Results 1 to 14 of 14

Thread: Tell Me About This Piston

  1. #1
    DEDGCOMB141129
    Guest

    Tell Me About This Piston

    Pulled the left jug today.....
    65' R60/2...54K....
    Miles of grime...no wrench marks...I think it's the first time she's got nekkid....
    ...ran great with low compression for 44 years...and now we can see der piston......
    ...any thoughts on how good...or bad...this bike runs...on what ya see?.....
    Attached Images Attached Images

  2. #2
    Rally Rat
    Join Date
    Sep 2007
    Posts
    1,248

    What A Piston

    What was the ratio of oil to fuel consumed?

  3. #3
    Administrator 20774's Avatar
    Join Date
    Sep 2005
    Location
    San Antonio, TX
    Posts
    13,042
    From my limited experience, I don't see anything hugely wrong there. Probably your rings gaps had gotten pretty big and let some of the compression by, hence the discoloration on the sides. Piston crown...seems like they all look somewhat like that after a good number of milesl

    You'll need to measure the ovality/dimensions of the cylinder and pistons to see where you're at considering stock sizes. You're probably need a rebore to the next size which also means new pistons and rings. There's a company, Bore-Tech, which does a good job at boring cylinders and then putting a carbide coating on the walls. It goes a long way to reducing wear on the walls.

    Continue the cleanup and go from there.
    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!

  4. #4
    Benchwrenching PGlaves's Avatar
    Join Date
    Oct 2003
    Location
    "Big Bend" TX
    Posts
    8,652
    My suspicion is an out-of-round cylinder - based on the pattern that looks like combustion gasses cooking the side of the piston below the rings near the wrist pin. Carefully check the cylinder.
    Paul Glaves - "Big Bend", Texas U.S.A
    "The greatest challenge to any thinker is stating the problem in a way that will allow a solution." - Bertrand Russell
    http://www.bigbend.net/users/glaves

  5. #5
    Registered User
    Join Date
    Jun 2003
    Location
    WC Indiana
    Posts
    843
    What was the oil like when you changed it? Filter always full of sludge? Lot of crankcase back pressure?

  6. #6
    Mars needs women! 35634's Avatar
    Join Date
    Apr 2008
    Location
    SW Ohio
    Posts
    2,031
    Probably the wrong voltage brake light. That can cause the alternator to backfire,
    forcing angry electrons out the wrist pins. Filling the tires with nitrogen can minimize
    the problem, but the only real cure is to buy a 1984 F-150.

  7. #7
    DEDGCOMB141129
    Guest

    Please delete this thread

    Dear Administrator,
    It appears...I've made a mistake...
    ...buying the bike....thinkin' I could keep her going....hoping that some helpful fellows would impart some hard learned knowledge and experience...
    ...and parting with another $40 to join this club.....
    I can spend a lot more than that...to get less asinine comments to my questions...
    ...I assure you...y'all won't be bothered by any posts from me again....
    Please delete this thread...as it seems to not be suitable....
    Thanks for All Your Help...

  8. #8
    Still Wondering mika's Avatar
    Join Date
    Aug 2004
    Location
    Fly Over Land
    Posts
    10,539
    Quote Originally Posted by DEDGCOMB141129 View Post
    Pulled the left jug today.....
    65' R60/2...54K....
    Miles of grime...no wrench marks...I think it's the first time she's got nekkid....
    ...ran great with low compression for 44 years...and now we can see der piston......
    ...any thoughts on how good...or bad...this bike runs...on what ya see?.....
    Quote Originally Posted by PGlaves View Post
    My suspicion is an out-of-round cylinder - based on the pattern that looks like combustion gasses cooking the side of the piston below the rings near the wrist pin. Carefully check the cylinder.
    I would think Paul hit the mark with the problem being an out of round cylinder sleeve. What appears to be carbon build-up below the rings and above the wrist pin could result in the bike being ÔÇÿself healingÔÇÖ and running reasonably well before the tear down. The carbon builds up overtime as the uneven cylinder wear developed over time.

    Before you give up on the forum all together I hope you tell us if Paul was right.

  9. #9
    Rally Rat
    Join Date
    Sep 2007
    Posts
    1,248

    This Piston

    I'm sorry you were offended by our smart-alecky replies. You have to have a well developed sense of humor to enjoy these forums, as well as a thick skin.

    Your piston has a blowby problem. I can see that oil ring is worn, so the other rings probably are too. The next step is to see whether you need to replace the piston and rebore the cylinder, or simply do a ring replacement. Let us know how much more you need to learn.

  10. #10
    DEDGCOMB141129
    Guest
    ...Back in my Day,
    We just didn't beat up the new kid...as soon as he got there....
    We'd get him to join the Hockey Team...then beat the Hell out of him!!!...
    ...It was Sport.....Team ......
    ...If I was that thinned skin...I'd be riding a Sporster!.....

  11. #11
    God? What god? roborider's Avatar
    Join Date
    May 2007
    Location
    Raleigh, NC
    Posts
    2,061
    Don't be over sensitive. The posts were funny; I laughed. Some posts are meant for the readers' amusement and not meant to be taken seriously. Have fun.
    Rob C. , Raleigh, NC
    '10 R12RT, R90/6
    2007 CBR600RR & 09 V-Star
    Suzuki DR 350

  12. #12
    Cannonball Rider #52 darrylri's Avatar
    Join Date
    Oct 2003
    Location
    Surf City, USA (Santa Cruz, CA)
    Posts
    4,530
    [mod hat=on]
    Can we talk about the vintage stuff in the vintage area? The campfire stuff goes over in the campfire area. Thanks.
    [mod hat=off]
    --Darryl Richman, forum liaison
    http://darryl.crafty-fox.com

  13. #13
    advrider.com
    Join Date
    Oct 2005
    Posts
    3,192
    So, what are your plans for it? Have you measured anything? Are you putting new rings in?

  14. #14
    Registered User RINTY's Avatar
    Join Date
    Nov 2005
    Location
    Calgary, Alberta
    Posts
    4,302

    piston

    Dedgcomb:

    Hope you stick around. They're actually a pretty mild bunch around here.

    And they'll crack jokes on anybody's thread; keeps them going through the winter.
    Rinty

    "When you don't know where you're going, any road will get you there."

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •