THE BIGWHEEL THREAD!!! Yamaha BW350, BW200

Discussion in 'Thumpers' started by Mr. BigWheel, Feb 4, 2011.

  1. dorkpunch

    dorkpunch Oops...

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    Blackfoot, ID
    By immersion, right? :deal


    :lol3
  2. XpressCS

    XpressCS Must. Have. Lumens..

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    The big box California
    Might be a bit late here, but the ATC 250R was air cooled 1981-1984, the 1985-1986 models were pumpers.

    I'm a massive 3 wheeler nut, same with big wheels, this thread has my attention :ear
  3. truckinwagen

    truckinwagen Adventurer

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    yeah, I know about the early 250r being air cooled, but the only one local that was reasonably priced was not one of them.

    hoping it stops raining tomorrow so I can get back to work on it.

    not too much more to do, but without an indoors to work on it, I am at the mercy of the rain gods.

    -Owen
  4. XpressCS

    XpressCS Must. Have. Lumens..

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    Time to get yourself one of them fancy awning things.
  5. truckinwagen

    truckinwagen Adventurer

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    its on the list, but on the student budget it was either the new motor or an awning to install it under, not both :D
  6. truckinwagen

    truckinwagen Adventurer

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    Oddometer:
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    well, the motor is in and bolted down, forks on, wheels on, carb installed(although I need to figure out a filter/airbox)

    I need to finish up a few things(tomorrow) but the bike is almost done!

    left to do are:
    new, longer primary chain.
    install handlebars/new controls(clutch lever, throttle, etc...)
    hook up brakes
    install new trimmed up wiring harness


    then it is time to fire it up and take a test ride!

    it still needs longer shocks for the rear end, as the fork is raked way out, and the ground clearance is low, but that will happen a little later, and wont keep me from riding it a bit.


    I took some pics of the motor mounts and the way the bike sits, but need to upload them.
    when I do(later tonight) I will post the awesomeness!

    -Owen
  7. Mr. BigWheel

    Mr. BigWheel b00b

    Joined:
    Mar 4, 2009
    Oddometer:
    756
    Location:
    South central Alaska
    That's totally awesome. When you're done with your project maybe you could help me put a turbine engine in my lawnmower? If you have a spare afternoon.

    Although, with the weather we've been having, there won't be a need for the mower much longer.

    How are you handling the different size sprockets between the engine and the swing arm sprocket? Are you putting 530 size on the engine or changing the one on the swing arm to a 520?

    Kudos on the progress. Keep it up.

    Regards,

    Mr. BigWheel
  8. truckinwagen

    truckinwagen Adventurer

    Joined:
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    Oddometer:
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    I am going to leave the sprockets alone, the 530 chain will fit on the 520 sprocket that is on the motor(its just a little wider) and will run fine.
    I have run similar chain/sprocket setups before and had no issues with a wider chain than the sprocket was made for.

    thanks for the kudos, I try to do my best, it does not always work out perfect the first time, but where is the fun in having everything work all the time?

    as for the turbine, not sure I can help you there, but if you wanted to turbocharge it, I do have experience installing them on motors never designed for them.

    -Owen
  9. truckinwagen

    truckinwagen Adventurer

    Joined:
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    as promised, here are the pics!

    its not as pretty as it could be, but bear in mind this was all done without a welder, on a porch, with hand tools.

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]



    this is how it sits:

    [​IMG]

    this is how I think it should sit:

    [​IMG]

    and this is how much longer the shocks need to be to accomplish that:

    [​IMG]

    all in all not too bad, in my opinion.

    and it looks like my hopes of getting it done today went out the window with this rain.

    maybe I can find some time next time it is sunny.

    -Owen
  10. dorkpunch

    dorkpunch Oops...

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    Impressive. I have a garage, a welder, and lotsa tools and it still would have taken me months to finish something like that... :lol3

    That said, I think you will probably want to weld the rear engine mount sooner rather than later, and also make some bushings where the swing arm bolt goes through even if it's just a whole ton of washers stacked on the bolt. Can't wait for the ride report!

    Did you ever tear the old engine down to see if the cdi/coil was the cause of it melting?
  11. truckinwagen

    truckinwagen Adventurer

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    no, I have not torn the old engine down yet, it is on the list though.

    as for the spacers, yes that is happening, I just had to get the frame bolted up to measure to make them.

    as for welding the rear mount, I will lay a bead on it as soon as I have access to a working welder, for now it will have to do.

    -Owen
  12. Shercoman

    Shercoman Been here awhile

    Joined:
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    Oddometer:
    457
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    Pine,Colorado
    Truckin,
    I greatly admire your ingenuity and skills so please take the following as constructive "advice."

    As a tool maker,engineer and fabricator with many projects under my belt I'd like to offer some suggestions.

    The BW frame uses the engine as a stressed member. Since there is no lower engine cradle,the engine itself has to provide the strength to hold the frame together and stabilize it.
    Your engine will be strong enough but the mounts you have made will not.

    The front mounts may be good enough but would be considerably stronger if you weld the plates to the frame.
    The back mounts need some more work.
    If you land this from a jump,the frame will try to "open the horseshoe" that is the engine cradle.The front mount will try to pull the back of the engine away from the swing arm pivot.
    The lower mount using the u bolts will do little to prevent this. They will break or deform as the angle iron is already doing from the bolts being tightened.
    The upper mount is two "L" shaped pieces of iron bolted together. If you make spacers to fill the gaps between the brackets and swing arm you will have good side to side strength but virtually no strength when the motor tries to move away from the swing arm bolt.Simply welding the two pieces of angle together will not give you the strength you need. The forces will try to straighten them out. You need the top plate to hold the bracket in the shape it is now.

    Laying a shaped plate on the top and bottom of these two "L" brackets,that covers them from one side of the engine mount to the other side and extends backward out over the swing arm bolt,and then welding all together will greatly strengthen this area.Do top and bottom if you can.

    My concerns are this,if you ride this very hard at all, this frame will be a "flexible flyer" and quickly break.The results could hurt you.

    Please go back and look at the conversion I did with the two stroke.I fabricated new lower frame rails to tie everything together and then used a thick aluminum skid plate on the bottom as a stressed member also.

    Please take this from a fellow BW'er that would rather not see you get hurt and continue to develop your obviously creative fabrication skills.
    I'll be glad to help you in any way I can. If welding is an issue, you can send me anything and I'll weld and send back.
  13. truckinwagen

    truckinwagen Adventurer

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    yep, all those things are on my mind.

    the current mount setup is just a mock up to make sure all the holes are lined up.

    the only reason things were not welded is that the welder I had up here broke, I do have one that I will be bringing up to finish the project with.

    that said, this is going to have to hit the back burner for a while.
    between school and work I dont have much time, and what I do have is spent on homework/housework.

    and on top of that, I have to fix our fence and cut up some trees that the storm broke the other night.

    -Owen
  14. Mr. BigWheel

    Mr. BigWheel b00b

    Joined:
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    Location:
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    We've had biblical-style rain and windstorms that have wreaked havoc across southcentral Alaska. Owen's 200 project may have gotten washed or blown off his deck. Haven't been riding in weeks.

    Saturday was different. Cliffosaurus and I scheduled some perfect weather for a ride up the B-29 Trail.

    Here's Cliff fording a rain swollen stream:

    [​IMG]

    (Note the brake lever being used on the clutch perch and the absence of a brake lever. A small concession to the original design: the levers can be swapped and the ride continued in the event of a tipover)
  15. DEAVER

    DEAVER Been here awhile

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    Location:
    Spaniard's bay,Newfoundland. Canada
    sweet pic
  16. sanjoh

    sanjoh Purveyor of Light

    Joined:
    Feb 13, 2007
    Oddometer:
    5,400
    Location:
    Mountains of Central Florida:)
    Had this 86 BW200 follow me home:D

    [​IMG]

    Purchased from original owner who has had it since age 12.

    Front and rear plastics are kaput. Is DC plastics the only place for replacements?

    PO had drained carb and tank before storage. Cleaned tank, carb and it started on the second kick:clap

    When to start it again and broke the kick start output shaft:cry

    Has anyone put a warrior engine in a BW? 350cc 6 speed:evil
  17. Mr. BigWheel

    Mr. BigWheel b00b

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    South central Alaska
    Nice find sanjoh!

    I haven't heard of too many engine transplants in the 200s. The Warrior engine would make your bike into a slightly higher performance BW350 with an extra gear.

    I'd like to know if the Warrior transmission could be swapped into a BW350 bottom end, as that extra gear would come in handy sometimes.

    The angle between the cylinder and case halves is different between the Warrior and BW engines and that might complicate the installation. However, the mounts seem to be very accommodating for a number of builders.

    As far as I know, DC Plastics and occaissionally ebay, are the only sources of plastics. At least you have you side panels and that puts you miles ahead in the game.

    Here's another shot of Cliffas Pastrana charging hard above the tree line in the Talkeetnas:

    [​IMG]
  18. sanjoh

    sanjoh Purveyor of Light

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    That is an awesome pic, regardless of the bike!

    Kinda had trust that he wouldn't land on you:D

    Thanks for the info.

    Look forward to getting the BW motovating.
  19. Shercoman

    Shercoman Been here awhile

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    Pine,Colorado
    You Alaska guys post the coolest pics!!!! :clap
  20. kozaz

    kozaz n00b

    Joined:
    Apr 14, 2011
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    5
    Silly question?
    Are there any pros/cons to the BW350 vs BW200?
    I keep thinking a BW200 would be easier to throw around but I never been on either. Besides price and availability, is there anything else?