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Cylinder Head Bolt Torque for '82 XS400R

Discussion in 'The Garage' started by robindean, Dec 20, 2011.

  1. robindean

    robindean XS400 Addict

    I've never done this before.

    What I know:

    - I need a torque wrench (got one)
    - I should adjust each in moderation in constant succession, so as not to warp or shatter anything.

    What I don't know or can't seem to find:

    - How many bolts are there for my bike?
    - Where are they located?
    - How many ft-lbs of torque am I supposed to apply?

    My PDF manual provides a lot of information but searching for this kind of info is proving difficult.
  2. bcware

    bcware Well-read Top Contributor

    If you're going to attempt this job with no previous experience you must read the entire top end rebuild section in the manual. Do not skip or skim anything. Sometimes important information is spread out throughout the chapter.

    If you have the manual in front of you there is no reason to make a post asking someone else to read it for you. I don't want to sound too harsh, but you do this a lot and it worries me that you're going to make a costly mistake.
  3. HoughMade

    HoughMade XS400 Guru Top Contributor

    When I torqued my head down due to some oil seepage, I did it with the manual open in front of me which had an illustration of the sequence and the torque values....if I did it again, I would do the same.
  4. robindean

    robindean XS400 Addict

    I see, in the manual, the different orders in which everything needs to take place. I have no intention of "skimming". The details will be covered. It's the PHOTOS that are often tough to work with. We're talking about an engine here, so ...

    Unfortunately I do NOT have a PHYSICAL copy of the manual. I only have a blurry PDF that was never converted with a text scanner. I'm thinking it's time for me to search eBay. Having a physical copy would be really, really useful. Hell, I'd read that before porn.

    Now, if you'll excuse me BC, I have to go find some duct tape and Elmer's glue. My assumption is that the more I apply, the better my bike will run. I'd ask a forum about this but I feel that because the PDF manual looks to be made mostly out of the same materials, they must suggesting that I use that for my bike as well. At least, that's what I got from it while was skimming through it.

    Now, to skim through my book on heart surgery ... wears my cat? :D
  5. drewpy

    drewpy Excess twin Top Contributor

    I have 4 manuals on the sohc 400. 1 genuine yam one, 2 haynes ( 1 for bedtime and 1 for workshop) and a clymer (rubbish). I also have pdf's too

    Oh, and a parts book

    you can never have enough info!
  6. robindean

    robindean XS400 Addict

    Agreed, Drewpy :)

    That's why I keep posting in this forum.
  7. robindean

    robindean XS400 Addict

    As I see it, pages 22 and 23 of "82_service_manual_chapter3_engine_overhaul_part3.pdf" provide the information needed for me to check/set the cylinder head bolt torque. I'd like to do this as a simple maintenance activity without having to remove the engine from the frame.

    I'm aware of the dangers and sensitivities that could leave me with a warped head (and mind lol) so I'm not going to do anything until I'm confident about what I'm doing.

    So, I'll start with this question: Can I properly torque the cylinder head without removing the engine?

    If not, do tell. However, if so ...

    On page 23 I see three photos (from two images) which represent two patterns. I've read the given tech specs but am wondering the following and in need of advice:

    1) Do I address the numeric order of the pattern based on a COMBINATION of both photos? Namely, start with what's on the right and then hit what's on the left?

    2) If #1 is true, I'm confused as to why there is a numeric "1" pointing at two bolts in the left photo ... to the right within it.

    I'm learning here and wish to avoid harming my ride. Thanks for you patience as I ask these questions.
  8. robindean

    robindean XS400 Addict

    Bumpity bumpity bump!
  9. drewpy

    drewpy Excess twin Top Contributor

    should be able to torque the head down with the engiine in the frame.

    I don't have access to that manual mainly because i don't have that model.
    Normally the torque sequence is a criss cross pattern starting from the outside working inwards
  10. FUBAR

    FUBAR XS400 Addict

    pretty sure its 24 ft/lbs for the middle acron heads and 8 ftlbsfor the 2 outers, and you just start in the middle and work out in a star pattern.
  11. robindean

    robindean XS400 Addict

    You're both right and I've managed to get that far with said info.

    My problem is that the diagram in my manual is showing THREE number 1 starting points.

    The manual is available here: http://www.xs400.com/forum/showthread.php?t=4503

    If you go to that page and download "82_service_manual_chapter3_engine_overhaul_part3.pdf", then set your PDF reader to page 23, you'll see the three images I'm locked into.

    I see the pattern and want to get it right. Why are there three number 1 starting points? Do I follow that pattern in order?

    I've been after this information for a while am finding it difficult to attain. I feel as if I'm close but just need that last bit of info to complete the circuit of understanding.
  12. FUBAR

    FUBAR XS400 Addict

    have you ever torqued lug nuts on a wheel?

    the nuts are in this pattern - : : : : -

    snung each nut down finger tight and the start tourquing.

    start with one of the middle four nuts and work in an X pattern even outward to the edges of the engine. its not rocket science man
  13. lhaolpa

    lhaolpa XS400 Junkie

    Also,it's important to torque in 3-4 stages,starting with about 5lbs,then gradually progress until final torque is reached.I always re-torque after a while running,but some manufacturers say nothing about that.After final torque,check to make sure all fasteners[nuts,bolts]are properly torqued. lha
  14. robindean

    robindean XS400 Addict

    It's rocket science to me. I've never done this. If I warp the head, it's over. My question is thought out and arranged so that the information is accessible to anyone who wants to help me get it right, which is what this section of the forum is all about.

    I want to do this properly, using the manual. I think it would've been a mistake for me to just remove the top cover and start cranking at things because "hey, they're just bolts" ... which is why I've provided the exact manual file location as well as the page number with the diagram.

    I see the info. I'm confused by one detail. I'd like to know more about that one detail.

    @lhaolpa - Thank you. I'll work in more stages. That sounds more balanced and easier on the tension. I appreciate the info.


    Before answering the question, you might want to download the file and set your PDF viewer to page to 23 as I mentioned in my previous post.
  15. lhaolpa

    lhaolpa XS400 Junkie

    You can start with whichever inside nut/bolt you want as long as you follow the pattern shown on the diagrams. Just finger tighten first,then start with a low torque first,like 1/4 of the #,then 1/2,then 3/4,etc. lha
  16. robindean

    robindean XS400 Addict

    I see now. There is only one "1" ... the other two "1s" which are double numbered are simply labeled in reference to them having copper washers. I couldn't make sense of that even after repeat looks.

    So now, if I'm to do multiple stages ... let's say three ... then I need to divide the total torque by three and then torque result * 1, then result * 2, then final torque (result * 3).

    Got it. Wish me luck.
  17. robindean

    robindean XS400 Addict

    So, a day or so ago I decide that I'm ready to give this a go. Then I notice something ... the engine on my bike isn't supported from below, as far as I can tell. It seems to be "hanging" from the frame at three, maybe four locations.

    Assuming this is the case, I see no way to check/adjust the bolt torque without first removing the engine.

    Can anyone with a similar bike confirm or deny this?
  18. FUBAR

    FUBAR XS400 Addict

    thats probably cause your bikes a seca, its got no bottom portion of frame under the engine, the engine is part of the structure. shouldnt have to take it out of the frame, just take the carbs off give yourself more room take the tank off and remove the valve cover on the top of the engine.
  19. lhaolpa

    lhaolpa XS400 Junkie

    Actually 1/4 at a time would take 4 adjustments[passes]to reach final torque,but if it's better for you,use 3 passes.I'm use to torquing head bolts to 85 ft/lbs. lha

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