Stoker motor

Discussion in '2 Stroke Bicycle Engines & Kits' started by doomedgame, Jan 22, 2018.

  1. doomedgame

    doomedgame Member

    Joined:
    Jan 26, 2017
    Messages:
    151
    Likes Received:
    9
    Jug has to be spaced up to match. The larger bore and larger stroke will increase crankcase compression. Going to slip fit the crank and clutch so I can easily brake it down if I want to stuff the case later.
     
  2. cannonball2

    cannonball2 Active Member

    Joined:
    Oct 28, 2010
    Messages:
    3,558
    Likes Received:
    22
    Guys at MZ are pretty sharp. Good people to deal with. Having a lined bore will be a great thing!
    Is this 4mm on a 38 or 40mm crank? Other words what is the total stroke?

    The Stihl conversion I'm attempting (same as Zeda MS) is designed for a 40mm stroke. The unknown at this point is the piston pin height. Still waiting on the parts. What you are doing is similar enough to be of help to me on my project. Will follow closely.
    Interestingly you can button the ends of the piston pin to also raise primary compression.
     
    #22 cannonball2, Jan 31, 2018
    Last edited: Jan 31, 2018
  3. doomedgame

    doomedgame Member

    Joined:
    Jan 26, 2017
    Messages:
    151
    Likes Received:
    9
    Look like the pins in the same spot and the difference is taken up at the base gasket makes sense as the exhaust duration is low in these motors

    Left is the 48mm right is the stock short rod motor
    It look like a zeda kit not my video
     

    Attached Files:

    #23 doomedgame, Jan 31, 2018
    Last edited: Feb 1, 2018
  4. doomedgame

    doomedgame Member

    Joined:
    Jan 26, 2017
    Messages:
    151
    Likes Received:
    9
    Bearings (6202 RS) should be here today working on finishing the intake opening the plate from 14mm to about 1 inch
     
    #24 doomedgame, Feb 2, 2018
    Last edited: Feb 8, 2018
  5. doomedgame

    doomedgame Member

    Joined:
    Jan 26, 2017
    Messages:
    151
    Likes Received:
    9
    Little bit more done crank bearings are slip fit almost ready to put the bottom end back together.
     
  6. doomedgame

    doomedgame Member

    Joined:
    Jan 26, 2017
    Messages:
    151
    Likes Received:
    9
    New bearing are cleaned and installed one bearing on the clutch is now slip fit for easy disassembly. Forgot my bottle of gasket goo at the shop so will be tomorrow before bottom end is back together.
     
  7. doomedgame

    doomedgame Member

    Joined:
    Jan 26, 2017
    Messages:
    151
    Likes Received:
    9
    Well almost back together ran into a problem the keyway on the crank is a little thinner then the old one so the keys do not fit.

    Talked with my local auto parts store they carry vp-110 fuel
     
    #27 doomedgame, Feb 7, 2018
    Last edited: Feb 8, 2018
  8. doomedgame

    doomedgame Member

    Joined:
    Jan 26, 2017
    Messages:
    151
    Likes Received:
    9
    The woodruff key problem will hold this up there metric and could not find 2mm ones on Ebay in USA so had to order from the UK.
     
  9. crassius

    crassius Well-Known Member

    Joined:
    Sep 30, 2012
    Messages:
    3,843
    Likes Received:
    104
    yes, all factories use either thick or thin for all 4 keys - one kit recently changed the units on the shaft to thick key types while leaving shaft keys thin so all keys are loose fit
     
  10. doomedgame

    doomedgame Member

    Joined:
    Jan 26, 2017
    Messages:
    151
    Likes Received:
    9
    anyway plan to do a test fit on the frame to see how that carb fits today
     
    #30 doomedgame, Feb 9, 2018
    Last edited: Feb 9, 2018
  11. doomedgame

    doomedgame Member

    Joined:
    Jan 26, 2017
    Messages:
    151
    Likes Received:
    9
    Well the carb fits nicely.

    The cut up reed setup

    But this is strange may have a problem ( not a problem)
     
    #31 doomedgame, Feb 9, 2018
    Last edited: Feb 9, 2018
  12. doomedgame

    doomedgame Member

    Joined:
    Jan 26, 2017
    Messages:
    151
    Likes Received:
    9
    With the intake opening up to the top of the piston this setup will only work with reed valves. When it is at that point the reeds will be closed making the intake path a 3rd transfer port because the window in the piston is also in the intake path. Clever but made me say what the
     
  13. doomedgame

    doomedgame Member

    Joined:
    Jan 26, 2017
    Messages:
    151
    Likes Received:
    9
    It's a 44mm stroke I checked
     
  14. cannonball2

    cannonball2 Active Member

    Joined:
    Oct 28, 2010
    Messages:
    3,558
    Likes Received:
    22
    I was going to use a 40mm bottom end. The Stihl saw that the cylinder/piston come from uses a 40mm stroke. That keeps the port timing correct. We may be taking about two different things.
     
  15. doomedgame

    doomedgame Member

    Joined:
    Jan 26, 2017
    Messages:
    151
    Likes Received:
    9
    You asked me if the +4mm stroke was from a 38mm crank or a 40mm crank I was just answering your question
     
  16. cannonball2

    cannonball2 Active Member

    Joined:
    Oct 28, 2010
    Messages:
    3,558
    Likes Received:
    22
  17. doomedgame

    doomedgame Member

    Joined:
    Jan 26, 2017
    Messages:
    151
    Likes Received:
    9
    bore 48mm stroke 44mm = 79.64cc

    Started to fix the head the ridge on the Jake style head is now gone
    The spark plug is two short and its a long throw so got a end mill bit to take material form the top of the spark plug area. Will post pics when i get time.
     
    #37 doomedgame, Feb 12, 2018
    Last edited: Feb 14, 2018
  18. doomedgame

    doomedgame Member

    Joined:
    Jan 26, 2017
    Messages:
    151
    Likes Received:
    9
    Plug is fixed used a router with a end mill bit. Just have to reshape the head a little.
    before
    20180213_072441.jpg
    below is the after not sure why some will give me the option for a image and some will not
     

    Attached Files:

    #38 doomedgame, Feb 13, 2018
    Last edited: Feb 14, 2018
  19. doomedgame

    doomedgame Member

    Joined:
    Jan 26, 2017
    Messages:
    151
    Likes Received:
    9
    Wanted to get more done on it this week but waiting on parts and a semi truck delivery after 12 years finally got a motorcycle.
     
  20. doomedgame

    doomedgame Member

    Joined:
    Jan 26, 2017
    Messages:
    151
    Likes Received:
    9
    Good news the crank keys are here and fit.
    WOODRUFF KEYS: 2mm x 3.7mm

    Edited
    The clutch side is a little to tall for the gear to go on will have to grind the key down a hair
     
    #40 doomedgame, Feb 14, 2018
    Last edited: Feb 21, 2018

Share This Page