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Thread: piston rings

  1. #1
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    piston rings

    I am replacing gaskets on my 07 lightning, I was jacking with the circlip on the wrist pin and the jug moved an the bottom two piston rings popped out. There is no way to know if they turned but my guess is that they prob did. Can I stuff them back in or do I have to hone and re ring?

    Thanks

  2. #2
    Senior Member Barrett's Avatar
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    Many variables here. If the cylinder liner gives little to no indication of having been hot-spotted...and the rings still appear and feel as if they have decent tensile strength...and the mileage is reasonable for a 2007...and it had good compression and low oil consumption before you tore into it....then re-use the rings. If the cylinder is removed it would be an acceptable idea and procedure to lightly run a simple brush hone with cutting fluid, thru the bore a few times. Will clean it up and won't remove original hatch marks if done sensibly. Below is both how the factory wants the rings oriented in relationship to the wrist pin bore of the piston...and how I explain it. Read...digest...follow precisely when reinstalling rings onto their lands.

    Locate the piston so that the wristpin is in a hortizontal plane. Position the top compression ring gap at 45 degrees to the wristpin hortizontal centerline. It should be in the upper right hand "corner". Now position the second ring's gap 180 degrees from the the first ring. That would put that gap in the lower left "corner". For the first oil ring scraper install that ring so the gap is between the the first two rings. It can be in either the lower right hand "corner" or the upper left hand "corner". Now install the second oil scraper 180 degress or opposite the first. That would put that ring in the last "corner". Do NOT have any gaps located on the thrust line of the piston or it's neutral axis. It also allows for all the gaps on adjacent top and second rings to be located 180 degrees apart.

    This is pretty much how the SM outlines the procedure but the above in simpler and more easily understood.
    Last edited by Barrett; 06-15-2022 at 10:54 AM.

  3. #3
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    Quote Originally Posted by Barrett View Post
    Many variables here. If the cylinder liner gives little to no indication of having been hot-spotted...and the rings still appear and feel as if they have decent tensile strength...and the mileage is reasonable for a 2007...and it had good compression and low oil consumption before you tore into it....then re-use the rings. If the cylinder is removed it would be an acceptable idea and procedure to lightly run a simple ball hone with cutting fluid, thru the bore a few times. Will clean it up and won't remove original hatch marks if done sensibly. Below is both how the factory wants the rings oriented in relationship to the wrist pin bore of the piston...and how I explain it. Read...digest...follow precisely when reinstalling rings onto their lands.

    Locate the piston so that the wristpin is in a hortizontal plane. Position the top compression ring gap at 45 degrees to the wristpin hortizontal centerline. It should be in the upper right hand "corner". Now position the second ring's gap 180 degrees from the the first ring. That would put that gap in the lower left "corner". For the first oil ring scraper install that ring so the gap is between the the first two rings. It can be in either the lower right hand "corner" or the upper left hand "corner". Now install the second oil scraper 180 degress or opposite the first. That would put that ring in the last "corner". Do NOT have any gaps located on the thrust line of the piston or it's neutral axis. It also allows for all the gaps on adjacent top and second rings to be located 180 degrees apart.

    This is pretty much how the SM outlines the procedure but the above in simpler and more easily understood.
    Thanks. The SM does indeed show the ring positions like you said, but the SM basically says to hone and replace rings, leaving no option to use the OEM rings. The bore looks fine, and I realize we're talking microscopic here but if there is no problem using the OEM rings, I'd opt for that. Though if many of you here on the forum say 'I've tried that and was burning oil like crazy,' I'll opt to re ring.

    This is the first motorcycle motor I've dug into. I've honed and put new rings in piston air compressors before, but never a cycle motor.

    I appreciate the advice.

  4. #4
    Senior Member Cooter's Avatar
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    Meh, run 'em.

    The SM instructions align with what our esteemed Barrett laid out for you and are for assembly, they will rotate when in use anyway so...

    Put them back in carefully though, jamming them in there and damaging the sealing edge is the oil problem, not their position.

  5. #5
    Senior Member 34nineteen's Avatar
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    I use a pocket clip of a ball point pen cap, or a popsicle stick to coax the rings back into their grooves.

    https://www.youtube.com/watch?v=sVzVwb_LUBo

    Scroll ahead to about 9:10 and Hammer Dan will tell you how its done.

  6. #6
    Senior Member Cooter's Avatar
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    Whats a ball point pen?











    Boomer.

  7. #7
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    Quote Originally Posted by Cooter View Post
    Whats a ball point pen?











    Boomer.
    You tell the old guy Cooter

    Oh yeah we only missed being Boomers by two years

  8. #8
    Senior Member 34nineteen's Avatar
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    Quote Originally Posted by Cooter View Post
    Whats a ball point pen?
    You're a ball point pen.



    Quote Originally Posted by Cooter View Post
    Boomer.

    Here's Boomer
    TV Series
    19801982
    30m
    The adventures of Boomer, a stray dog who travels the country helping those in trouble.


    Kind of sounds like you.

  9. #9
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    Thanks everyone... Bit the bullet and honed and am installing new rings.

  10. #10
    Senior Member 34nineteen's Avatar
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    Quote Originally Posted by BuddyB View Post
    Thanks everyone... Bit the bullet and honed and am installing new rings.
    Make sure the ring gap is correct on the new rings. There isnt a whole lot of room for error, as its an air cooled motor and things will expand more than a water cooled motor, and be sure to measure at a few different spots in the bore. A pinched ring will bring you back to where you are at now, but worse. Almost all that I have had to deal with have needed some clearancing done.

    PS. In case Cooter offers to help and bring his ring file, keep in mind that the amount of beer he drinks will far exceed the price of the ring file.


    Last edited by 34nineteen; 06-16-2022 at 05:50 PM.

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