able to drop the engine to have a squint at the

    Just listen to it. If it's quiet, fine. If not, walk away.
    The Older Gentleman, Jun 25, 2005
  14. Chris Malcolm

    Kitchen Man Guest

    On Sat, 25 Jun 2005 11:53:21 +0100,
    I knew a guy who had two CX500's and tried to build one good one out
    of the two. He had the water pump problems you mention, and never did
    get it sorted out. He was kind of an idiot, and a dishonest one at
    that. Stole my battery charger, the bastard did.
    Kitchen Man, Jun 25, 2005
  15. Name & shame! Name & shame!
    The Older Gentleman, Jun 25, 2005
  16. Chris Malcolm

    Kitchen Man Guest

    Name & shame! Name & shame![/QUOTE]

    He was known to me only as Lone Pine Louie. He's probably wandered
    off somewhere into the sage desert hills of Southern California.
    Kitchen Man, Jun 25, 2005
  17. Chris Malcolm

    muddycat Guest

    He was known to me only as Lone Pine Louie. He's probably wandered
    off somewhere into the sage desert hills of Southern California.[/QUOTE]

    The **** must have come up here then as someone nicked a neighbors
    battery charger yesterday.

    Skype: muddycat
    muddycat, Jun 25, 2005
  18. Chris Malcolm

    TMack Guest

    FFS "check" = "listen for camchain noise". We do not have a difference of
    opinion here. However, if one wanted to be REALLY sure with a manually
    adjusted chain then the procedures are as follows.

    "To check the manually adjusted cam chain tensioner life, rustle up a dental
    mirror and a torch, look inside the rear crankcase timing port. Or feel with
    a fingertip. The adjusting quadrant should have at least 1/4 of an inch of
    its slot visible above the locknut. If there is no visible gap, the
    adjusting arm is at or near the end of its adjustment and soon you will need
    to change the cam chain and tensioner."


    "Another way to detect a worn cam chain on Zs, As, Bs and GL500s is to peer
    behind the radiator at the fan, which is attached to the front end of the
    camshaft. Put the bike in 5th gear and very gradually wind the engine to and
    fro by nudging the rear wheel. There should be no movement of the flywheel,
    visible and feelable through the timing aperture, without a corresponding
    movement of the fan. If there is slack in the cam chain, the crankshaft will
    be able to move a fraction without a corresponding camshaft / fan movement.
    This trick does not work with the electric fans of the 650s."


    TMack, Jun 25, 2005

  19. Well, quite.
    The Older Gentleman, Jun 25, 2005
  20. Chris Malcolm

    Bob Mann Guest

    Rear end seals.
    Bob Mann

    Before you critisize someone,
    you should walk a mile in their shoes.
    That way, when you critisize them,
    you're a mile away and you have their shoes.
    Bob Mann, Jun 25, 2005
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