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Thread: Loosen,Retorque,Loosen Retorque.........

  1. #1
    Arctic Art
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    Cool Loosen,Retorque,Loosen Retorque.........

    So,what's with the loosen and retorque of the heads at every valve adj. Seems to me like it would break the head and cyl. seal and promote leaks,over stress threads and promote studs backing out.In other motor work,it's torque then retorque that's it.I can see checking the torque,but why loosen. I just replaced all the head/cyl seals in my 1983 R100,20K.No leaks when I got it,but did the loosen/retorque thing and the cyl base started leaking. I used the proscribed sealent in the proscribed manner to reassemble.By the by there was no sealent on the cyl base and the cyl O ring gasket was white.

  2. #2
    Administrator 20774's Avatar
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    +1...I agree with you and don't loosen and retorque myself. Maybe once in a great while. I might put the wrench on it and see if can take the 25 ft-lbs statically...if so, then I figure nothings' loosened up. But during the break-in process, I might consider doing it because things are changing. But once set, I'd leave it along.
    Kurt -- Forum Administrator ---> Resources and Links Thread <---
    '78 R100/7 & '69 R69S & '52 R25/2
    mine-ineye-deatheah-pielayah-jooa-kalayus. oolah-minane-hay-meeriah-kal-oyus-algay-a-thaykin', buddy!

  3. #3
    doktortim
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    One nut at a time, back off 1/8 turn then back to spec. I don't touch the upper and lower nuts, only the rocker blocks with the long studs. And I do this only once every 3 or 4 valve adjustments.

    If you have to loosen both nuts on one rocker to reset endplay, do each set separately, always leaving 4 nuts at full torque. You will not have head or base seal issues this way.

  4. #4
    Registered User 88bmwjeff's Avatar
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    The first thing I do is check the valves for clearance. If everything's OK, I leave it be. I've heard several "gurus" say they do the same. I don't think there's a reason to retorque the heads if everything is OK.
    Jeff in W.C.
    1988 R100 RT (the other woman)
    "I got my motorcycle jacket but I'm walking all the time." Joe Strummer

  5. #5
    IBA #44567 Ken F's Avatar
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    Out of curiosity, What is the required torque for the rocker blocks?

    I know that initally, it is a certain amount plus 90 degrees IIRC, but to retorque is there a set amount after the studs have been stretched?

    Ken
    IBA #44567
    "Two things are infinite: the universe and human stupidity; and I'm not sure about the the universe."
    -Albert Eienstein

  6. #6
    Administrator 20774's Avatar
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    Airhead rocker/head bolt torque doesn't have have any degree measurement associated with them...I think that is an Oilhead or K-bike requirement. It's pretty simple for our bikes. The end value is 25 ft-lbs with a know good torque wrench. You want one where the 25 ft-lbs is not at the low end or the high end of the scale to ensure good accuracy. If putting a head on from scratch, the 6 nuts should be run in to finger tight. Try to tighten then in a criss-cross pattern equal amounts...you're pulling everything down evenly. When there's reasonable tightness, then begin watching the torque. Use steps like 15, 20, 25 or 18, 22, 25. You want to take the reading while the torque wrench is moving...it's a sliding torque value.

    If doing this with bolts already torqued, one at a time, back a bolt off maybe 1/4 turn, then retorque to the 25 value while the wrench is moving. Then in criss-cross fashion, loosen and retighten the remaining bolts.
    Kurt -- Forum Administrator ---> Resources and Links Thread <---
    '78 R100/7 & '69 R69S & '52 R25/2
    mine-ineye-deatheah-pielayah-jooa-kalayus. oolah-minane-hay-meeriah-kal-oyus-algay-a-thaykin', buddy!

  7. #7
    IBA #44567 Ken F's Avatar
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    Yes, thanks for the reply Kurt. I was speaking of an oilhead, not realizing that this was from the Airhead forum. Duh.

    Nonetheless...I appreciate your reply.

    Ken
    IBA #44567
    "Two things are infinite: the universe and human stupidity; and I'm not sure about the the universe."
    -Albert Eienstein

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