The XT350 thread

Discussion in 'Thumpers' started by Burtonridr, Sep 26, 2007.

  1. Lvcks

    Lvcks Adventurer Supporter

    Joined:
    Feb 23, 2021
    Oddometer:
    57
    Location:
    Hawaii
    Today I drove her to work after rejetting the other day. You wouldn't believe the speed! My trailtech clocked her going 91! I put did a few GPS runs to make sure it was accurate and it is + or - 1. Oh God look at that temp :jack anyways it looks like I'm getting a leak after changing the gasket on the oil filter cap. Bottom bolt. It's really minor, and I don't want to over tighten so I'm waiting for my mini torque to come in to make sure. Still have more cosmetics to do to the bike and can't seem to find the other side I need air scoop. Worked on the tdub today changing the front tire after work so my bro who flew home can ride with me. Well have a good one guys!!

    Attached Files:

  2. Caperodder

    Caperodder Adventurer

    Joined:
    Jan 14, 2014
    Oddometer:
    95
    I just can't let this bike beat me.....

    Was running like a top, was using waaaaaay too much oil. Went out to start it this morning...no compression. That's telling me I likely have a valve that's hung up. I knew they day would come, so off with it's head! Leak-down test was very good (prior to this), so I think the trouble remains top side. More to come.

    I did check the decompression setup, and it's closed. Since I need to get to this anyway, looks pretty straight forward, and pretty sure it can be done with the engine in the bike....It's spring and I want to ride not repair!
  3. Caperodder

    Caperodder Adventurer

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    91! That's pretty friggin fast on an XT!
    Lvcks likes this.
  4. Caperodder

    Caperodder Adventurer

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    Oddometer:
    95
    Ok. Right side exhaust valve is not closing. I need to have a better understanding of the decompressor and how it operates. The cable side is operating ok....and I can see a shaft with a chamfer rotating inside the head.....gotta go to the Clymer manual. There is at least .10 space between the valve spacer and the cam. When the cam rotates....it does push the valve down, but does not return to a closed position.

    IMG_6443.jpg
  5. neppi

    neppi Long timer

    Joined:
    Mar 9, 2017
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    1,569
    Location:
    Tauranga, New Zealand
    Carbon build-up. Pull it apart! Not as big job as it sounds. Even I could do it!
  6. Caperodder

    Caperodder Adventurer

    Joined:
    Jan 14, 2014
    Oddometer:
    95
    As soon as I can get the left exhaust, to free itself from the head....it's ready to be pulled. I'm going to need to get a long 8mm Allen key for a proper re-torque. I should be able to remove it with a standard "l" shaped wrench.

    Still wondering where all the oil is going. We'll know soon enough.
  7. Caperodder

    Caperodder Adventurer

    Joined:
    Jan 14, 2014
    Oddometer:
    95
    Here is the culprit. Exhaust valve stuck open. Quick tap and it popped right back in. I'm going to pull all of the valves, check the guides, and add new seals. Might as well bead blast the cylinder and head, and give it a nice coat of black paint...as well as the exhaust header. None of by valve spring compressors will work, so I'll have to get a "c" clamp style spring compressor.

    Piston, rings and cylinder walls look perfect.

    IMG_6445.jpg
  8. JensEskildsen

    JensEskildsen Long timer

    Joined:
    Mar 24, 2009
    Oddometer:
    2,450
    Location:
    Denmark
    Add a freh o-ring for the oilfiter, it sould take very little torque to compress and seal it.
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  9. Caperodder

    Caperodder Adventurer

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    Oddometer:
    95
    Will do. Thanks!
  10. Caperodder

    Caperodder Adventurer

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    Jan 14, 2014
    Oddometer:
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    Got the valves out. The valve guides look excellent, but the seals were brittle and cracked. Hopefully, that's where the oil was going.

    My guess is, that when the PO had this thing out in the yard, under the tarp, the exhaust valve was open, and the shaft ended up with some corrosion on it. Should be able to just get a top end gasket set, some Kibblewhite valve seals and bolt it all back together. I think I'll also just lap the valves ever so slightly.
  11. neppi

    neppi Long timer

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    I had the same! Is there like an extra groove in the valve shaft? Never seen that before...

    Now if you put new seals in with the old valves, the groove in the valve shaft rips through the new seals again. I bought new exhaust valves and all was sweet again.

    That head doesn’t look bad! Is the piston in same cond? Just clean everything up, new valves, new rubbers and you’re good for another gazzillion Kms.
  12. Lvcks

    Lvcks Adventurer Supporter

    Joined:
    Feb 23, 2021
    Oddometer:
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    I am as surprised as you are haha. Though I don't plan on using that kind of speed often before I blow it up :jack
  13. Lvcks

    Lvcks Adventurer Supporter

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    Feb 23, 2021
    Oddometer:
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    I just put a new o ring in there. I shouldn't have touched it because it didn't leak beforehand haha when the torque wrench comes in I'm sure it'll be okay
  14. Caperodder

    Caperodder Adventurer

    Joined:
    Jan 14, 2014
    Oddometer:
    95
    Anybody know what color "yamaha" blue a 1995 XT350 is? I thought it was Ink Blue, but now I can't find any reference to that name.

    Thanks.
  15. ADV1602

    ADV1602 n00b

    Joined:
    Oct 29, 2019
    Oddometer:
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    According to the OEM part finder at Partzilla.com, everything on the '95 is "Ink Blue" except for the frame and fork boots. Does that answer your question, or are looking for a more official Yamaha reference?
  16. Caperodder

    Caperodder Adventurer

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    95
    I though so....I thought I saw Ink Blue in rattle cans, but have been unable to find a source.
  17. Lvcks

    Lvcks Adventurer Supporter

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    Hawaii
  18. ADV1602

    ADV1602 n00b

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    Oct 29, 2019
    Oddometer:
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    Location:
    USA
    The factory service manual warns about a bur that is formed on the valve stem by the retainers.

    valve stem.jpg

    I'm wondering if neppi is cautioning about damaging the new stem seals during installation, or if he is talking about the surface of the valve stem actually being rough enough to damage the seals during engine operation. When I removed the valves from my '89, I could feel them drag/scrape just a little on the inside of the valve guide. I haven't put them back in yet, but will probably just debur and clean them up, then then give them a try with new seals.

    Can you post a photo of the offending valve?
  19. Caperodder

    Caperodder Adventurer

    Joined:
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    Oddometer:
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    I encountered just that. I noticed when pulling the valve out, that it did not want to go through the guide. Had a small slat stone, and that took care of it. Was only on one of the valves. Here is a pic of mine. No additional groove.

    IMG_6447.jpg
  20. Caperodder

    Caperodder Adventurer

    Joined:
    Jan 14, 2014
    Oddometer:
    95
    And...Thanks for the paint info!
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