In loving memory of Kenis D. Keathley 6/4/81 - 3/27/22 Loving father, husband, brother, friend and firewood hoarder Rest in peace, Dexterday

stuck piston rings.....what's the secret?

Discussion in 'Chainsaws and Power Equipment' started by Scotty Overkill, Oct 20, 2016.

  1. Redfin

    Redfin

    Joined:
    Mar 1, 2015
    Messages:
    922
    Likes Received:
    4,262
    Location:
    central Pa
    Success. Another dip in the ultra tank to clean the lands. IMG_1398.JPG
     
  2. brenndatomu

    brenndatomu

    Joined:
    May 29, 2015
    Messages:
    22,081
    Likes Received:
    139,853
    Location:
    NE Ohio
    Sounds like a pretty good day, eh? ;) :rofl: :lol:
     
  3. Redfin

    Redfin

    Joined:
    Mar 1, 2015
    Messages:
    922
    Likes Received:
    4,262
    Location:
    central Pa
    You funny guy Tim, funny guy.
     
  4. Scotty Overkill

    Scotty Overkill Administrator

    Joined:
    Oct 1, 2013
    Messages:
    9,480
    Likes Received:
    62,916
    Location:
    Central PA
    That's awesome, Redfin you da man! My NOS rings arrived yesterday while we were at the GTG, still in the original box.....

    Couple more parts to arrive and I'll be putting this little twin cylinder engine back together!

    Next crisis.....gotta find someone who can make me diaphragms for the carburetor....

    :headbang::headbang::headbang:

    Anybody know of anyone? I hear-tell there's a guy that makes custom kits.......now I gotta find out who it is.....:picard:
     
    NortheastAl and clemsonfor like this.
  5. clemsonfor

    clemsonfor

    Joined:
    Oct 3, 2013
    Messages:
    15,996
    Likes Received:
    37,472
    Location:
    Greenwood county SC
    That's awsome. those ultra sonic cleaners must be amazing.

    OK I'll bite. both those pistons out of the same saw??? I have to Google this thing now!
     
  6. TurboDiesel

    TurboDiesel

    Joined:
    Nov 22, 2013
    Messages:
    16,146
    Likes Received:
    96,676
    Location:
    Hollidaysburg Pa
    :dex:
    Long before there were turbos and superchargers...:yes:
     
    Scotty Overkill and NortheastAl like this.
  7. clemsonfor

    clemsonfor

    Joined:
    Oct 3, 2013
    Messages:
    15,996
    Likes Received:
    37,472
    Location:
    Greenwood county SC
    I googled it but still can't figure out where the second one goes ? and the brief write up on vintage chainsaw collector site didn't explain the design well enough for me
     
    NortheastAl and Horkn like this.
  8. Horkn

    Horkn

    Joined:
    Dec 17, 2014
    Messages:
    27,726
    Likes Received:
    155,630
    Location:
    SE Wisconsin

    Where's the "shave"?

    Sh... Shave and Shower
     
  9. Horkn

    Horkn

    Joined:
    Dec 17, 2014
    Messages:
    27,726
    Likes Received:
    155,630
    Location:
    SE Wisconsin
    Turbos and superchargers were invented in 1905. The internal combustion engine was invented 100 years before that.

    I've never seen a chainsaw like this though.

    From what I see, the secondary piston, is mostly for balancing of the bigger piston.
     
  10. bobdog2o02

    bobdog2o02

    Joined:
    Nov 19, 2015
    Messages:
    3,005
    Likes Received:
    10,406
    Location:
    Drury Lane, PA
    My guess is it evens out the crank case pulses....?
     
  11. Horkn

    Horkn

    Joined:
    Dec 17, 2014
    Messages:
    27,726
    Likes Received:
    155,630
    Location:
    SE Wisconsin
    Yes, that's all I can see. Counterweights or counter balancers are the traditional way to tame that.
     
  12. concretegrazer

    concretegrazer

    Joined:
    Oct 3, 2013
    Messages:
    4,429
    Likes Received:
    12,447
    Location:
    Southwest MO
    Correct. BP-1 for balence piston.

    Hope you have her running soon Scotty!
     
  13. Scotty Overkill

    Scotty Overkill Administrator

    Joined:
    Oct 1, 2013
    Messages:
    9,480
    Likes Received:
    62,916
    Location:
    Central PA
    Yep, BP stands for "balanced piston". They really were a revolutionary design way ahead of their time.

    That Balance Piston (or "bump" piston as it can be referred to) also acts kinda like a supercharger and intake valve. It "inhales" the fuel mix and compresses it.....

    Once I get something figured out on the carburetor (need to get a custom kit made), there's a chance I could possibly have it running by the end of November......

    I'm saving all my pics and such for a post once I get close to the end....so far I have NOS rings, NOS air filter, new crank bearings and also new crank/gear case seals on the way.
     
  14. Redfin

    Redfin

    Joined:
    Mar 1, 2015
    Messages:
    922
    Likes Received:
    4,262
    Location:
    central Pa
  15. Scotty Overkill

    Scotty Overkill Administrator

    Joined:
    Oct 1, 2013
    Messages:
    9,480
    Likes Received:
    62,916
    Location:
    Central PA
  16. clemsonfor

    clemsonfor

    Joined:
    Oct 3, 2013
    Messages:
    15,996
    Likes Received:
    37,472
    Location:
    Greenwood county SC
    So it indirectly drives he bar though some offset driveline
     
    NortheastAl likes this.
  17. Scotty Overkill

    Scotty Overkill Administrator

    Joined:
    Oct 1, 2013
    Messages:
    9,480
    Likes Received:
    62,916
    Location:
    Central PA
    Gear drive
     
  18. Horkn

    Horkn

    Joined:
    Dec 17, 2014
    Messages:
    27,726
    Likes Received:
    155,630
    Location:
    SE Wisconsin
    That is cool. I read that it automatically sharpens its chain too.

    Neat stuff. Now why can't they redo this saw with new tech to improve upon the bp1's features?
     
  19. Scotty Overkill

    Scotty Overkill Administrator

    Joined:
    Oct 1, 2013
    Messages:
    9,480
    Likes Received:
    62,916
    Location:
    Central PA
    I've pondered the same question.......it'd be cool to see a re-do with modern electronics....
     
    clemsonfor and Horkn like this.
  20. Scotty Overkill

    Scotty Overkill Administrator

    Joined:
    Oct 1, 2013
    Messages:
    9,480
    Likes Received:
    62,916
    Location:
    Central PA
    Here's a short video clem, breaks it down for ya so you can kinda see how it works.