The XR400 Thread

Discussion in 'Thumpers' started by Hayduke, Jan 16, 2008.

  1. Jeff B

    Jeff B Socially Awkward

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    I have found that "Wet Humping" is the best method for adding fluids to the bike. :nod
  2. G600

    G600 Been here awhile

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  3. arghhh

    arghhh Adventurer

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    I see people buy a CRF450 cam chain (part number 14401-MEB-671) instead of another XR cam chain, but I haven't seen any long term updates. I assume all is well with using the CRF450 cam chain in the long run?
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  4. dlock5

    dlock5 Been here awhile

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    Yes, its better and actually cheaper .
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  5. cmbthumper

    cmbthumper Been here awhile

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    Never read that and though I'm a ways out from replacing I will be interested to read replies.
  6. Stretch67

    Stretch67 Mad Scientist Supporter

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  7. shinyribs

    shinyribs Thumpers for life

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    I also run that chain. Fits perfect and will hold up longer in the long term, actually.
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  8. Johnnyboxer

    Johnnyboxer Long timer

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    2003 Honda XR400R - how to improve the suspension?

    In particular the forks, all standard are present

    I am 105 kgs, so I guess the forks could do with heavier springs, for a start and/or heavier weight oil, for starters

    I was thinking Race Tech Valves too - maybe

    I don't want to lose the 'plushness' in favour of harder suspension as I am only trairiding at 30 mph or less, not racing

    At the rear, I have changed the shock for a WP version and this has improved it no end, much more 'plushness' and a resistance to bottoming out

    Any thoughts or tips.....................what have you done?
  9. shinyribs

    shinyribs Thumpers for life

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    I thought the stock forks were harsh, so I worked on mine to gain a plush ride. Since you mention a plush ride and fear getting a firm suspension, I think your first step is deciding what you want when you say "improve suspension".

    If you are happy with the current plushness while trail riding, but are experiencing lots of bottoming, just re-spring and see where you are after that.

    If you are after suspension work just to chase the idea of "upgrading", every rider and terrain is different- there's no right or wrong on a suspension setup.
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  10. arghhh

    arghhh Adventurer

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    You guys not had any problems with worn cam chain guides or anything? I'm just wondering since the CRF chain is wider, does it sit on those ridges of the cam chain guide that normally "hold" the stock cam chain in position. Basically filing them off and creating some debris?
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  11. Johnnyboxer

    Johnnyboxer Long timer

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    Thanks, I want plushness overall
    How did you improve the harshness of the forks on yours, what did you do?
  12. Stretch67

    Stretch67 Mad Scientist Supporter

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    Sounds plausible, but I've seen no adverse effects.
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  13. shinyribs

    shinyribs Thumpers for life

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    It's kind of long to explain, but it's in this thread somewhere. Basically, after experimenting, I decided the stock compression valve was unable to flow enough oil ( the shims weren't the restriction), so I modified the valve for more flow. Really wasn't a very complicated process.

    https://advrider.com/f/threads/the-xr400-thread.302523/page-654
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  14. shinyribs

    shinyribs Thumpers for life

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    No issues. The CRF chain is is the same profile, so it doesn't dig in to the guide in any unusual way. The CRF chain is just a plate or two wider, so it's stronger stronger.
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  15. Luke

    Luke GPoET&P

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    IMO the crf chain is too wide. It can move side to side on the sprockets and is wider then the groove in the guides. I ran it for a little while, then went back to a stock chain at the next rebuild.
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  16. shinyribs

    shinyribs Thumpers for life

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    When I first read about guys using the CRF chains I was curious if the XR chain guides would accommodate it, but when I fitted mine up the edges on the guides were plenty wide to take the wider chain without and clearance issues.

    As far as moving on the sprocket, I'm not sure how that would happen. But, it's been 3 years since I rebuilt my engine and installed the CRF chain, so there could be something I'm not remembering.
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  17. Jeff B

    Jeff B Socially Awkward

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    If I could of acquired a matching set of sprockets [also wider] I would of used the wider CRF chain. So I saw now advantage since it wouldn't change the contact area at all.

    About the only effective change would of been increased revolving mass.
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  18. shinyribs

    shinyribs Thumpers for life

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    Very rarely will you see a cam chain eat in to the teeth of the sprocket. You never really see the teeth of the chain worn away either. What we do see cam chains do is "stretch". Whether that stretch is pin wear or actually plate stretching, more links helps to offset that wear.

    Are stock chains problematic? Not really.

    Do CRF chains cause problems? No, and it was a third of the cost when I was buying a chain.

    Depending on your point of view, budget, etc I don't think your can go wrong with either choice.
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  19. Luke

    Luke GPoET&P

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    It's got room to walk a few mm side to side. There's nothing to force it but it seemed like it could wander on its own. If it sat on one side it would likely wear in slightly and stay there.

    That's just my impression, though. When I replaced the chain it seemed fine, the rest of the motor was trashed. So it may just be my imagination.
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  20. shinyribs

    shinyribs Thumpers for life

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    Yeah, I'm not sure either since it's been so long so I looked at one. But generally, the teeth of the sprocket go up in to the chain, which keeps the chain from wandering off the sprocket. I don't think these engines are any different. The cam chain tensioner guides just runs the chain to provide tension and a keep chain slap down, they don't offer any lateral guidance.
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