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1981 Yamaha XS650S - Project Bike #5

Discussion in 'The Garage' started by rbirkey, Aug 3, 2019.

  1. Mailman

    Mailman Hardly a Guru Top Contributor

    The bike is looking great. I think you’re gonna like those Avons. By the way I’ve been meaning to tell you how much I appreciate the quality of your photographs, they always look like they could be printed in a magazine.
    Keep up the nice work and your great posts! :thumbsup:
     
  2. rbirkey

    rbirkey TriumphBonneville.org XS650.com Supporter

    Thank you Mailman!

    I've been considering the suggestion by fredintoon to add the second left front brake caliper and rotor to this bike. I have found most of the parts used on eBay and will supplement the additional parts from BikeBandit and xs360direct.com

    Also, interestingly enough, I discovered that an unused Triumph Bonneville seat that I have can be fairly easily modified to fit this bike! I will recover it with a non-branded seat cover and probably go with integrated LED taillight/signals as I did on one of my Bonneville projects.

    xs650-bonneville-seat.jpg

    integrated-led.jpg
     
  3. Jim

    Jim People will come Ray, people will definately come. Top Contributor XS650.com Supporter

    Contact forum member @DogBunny
    He has a some LH brake parts for sale.
     
    Paul Sutton, MaxPete, Mailman and 2 others like this.
  4. rbirkey

    rbirkey TriumphBonneville.org XS650.com Supporter

    Made some more progress today... the Ikon shocks arrived and they add a full 1" to the rear height, plus they look great! Also, my left front caliper arrived.

    new-ikon-shocks.jpg

    left-caliper.jpg
     
  5. rbirkey

    rbirkey TriumphBonneville.org XS650.com Supporter

    Where do people recommend getting new braided stainless steel brake lines for the dual front disc brake setup?

    front-left-disc-caliper-mounted.jpg
     
    Last edited: Aug 16, 2019
    MaxPete likes this.
  6. rbirkey

    rbirkey TriumphBonneville.org XS650.com Supporter

    5twins... I am unsure what needle would be best to start with on this project. I purchased the Cruisin kit which came with the Y265 and Y267. My carbs had the 5HX12's with the single slot. It looks like the #3 slot on these new needles will be about the same position.

    5HX12-stock-needles.jpg

    I will be running UNI pods and the MAC Performance TT Pipes with Reverse cone mufflers.

    MAC-TT-Y650.jpg

    Thanks
     
    MaxPete likes this.
  7. 5twins

    5twins XS650 Guru Top Contributor

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    Personally, I wouldn't use either of the new adjustable needles to start, I'd try the stocker first. You may find it works just fine. Normally, adjustable needles help when you're increasing main jet sizes and those larger mains bleed over into the upper midrange making it too rich (stumbles appear under heavy throttle applications). With an adjustable needle, you can lean it's setting when that happens and "tune" those stumbles out. But, your stock needle is very lean to begin with. The bleed-over from larger mains and pilots usually doesn't cause stumbling, it just makes the midrange right.

    But, let's take a look at those kit needles compared to some original stock ones. The Y265 appears to be a copy of a 5Z1 XS400 needle as far as taper goes, but it is a little longer. It's center slot position matches the single slot in your stock needle. The Y267 appears to be a copy of the 5O2 needle used in the '78-'79 BS38 carbs. It is a little shorter so would be richer when set in the middle slot compared to the stock one.

    [​IMG]

    I have tried the 5Z1 XS400 needle in '78-79 BS38s and like it. It gives snappier off the line performance. This is probably due to it's sharper point. Sustained slide lift doesn't happen until higher up in the RPMs on these CV carbs, like at 4K and above. But, the slides do jump open momentarily when you whack the throttle open, like when you're taking off in 1st. I think the sharper point on this 5Z1 needle gives a richer shot of fuel when this happens compared to the stock 5O2 needle. So, if your midrange doesn't work out with the stock needle, I think I'd be inclined to try the Y265 (5Z1 copy) first. With larger mains and pilots, I'd start with it in the middle slot then tinker with it's setting from there if need be.
     
    Paul Sutton and MaxPete like this.
  8. rbirkey

    rbirkey TriumphBonneville.org XS650.com Supporter

    5twins - I ruined the OEM needles getting them out, so I have to replace them. I bought the Cruiser kit based on your recommendation/experience and was just wondering which of those needles you would recommend for my application... given that I am opening up the intake and exhaust and planning to start with a #45 pilot and #137.5 main... also per your earlier recommendation. So, looks like I will start with the Y265 with the e-clip in the center (3) position to start... and go from there - thanks!

    Also, the new Main Nozzle has a slot in it... what direction does that slot go? I have not been able to find a clear answer or diagram on that. And there are a couple of other parts in this kit that I don't recognize.

    main-needle-nozzle.jpg
     
  9. 5twins

    5twins XS650 Guru Top Contributor

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    If you look in the hole that the needle jet came out of, you'll see a little pin sticking out the side. The slot on the jet aligns with that. There is a hole on the side of the needle jet that feeds fuel to the pilot jet. The pin aligns the jet so it can do that .....

    [​IMG]

    [​IMG]

    That washer is probably for under the main jet.

    The screw is a replacement idle speed adjustment screw with a little different looking head than the original.
     
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  10. 5twins

    5twins XS650 Guru Top Contributor

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    Make sure that hole in the side of the new needle jet that is going to feed the pilot jet is in the right spot. There have been reports of some aftermarket needle jets made wrong, with that hole in the wrong spot. You won't get any gas flowing into the pilot jet if it's wrong.
     
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  11. rbirkey

    rbirkey TriumphBonneville.org XS650.com Supporter

    Yes, I figured out the orientation and you are right about the washers! I will refrain from swapping the idle adjust screws as mine look good. I've discovered that my float pins are bent and bind in the shaft, so I am just going to replace the floats and pins for safety. Also, the float heights were way off ... close to 25mm instead of 22mm. But, everything else is back together and ready to put on the bike! Thanks.
     
    MaxPete likes this.
  12. 5twins

    5twins XS650 Guru Top Contributor

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    The BS34 float pins are splined at the end with the head on it. They get tight going in once they're nearly in all the way. Don't mistake that for them being bent.
     
    rbirkey, MaxPete and gggGary like this.
  13. rbirkey

    rbirkey TriumphBonneville.org XS650.com Supporter

    I see that finding new floats is not easy. The problem I have is that on one of the copper sleeves inside where the pin goes through the float bracket, has broken in half and one side is missing. All I really need is that small copper/brass sleeve. I may have to try to make one from some scrap metal.
     
    Paul Sutton likes this.
  14. 5twins

    5twins XS650 Guru Top Contributor

    17,776
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  15. MaxPete

    MaxPete Life with Lucille...I suggest, she decides. Top Contributor XS650.com Supporter

    Indeed. Mikuni carbs were used by several OEMs and so searching across the brands makes sense.
     
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  16. rbirkey

    rbirkey TriumphBonneville.org XS650.com Supporter

    Thanks. Does anybody know what these 2 rubber parts are?... I seem to remember them being somewhere in the float bowls.

    rubber-parts-carbs.jpg
     
  17. Jim

    Jim People will come Ray, people will definately come. Top Contributor XS650.com Supporter

    Plugs for the pilot jets.
     
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  18. 5twins

    5twins XS650 Guru Top Contributor

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    Yes, you need those in there. They isolate the pilot jets from the fuel sitting in the float bowl so they only draw fuel from the main jet area. The bike will run rich without them. That one on the right looks pretty rough and may need to be replaced.
     
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  19. fredintoon

    fredintoon Fred Hill, S'toon. Top Contributor

    I'd get 4 of them. 2 that replace the originals and t'other 2 for plugging the access holes to the slow-running needles.
     
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  20. rbirkey

    rbirkey TriumphBonneville.org XS650.com Supporter

    I used Eastwood Rubberized Rust Encapsulator to coat the inside of the fenders and chain guard today.

    xs650s-rust-encapsulator.jpg
     
    gggGary, MaxPete, Paul Sutton and 2 others like this.

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