BW80 aka “The Witch”

Discussion in 'Some Assembly Required' started by greasyfatman, Dec 3, 2020.

  1. greasyfatman

    greasyfatman Long timer

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    Well Reading all the threads here and looking at the skill talent and determination of builders, I am posting my build.

    My build thread is in hope to get help and motivation from all of you. A5476A2D-DE4C-467D-A7A3-74EFF3218EEF.jpeg

    these two are Hansel and Gretel. Mild porting external fork spring atv shock. And thats Stenchie the dog.

    What I need is a development bike thats where the witch comes in.
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    So far everything is going wrong. Above is the cylinder that has been ported and I measured the piston wrong.

    Crank big end bearing has too much movement. Ordered a replacement crank.
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    key hole is 18 degrees out.

    I sent the OE crank to millennium for rebuild after deciding I didn’t want to buy a press ( feel free to ridicule me into buying tools) I also sent the cylinders for the two other bikes, had them packed at a mail box store. Both cylinders had fins broken in shipping.

    picked up an aluminum wheel kit and its off center by 23mm. Will take the spacer to Mechinest that also rides. Pay him with beef and bacon.

    53EE25CF-5DFA-4170-B6E2-5876C5B6E377.jpeg

    Well shit here we sit.
    Plans include making an intake for a 20mm carb, making a pipe? Maybe adapting a 19mm id exit to the fmf pipe. Custom ignition ? Some head shaping?

    have to develop a good test run that records Acceleration rpm.

    the two bikes have been a blast at events people really get akick out of them.

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    They keep up with big bikes off road?

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    some of my drunken notes. The powder coater blasted all the bearing surfaces and the inside of the forks too.
    #1
  2. greasyfatman

    greasyfatman Long timer

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    I can’t consistently measure anything. My back ground is RF engineering. Looking for reasons to get into CAD and 3D print. Maybe a mini mill. Anything that makes me more marketable I will invest in.
    #2
  3. greasyfatman

    greasyfatman Long timer

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    B132F840-2DAD-4647-BA23-8F6267E5D9FD.jpeg
    worked surface cleaned up. Knocked the cobwebs off my brain and think I have the transmission corrected.

    got the wheel spacer to the Mechinest and two shock spacers being made. Probably have 6 x16 hour work days this week.

    also got the 1000lb/in spring on the fully adjustable shock 9A32DE5B-7DDA-41C6-8406-CAD7FCF98749.jpeg
    #3
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  4. Pezz_gs

    Pezz_gs Cant ride for crap

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    So looking forward to this . . . . :lurk

    I suffer from Big Wheel sickness too . . . . :hmmmmm
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  5. greasyfatman

    greasyfatman Long timer

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    EFFA2536-2E10-414C-8B6B-70A7F38F4802.jpeg F3466E08-7561-434E-9C9F-59F8476F7821.jpeg
    had to file some damaged threads on the crank.
    Had an extra washer in the trans the cases didn’t want to go back together.

    48.5mm piston installed, boring to that size moved the ports a good bit. Think I have it times close to the other two.


    Didn’t have the screw to hold the stator plate. Started looking at programable AC-CDIs.
    #5
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  6. greasyfatman

    greasyfatman Long timer

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    047A6834-2FB2-4650-8B4E-ADBD8BD54EB8.jpeg 91E24267-634D-4506-A85C-4667234C13C5.jpeg


    will this tire be round when mounted?

    should find out in the next couple days
    #6
  7. greasyfatman

    greasyfatman Long timer

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    Ya buddy I dig some of the stuff you have made. RV125 is on my radar as my next bike. Keep thinking of a big buck build AWD fat tire crf450x.
    #7
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  8. Pezz_gs

    Pezz_gs Cant ride for crap

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    Currently shoving a Dr200 into Reg

    Along with a lot of other styling changes
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    #8
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  9. Nathan_66

    Nathan_66 Been here awhile

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    if you're installing it, a clamp really helps keep bead from popping out when starting and keeps bead away from rim when getting last bit on
    https://advrider.com/f/threads/neduros-tire-changing-class.50717/page-34#post-41303656

    mounting compound may help too. It's a PITA getting tires off those rims!

    Looking forward to seeing the build come together!!!
    #9
  10. greasyfatman

    greasyfatman Long timer

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    Thanks man. I think I am going to take them to a shop tomorrow morning.

    don’t think I have the right studs for the front wheel. May go get some hardware tomorrow too.
    #10
  11. greasyfatman

    greasyfatman Long timer

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    078AACF4-9E95-4A00-B887-D04222814E4B.jpeg

    Shock fitted. Have to get head nuts. Need some hard bolts cant find studs that fit the front wheel. May have RAD make studs.
    #11
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  12. greasyfatman

    greasyfatman Long timer

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    Front tire on my mind.
    #12
  13. greasyfatman

    greasyfatman Long timer

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    496192D6-6517-488B-86FE-59B8BCD80C0B.jpeg

    The back tire is bigger than I thought and the front smaller. Going to look for a rounder front, maybe an inch wider.

    don’t know if I should cut up the intake now, or get the bike running and test after each mod.
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  14. greasyfatman

    greasyfatman Long timer

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    85402356-6544-410A-9492-F8A503303AA6.jpeg

    Have some more parts on the way. I might have to make a seat pan that can add rigidity to the frame. This seat has some fitment issues. Aluminum seat pan. Will order a tig welder soon. Got a welding cart for Christmas.
    #14
  15. greasyfatman

    greasyfatman Long timer

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    I have to clean up, but all the parts are here.
    #15
  16. greasyfatman

    greasyfatman Long timer

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    Have something slight wrong with the kicker but should get a chance to try and start it tomorrow.
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  17. greasyfatman

    greasyfatman Long timer

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    Lets talk Butt Dyno. I am going to change things, make mods, one at a time and make test runs. But I don’t want to loose track of ride ability. I think a can record rpm vs time. Possibly 60ft time.

    short of a dyno any ideas on how to test mods to see if I have improved trail ability?
    #17
  18. VX Rider

    VX Rider Long timer

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    sweet jumps, and burn outs!
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  19. Nathan_66

    Nathan_66 Been here awhile

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    The butt dyno does not lie!!!

    What I do is go WFO right from the start, the harder it is to get your feet on the pegs in time and the harder it is to hold on...the better!
    Once the bike starts taking off faster than you can get your feet on the pegs you know you are on the right track!

    Looking good, it's coming together nicely. Are you welding the muffler pipe to fit? I can post pics of the way it's been welded on my bike if that'll help.
    #19
  20. greasyfatman

    greasyfatman Long timer

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    Thanks man good info. Pics of your welded pipe sound good. Did you go with a larger ID pipe?
    #20