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Bushyboy's build thread

Discussion in 'The Garage' started by Bushyeyed1, Nov 25, 2018.

  1. Jim

    Jim The thrill of victory and da agony of da feet. Top Contributor XS650.com Supporter

    You replaced the stator... which means also the crank sensor. I'd definitely recommend checking the timing. These bikes have a history of holing pistons if the timing is advanced. A little work now could save a lot of work and money later.
     
  2. 5twins

    5twins XS650 Guru Top Contributor

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    Yes, the ignition pick-up was mounted and timed to and on the original stator. With this new stator, it could be off a little. And even if it's not, I think these bikes run better (and stronger at higher speeds/RPMs) with the timing retarded a hair. Not much mind you, just a couple degrees.
     
    TwoManyXS1Bs, Superjet and Bushyeyed1 like this.
  3. Bushyeyed1

    Bushyeyed1 XS650 Addict XS650.com Supporter

    My wife made me some decals for my bike. Posted an ad in the classified section if anyone is interested in a set.
     

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    Jim, Mailman and TwoManyXS1Bs like this.
  4. Bushyeyed1

    Bushyeyed1 XS650 Addict XS650.com Supporter

    Well made it to the gas station today. And rode around a little. Didn't cut off on me this time. Need to make a few more adjustments and dail in the carbs. Right now I'm running two sizes up on main jet or a 137.5 and the stock pilot on bs34 two and 3/4 turns out. I have read tech articles and do have experience with jetting dirt bikes at least. Anyone got a similar setup at around sea level; only upgrade is the ya mama pipes stock carbs and airbox?
     

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    Jim likes this.
  5. 5twins

    5twins XS650 Guru Top Contributor

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    Your BS34 carbs were highly E.P.A. mandated and basically "strangled", so it's not going to be exactly like jetting a dirt bike. Pretty much any change to intake and/or exhaust with these BS34s will require some jetting changes too. These usually like 3 to 3.5 turns out on the mix screws. Idle circuit usually needs tweaking too, either a size up on the pilot or a couple sizes down on the air jet.
     
    Last edited: Feb 19, 2019
    Bushyeyed1 likes this.
  6. Bushyeyed1

    Bushyeyed1 XS650 Addict XS650.com Supporter

    Thanks for the advice 5twins. I guess I mixed up the location of air mixing screw being on the front of the throttle not the back. I will turn that sucker the other way and richen her up at idle.
     
  7. 5twins

    5twins XS650 Guru Top Contributor

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    Yes, you're not dealing with an air regulating mix screw on these carbs but rather a true mixture screw that regulates fuel (more correctly, the already made fuel/air mixture coming from the pilot jet). Turning it out makes the idle circuit richer.
     
    mrtwowheel and Bushyeyed1 like this.
  8. Bushyeyed1

    Bushyeyed1 XS650 Addict XS650.com Supporter

    So the Army is moving me to Hawaii this Summer and it seems my bike will have to pass a little more stringent inspections then here in North Carolina. Glad I still have my reflectors and stock exhaust, but now that means I need to change a few things before I move. May be modifying my stock pipes with some new mufflers in the next couple months. Someone may be able to buy my pandemonium's before I move out there.
     
    Last edited: Feb 20, 2019
    Mailman and Jim like this.
  9. Jim

    Jim The thrill of victory and da agony of da feet. Top Contributor XS650.com Supporter

    Ahhhhh..... the life of a G.I. :rolleyes:
     
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  10. Bushyeyed1

    Bushyeyed1 XS650 Addict XS650.com Supporter

    @Jim g.i. grits and g.i. gravy gee I wish I'd joined the navy....

    So I got in contact with the cafe racer club of Hawaii and he confirmed my suspicions. So need to put on reflectors, dot approved turn signals, and as much as it hurts me to say exhaust with mufflers. Probably a good thing but I really like the way she looks. Anyhow might go ahead and post the drag pipes in my parts thread if anyone is interested. That way I don't start tuning my carbs for them and then have to turn around and change it again for mufflers
     
    TwoManyXS1Bs likes this.
  11. Bushyeyed1

    Bushyeyed1 XS650 Addict XS650.com Supporter

    Anyone ever use a needle jet kit to replace the stock needle on the bs34s? I definitely am a little hesitant to drill out the slide though.
     

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  12. 5twins

    5twins XS650 Guru Top Contributor

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    That's the same kit MikesXS sells. I think it used to sold as the Heiden Dyno Tune kit because it was supposedly developed by Heiden in Europe. That seemed to present some problems when trying to use it in this country. Many reported it didn't work very well. Compare the length of those new needles to your originals. I think they were quite a bit longer which would make them leaner, and that means they may only work with quite larger mains (in the mid 140s). But, I don't know, maybe the kit needles are different now. Do compare the lengths though. A replacement needle usually needs to be pretty close to the same length as the original to work.
     
    Bushyeyed1 likes this.
  13. Jim

    Jim The thrill of victory and da agony of da feet. Top Contributor XS650.com Supporter

    I'd most definitely suggest you find a drill press. :yikes: A lathe would be even better. Chuck the slide up in a lathe it'll be perfectly centered.
     
    Bushyeyed1 likes this.
  14. Bushyeyed1

    Bushyeyed1 XS650 Addict XS650.com Supporter

    It does seem the suggested setting for my setup would be leaner on slide needle. It says in the directions for stage one or stock airbox w/ open exhaust is 45 pilot jet, 135 main jet, 3rd clip with 3 mm drilled hole, and 2 /12 turns on air mixture screw. It does state this is for bs34 CV carbs.
     

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    Last edited: Feb 25, 2019
  15. 5twins

    5twins XS650 Guru Top Contributor

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    On a normal adjustable Mikuni needle, changing the clip position alters the needle height by 1mm, and that can make for big changes in how the bike runs. Your new needle looks 2 or 3mm longer so that would be like leaning the needle 2 or 3 steps. That's a lot. These BS34 carbs come from the factory set up very lean to begin with, almost too lean. I don't understand how making them even leaner would help things. But, I guess all you can do is try those new needles and see how they work. But don't be surprised if they don't work well. The usual needle change on these is to the Canadian version of the needle that's in there. It's pretty much the same as the original (length, taper) but has the 5 clip adjustment slots. Also, it's supposed to be installed with it's matching Canadian needle jet.

    Drilling the slide is supposed to make it lift faster. I can't say, I've never tried it. But I don't find the stock carbs to be sluggish in their response to begin with. It's a mod that may give some benefits but not one you can easily "undo" if it isn't any good.
     
  16. Bushyeyed1

    Bushyeyed1 XS650 Addict XS650.com Supporter

    I think I am going to stay with stock needle if it needs it later then may shim or get the canadian needle. I think I will run the 45 pilot jet, 137.5 main jet, and will adjust the air mixture screw as needed. I don't think I'll be drilling out the slide hole.
     
    Last edited: Feb 25, 2019
  17. Bushyeyed1

    Bushyeyed1 XS650 Addict XS650.com Supporter

    Little break for arts and crafts. Just the start of the project for an original yamaha emblem.
     

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    Jim likes this.
  18. Bushyeyed1

    Bushyeyed1 XS650 Addict XS650.com Supporter

    Finally the bike is running like it should. I got the carb all rebuilt. I added new o-rings, adjusted floats, main jet 137.5, pilot jet 45 and air mixture screw is at 2 1/2 turns but I'm gonna richen that up a little. Took her for a spin down the road and I am happy with the performance. Also it was nicer make it over 5 miles without breaking down or oil leaking everywhere.
     
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  19. 5twins

    5twins XS650 Guru Top Contributor

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    Yes, the stock needle is set up rather lean and not adjustable, but when you add larger mains and pilots, they bleed over into the midrange and pretty much correct that lean needle for you.

    [​IMG]

    Yes, these BS34s usually like the mix screws set in the 3 to 3.5 turns out range, even with a larger pilot.
     
    Bushyeyed1 likes this.
  20. Bushyeyed1

    Bushyeyed1 XS650 Addict XS650.com Supporter

    Yamaha logo looks pretty good. I am going to attempt to epoxy the other emblem to see if it turns out looking oem.
     

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