Yamaha XT500

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

  1. g®eg

    g®eg Canadian living in exile

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    you might need to make it public or shareable.
    BTW, another WA state XT covid project here too :beer
  2. Jzxt500

    Jzxt500 Adventurer

    Joined:
    Apr 21, 2021
    Oddometer:
    11
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    Windy Point WA
    Yes, Ive been looking at your thread and bike. Just got my nice 77 XT in January and I’m going through it, mostly just cleaning it up. Did have to de-rust the tank and a little solder job on it, came out good. Overall I think it might be a low-mile, old XT, probably last registered in ‘93.

    Attached Files:

    Old Smokey and johnclaude like this.
  3. g®eg

    g®eg Canadian living in exile

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    nice!
    I didn't have a lot of stuff (turn signal, mirrors, etc) but it has them now
    it had an exhaust off a TT when I got it (very loud) but has the Kedo replica stock exhaust now.
  4. Jzxt500

    Jzxt500 Adventurer

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    Oddometer:
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    Good on the exhaust. Parts for these are rare now, not sure why. Very sought after.
    I’m like you and want to have a stock bike. And my carb body has some damage, Im looking for that. (It still works thankfully). I’m on the Peninsula.

    Attached Files:

  5. Old Smokey

    Old Smokey Long timer

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    IMG_4184.jpg

    Got my 77 xt500 that pretends to be a TT out today for a nice 80km dirt ride.

    First time of the season and only the forth or fifth ride since rebuilding it entirely.

    Couple questions for the XT owners out there:

    - when I brake hard I feel something clunking a little bit in the front end. It only happens on hard braking. Not sure if it’s some kind of slop in the forks, or if it’s coming from the drum. Any ideas? I can’t find anything obvious. Front brake has new pads. Forks were rebuilt but I didn’t replace the upper bushings. New tapered steering bearings.


    - this engine sure is noisier than my four valve thumpers (Honda xr). I have a wiseco piston and heavy RD springs. New cam chain, tensioner, valves and tappet adjusters, cam and rockers. Everything is new up there. The cam chain tensioner has been set when hot as per the book. And my valve clearances are set per the cam specs and haven’t changed since putting on the first 500km. I also put new fin dampers in. Nature of the beast? I’ve heard some nice quiet XTs on YouTube and was hoping for a more refined sound lol. How do the XTs here sound?


    Outside of that, what a fun bike!
    Peke and johnclaude like this.
  6. Old fart

    Old fart Keen AG100 rider

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    Sounds a bit like steering head clunk, how's your bearing adjustment? I found the wisco piston noisier than the standard Yamaha one. If the camchain tensioner is adjusted properly the engine shouldn't be too noisey. With that supertrap exhaust it's lucky you can hear any engine noise
  7. Old Smokey

    Old Smokey Long timer

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    I replaced the bearings with new All Balls tapered bearings. I can't feel any clunking by hand. The clunks I feel on hard breaking do sound like steering bearings though. It's just odd that I don't feel it all the time or on slow breaking. I'll check the preload on them again to be safe.

    Cam chain has a new rubber damper and was set to the rod has the faintest movement in it. I tried over-correcting it for a few seconds for comparison but didn't hear a change in sound.

    I think the noise is either the valves tapping, the piston, or both. The Wiseco has more clearance than the stock cast piston, but once warmed up it should be the same. I don't notice any change in the engine noises cold vs hot either. And like I said, the valve clearances are spot on and have stayed the same since engine build to today. Might be chasing nothing here as I haven't heard another XT in person.
  8. plugeye

    plugeye MC rescue

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    also check the brake plate for looseness between it and the fork interface
  9. Old Smokey

    Old Smokey Long timer

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    Fixed the clunk. It was the steering bearings. An extra 1/8 turn and it disappeared!
    plugeye and g®eg like this.
  10. johnclaude

    johnclaude Adventurer

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    Nov 12, 2009
    Oddometer:
    77
    Location:
    Denver, CO
    Anyone in the states have a seat that will fit an 1977 XT500? Finally got my project up and running. Had a bad coil, and the points were timed 180 degrees out. Fired right up after that! I have some airbox parts I would be willing to barter with. Or cash money. Let me know!
  11. Old fart

    Old fart Keen AG100 rider

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    If you do a lot of long wheelies that setup will make a mess. When you wheelstand an XT past about a K the oil comes up from the back of the gearbox and floods into the airbox. This makes the oil go into the airfliter and "smokes it up". You loose power and leave a massive smokescreen. When people tell you they can wheelstand an XT 500 forever, they are telling porkies.
  12. Old Smokey

    Old Smokey Long timer

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    My XT engine has a bit of an 'agricultural' sound to it. The engine is fully rebuilt, top to bottom, but I have an overly ticky rocker box. New cam, rockers, valves, tappet adjusters, springs, piston, you name it. I think my rocker spindles must be a bit loose in the rocker box. I've read a lot about the 'grub screw mod' to keep the spindles locked into position, and am going to give it a go. I have the M6 grub screws, Loctite 263, and a fresh 5mm drill and m6 tap in hand.

    Before taking the top off though, figured I would built a quick engine service stand.

    I have some scrap steel laying around and banged out this simple unit. I'm new to TIG welding. this is maybe my fourth or fifth little project and am having a blast!

    I'll start the grub screw mod this week and share some details, including before/after video of the engine sound for future reference here.

    Attached Files:

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  13. plugeye

    plugeye MC rescue

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    good job on the stand
  14. Jzxt500

    Jzxt500 Adventurer

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    pm me|
  15. Jzxt500

    Jzxt500 Adventurer

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    Oddometer:
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    Windy Point WA
    5EDA9BE9-98FC-4FB2-B4E0-90350317EE3F.jpeg
    showing off my KEDO twin-feed oil line to the rockers, just installed yesterday. This should extend engine-life a little, right?
  16. Old fart

    Old fart Keen AG100 rider

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    I did over 50K on my first XT with no problems with the original single oil feed
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  17. Jzxt500

    Jzxt500 Adventurer

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    Yes! (50K on a dirtbike boggles the mind).
    I put the dual oil pipe on it from the recommends from others. And it sounds right to me.
  18. Old Smokey

    Old Smokey Long timer

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    That is impressive! Did you have the engine apart after 50k? How did the top end look?
  19. Old fart

    Old fart Keen AG100 rider

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    It was still running well, I sold that and was sorry. I then immediately got another and have always had one or 2 XT's since. I got my first in 76, it had an aluminium tank the same as the TT, came with it standard. A plastic 15 litre tank helped the fuel range, I did a lot of off-road as well as touring.
    I have 2 still, one was used for a string of bank robberies. The bloke went to a bike shop and asked for a bike that started easily and was reliable He was caught, when he was arrested he said there was a large amount of cash. That disappeared, the detective that arrested him was bent. The bank robber did a few years in jail, the detective retired and became a book maker at most country horse races. I worked with the bloke after he got out of jail, he was a pretty decent fellow
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  20. Old Smokey

    Old Smokey Long timer

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    Hah!! Legendary story!