Yamaha RT2 piston clearance. Anyone with a manual?

Discussion in '2 smokers' started by TheRadBaron, Aug 11, 2013.

  1. TheRadBaron

    TheRadBaron Been here awhile

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    I recently scored a nice, original '72 Yamaha RT2 enduro. It just needs a rebore and piston, but I can't find the piston clearance spec anywhere online. I'll buy a shop manual for the bike soon, but until then I'd really like to be able to tell my machinist what clearance it needs.
    Does anyone here have a manual for an RT2 or RT3 that could look it up? I could use head bolt torques, too. Thanks a lot.
    If anyone has a scanned copy of a manual available, that would be even better.
    #1
  2. Twin-shocker

    Twin-shocker Long timer

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    Any good machine shop will know the correct clearance for your bike. If you choose to use a Wiseco piston the clearance is marked on the box.
    #2
  3. anotherguy

    anotherguy Long timer

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    Generally cast pistons are .002-.003",forged .003-.0045".
    #3
  4. TheRadBaron

    TheRadBaron Been here awhile

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    Thanks for the responses. I agree that any good machine shop will know what clearance a given type of piston generally should have for a given bore size, but most machine shops don't have a manual for every motor ever made. I always like to look at a manual for the bike I'm working on since the engineers that designed that specific motor know what clearance works best. It is uncommon, but sometimes a clearance is specified that's different than the "general rule".
    #4
  5. Twin-shocker

    Twin-shocker Long timer

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    Why not get a manual then?
    #5
  6. TheRadBaron

    TheRadBaron Been here awhile

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    Well, just like I said in my original post, I am going to get a manual. My machinist has my cylinder and piston right now, though. I thought that while I was waiting for my manual to arrive, someone in the vast ADV community might have a manual and could look up a spec for me.
    #6
  7. TheRadBaron

    TheRadBaron Been here awhile

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    Well, it turns out that I had a manual all along. I found one in my stack of manuals while looking for a different one.
    The clearance isn't listed for the RT2 or RT3, but the RT1 is given as 0.0022-0.0024". The -2 and -3 have the same bore and stroke, the only difference that I know of being the reed valves on the later models.
    #7
  8. KayAitch

    KayAitch Adventurer

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    Good job RadBaron.

    Don't mind Twin-shocker, I guess he needs to work on his reading comprehension and maybe his attitude. :evil
    #8
  9. TheRadBaron

    TheRadBaron Been here awhile

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    Thanks. I'm getting that impression from every other thread that he posts in.
    #9
  10. motocrossross

    motocrossross Been here awhile Supporter

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    Lets see some pictures. The '72 was silver, right?
    #10