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Yamaha XT500

Discussion in 'Thumpers' started by TimberlineAdventure, Mar 29, 2008.

  1. Old Smokey

    Old Smokey Been here awhile

    Joined:
    Dec 9, 2014
    Oddometer:
    975
    Oh man, that is a beauty, snag it quick!!
    g®eg likes this.
  2. brucifer

    brucifer Long timer

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    Nov 27, 2007
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    Eureka, Ca.
    plugeye likes this.
  3. g®eg

    g®eg Canadian living in exile

    Joined:
    Jul 13, 2004
    Oddometer:
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    Location:
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    so i got the bike
    running poorly, very rich
    so i am thinking carb rebuild is in order

    now i’m stumped
    the carb is stamped IT1 60, and i am trying to figure out exactly what kit to get
    i figure going back to stock is the best place to start

    is that enough information to point me in the right direction?
  4. plugeye

    plugeye MC rescue

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    6,885
    Location:
    Garland, Texas USA
    probably not. put up some detailed pics of it & measure the I.D. of the throat on the engine side. should be 32mm or 34mm
  5. g®eg

    g®eg Canadian living in exile

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    OK

    measure the engine side, looks like 1.36 to 1.37 inches.. yeah yeah I know "inches" but that's the dial caliper i have.
    so 34.5 mm to 34.75 mm ish?

    I emailed the guys at vintage spoke, they reckon it needs this rebuild kit: LINK
    all the bits look pretty similar. I just don't want to end up being overly rich still.
    of course the jets currently in the carb look like someone used vice grips on them... gnarly, no numbers

    I figure going back to stock, or as close as possible, is my best starting point.

    anyway, tips and comments appreciated!
    I got some of those little ring-stop things (102-25137-00) and fitted the tach cable and the speedo cable.
    Looks like the rear brake switch is bad, so that's on the list to replace. Front works though, and brake light / tail light / headlight (hi & low) seems to work OK.

    I'd like to put turn signals back on at some point, to make it closer to stock.

    need to bolt up the bash plate still (figure out what size bolts holds that puppy on).

    oh, and some mirrors.. they look cheap enough on eBay.

    picture attached

    IMG_2483.JPG
  6. plugeye

    plugeye MC rescue

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    looks like the right one, VM34SS stock on 1976 XT500 and TT500
    g®eg likes this.
  7. g®eg

    g®eg Canadian living in exile

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    thanks @plugeye :beer
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  8. g®eg

    g®eg Canadian living in exile

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    Oddometer:
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    Location:
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    so stupid question...
    rebuild kit arriving today.

    I have been scouring the web for an exploded parts diagram for the VM34SS, and while I've had pretty good success finding some detailed drawings, none of them mention this little ball. (circled in picture)

    I know I had one in my crab, because it was sitting on the towel I laid out while disassembling... of course I didn't see where the little bugger came from.

    any help?

    thanks! 94038_20171227094920.jpg
  9. Michel59

    Michel59 Adventurer

    Joined:
    Nov 7, 2017
    Oddometer:
    72
    Location:
    France
    The ball and spring are the positive stop of the starter lever, means between lever and carburetor body.

    Hope this help.
    g®eg likes this.
  10. g®eg

    g®eg Canadian living in exile

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    yeah I think i finally found it...
    #64 I think

    [​IMG]
  11. Michel59

    Michel59 Adventurer

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    France
    Yes #63 & 64. Don't ask how I know :jack
    g®eg likes this.
  12. g®eg

    g®eg Canadian living in exile

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    LOL....
    sounds like you work the same as me.
    do it once (wrong) then do it the second time (correctly).

    one day I'll get it right first go

    thanks!

    :beer
  13. g®eg

    g®eg Canadian living in exile

    Joined:
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    Location:
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    so an update to my progress...

    The fellow I bought it off had been tinkering with it and said "it's about 70% of the way there".

    so anyway.. I get it home and start looking at it. He told me it was running quite rich (black / fluffy spark plug). I confirmed this.
    So I figured (right or wrong) that maybe a carb rebuild was in order. I had read about worn needles, etc and figured no biggie.

    I got the carb kit from Vintage Spoke for the VM34SS carb that was installed (Carb stamped IT-1 60)
    The kit went in easily enough. At the same time I had noticed a bit of a dribble out of the over-flow. A quick scan of the XT forum pointed me to a cracked overflow tube, which I confirmed and repaired with JB Weld and a paint brush (thanks for that tip).

    Anyway, carb reinstalled, choke on, fire it up 2nd kick, no worries. Let it warm a bit damn this sucker is loud... can the stock muffler be repacked? It doesn't have its spark arrestor anymore. But I digress...so it's warmed up, and I ease the choke off and it dies.

    Bugger

    Bit of choke on, stab it to life, same drill.

    so I am a bit stuck right now.

    I thought maybe an air leak around the carb intake manifold boot, so with choke on, running about 3000 rpm, I sprayed some WD40 in the area. No change at all.

    As I say, it sort of ran OK when I got it (that is to say too rich, but it would idle until the plug got so fouled it said no more).
    I am trying to think what I have screwed up, short of putting all the old bits back in. The needle, needle jet & main jet should make no difference to idle. Maybe I need to put the old airscrew back in (with the new pilot jet still installed).

    anyway... any help will be greatly appreciated

    thanks

    Greg

    (pic of the bike, just because)
    it has a stock pipe now, and I think the previous guy put the shocks on upside down when he reinstalled (they are opposite of what this picture shows with the adjuster at the bottom). I guess that'd be something else I can work on...

    PDRM2005(1).JPG
  14. plugeye

    plugeye MC rescue

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    try setting the mixture & idle so that you can ride it until its hot. then adjust the mixture for strongest idle and reset the idle to 1100-1200. also check points gap & timing
  15. g®eg

    g®eg Canadian living in exile

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    sounds like a plan.... but I can’t keep it running w/o choke at the moment

    Maybe I try the old pilot jet and air screw?
    If that’s a no go then I might try going back to the old bits and see if I can make progress from there
    I do need to check points and probably the valves as well just to be sure

    thanks!
  16. Michel59

    Michel59 Adventurer

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    Oddometer:
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    If you remove the part #3 on the diagram buy pushing it out and go a small wire from the back small hole of the carburetor, you will free of the opening. That helps sometimes with the problem you are facing.
    Sorry fo rmy bad explanation, I am just French :jack
  17. g®eg

    g®eg Canadian living in exile

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    Hi Michel

    it's OK, your English is better than my high school French :beer
    got it running last night. seems like setting up at 1.5 turns of airscrew was too many
    I got a good idle and doesnt seem rich (or lean) and 1/4 turn only.

    continuing to fiddle.
    I need to do the three step carb tuning process next (idle / mid range / wide open)

    thanks
    Greg
  18. OutsiderVA

    OutsiderVA Adventurer

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    Richmond, VA
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  19. motomike14

    motomike14 Thumper Crusader Supporter

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  20. OutsiderVA

    OutsiderVA Adventurer

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    Richmond, VA
    Actually already got a request for it.