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XJ and quite frankly, cycle noob.....

Discussion in 'XJ Technical Chat' started by Nastn8, Feb 3, 2017.

  1. Nastn8

    Nastn8 Member

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    Getting started..... XJ550RH. Some of you have already purchased parts from me, and all of you have welcomed me. I'm going to be tearing into this thing soon. Here's what I'll be checking:
    Valve clearance, clutch condition, I'll be bagging and tagging the Mikuni BS28's.....

    Here's what I know I'm replacing and/or refurbishing:
    -Front brakes; pads, caliper and master rebuild, braided hose.
    -Jets, 6 sigma. I read the thread. No pods, thank you. But I aquired this bike sans airbox. I have an idea:cool: for my own box using a k&n panel filter, baffles and velocity stacks inside...And Len has me covered once i dig into the carbs....
    -Petcock, and tank, but where do I find the old formula kreem? This new stuff doesnt seem to work. Or do I run it dry
    -While we're on fuel....I havent been able to find out for sure if this bike has hardened valve seats... The shop manual talks about cutters for reseating, as if they mean hand cutters, which indicates to me the seats arent hardened. Lead additive?
    -Oil filter??? I know this may seem stupid, but the crap i deal with using Napa filters (i.e. ford 6.4 diesel fuel filters wont prime) has taught me to never skimp here. Whats good?
    (I read about the Jaso MA oil but I've had a few wet clutch dirtbikes, so i won't screw that up....again)
    -Fork fluid. This things been sitting so I'm throwing all liquids in the waste oil burner at the shop.


    So here a just a few of my questions....
    Can I buy just the valve pads I need? Or do I spring $130 for a kit?
    Clutch discs?
    Is there a block off available for the tach drive? (if not, does someone have a threaded cuff from a wasted cable I could buy to tig shut and install to cover the unit?)

    All ideas, cautions and advice will be appreciated! In the meantime, i'll keep reading.

    Thanks-Nate
     
  2. Nastn8

    Nastn8 Member

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    Oh yeah, And rear brake shoes....Thanks Fitz
     
  3. Polock

    Polock Well-Known Member

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    do yourself a favor and put out a APB for a airbox. unless it's just something you want to do, then go for it.
    dry if it don't leak, but Caswell has stuff that works, try not to use Kreem.
    no, regular pump gas, no lead additive necessary.
    stock ones work just fine, see chacal about a spin-on adaptor
    Hogfiddles has a shim pool
    see chacal
    i don't think so but there should be.
     
  4. dkavanagh

    dkavanagh Well-Known Member Premium Member

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    I saw (I think Len) had the tach block-off. I re-built mine, but I know you're going a different direction, so check with him.
     
  5. Nastn8

    Nastn8 Member

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    Thanks Polock, Dave. I love fabricating, this airbox thing looks like a challenge and thats attractive. However, the right way to do it is to have a baseline. I would need dyno results of a stock unit to compare to. And I would be looking at strictly power gains, losses.... I'm mostly interested in flat spots. Because if the torque and hp curves are smooth, and slightly resemble that of a stock bike, they can be raised and lowered with fuel and timing. Plus if I dyno the bike I'll be able to see afr's. I saw the ingenious little plugs in each header primary.... :D:Blackalien
     
  6. Nastn8

    Nastn8 Member

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    (WOULD NOT be strictly looking at power...)
     
  7. rocs82650

    rocs82650 Well-Known Member

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    +1.

    Gary H.
     
  8. k-moe

    k-moe Pie, Bacon, Bourbon. Moderator Premium Member

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    Chacal does carry the tach-drive block-off, and has thm in stock.

    The math to determine airbox volume isn't too difficult, and since you're not after making it anymore of a hot-rod than it already is you won't need to get into the math required for figuring the airflow characteristics to improve cylinder filling. For a baseline you can build a mock-up facory airbox out of card and play with that volume for packaging purposes if you can't find a factory airbox.
     
    rocs82650 and Nastn8 like this.
  9. Nastn8

    Nastn8 Member

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    I mean, my idea uses basically the same cavity in the frame. It's not a "ram air". Just a box with baffles and long velocity stacks inboard. I'll use a panel filter where the air comes in and it will be sealed. E46 BMW M3 has this same concept in use on their plenum design, also, this way I can position the crank vent to utilize the stock hose. I believe volume is as easy as HxWxL=V I'll most like use metric to calculate cc's. From what I've read, the stock airbox makes the carbs tricky to get off. That may explain the few fragments of black plastic that were in the bottom of the Tupperware tote I received the carbs in.... I fear that is what remains of the stock box. My idea will be assembled in sections so as to facilitate an easy removal. I invision polycarbonate sides to this airbox, allowing one to view the velocity stacks and chambers from the sides. I plan to run an antigravity 8 cell, laying flat, tucked under the seat pan, behind the airbox.... Off to work now to sort through the box of aluminum 2" mandrels. They will fit tight over the outside of the coupler boots, just as factory, bend down to clear the frame. All of equal length... Soon I'll draw my idea to share. A little paint by number lol.
     
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  10. Nastn8

    Nastn8 Member

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    Anyone else on the hardened (or not) valve seats? I'm quite paranoid about running pump gas without lead additive, sans knowing they are hardened. Can you hear me chomping my nails? Also, whats the best miracle juice for preventing those pesky enzyme deposits thanks to the ethanol....... And I wonder.... Have any of the policy makers that required the ethanol done an analysis on the carbon footprint of all the carbs and related parts the average consumer is throwing out prematurely? Perhaps a topic for another thread... I've been using startron with my lawn equipment, but that's lawn equipment. None of my Briggs and Strattons redline at 10k....
     
  11. Stumplifter

    Stumplifter Well-Known Member

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    Do not worry about a lead additive. I know of no one on this site that uses it. I used to use it in a 75 IH Scout II but that is a topic for a different forum . . . . .

    Ethanol, is an unfortunate reality. My experience/ understanding is that as long as you aren't letting it sit for extended periods of time it should not be a problem. Ride the bike often, take good long rides (tell you significant other that you HAVE to go for a 3 hour jaunt because it is a maintenance procedure . . .) then when winter comes, add some Stabil to the tank, or top off the tank with non-ethanol premium and call it good. Some folk drain their carbs in the winter.
     
  12. k-moe

    k-moe Pie, Bacon, Bourbon. Moderator Premium Member

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    The bikes were built to run on unleaded. Says so in the owner's manual.

    Some folks don't worry about using ethanol blended fuel either (E-10), because that was around when the bikes were designed, and Yamaha took that into account (use Stabil's ethanol product for winter storage though).
     
    Last edited: Feb 5, 2017
  13. Nastn8

    Nastn8 Member

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    Off topic.... Hey Len, I got my money on the Falcons! It's time for a shutout against new England!
     
  14. hogfiddles

    hogfiddles XJ-Wizard, Host-Central NY Carb Clinic Moderator Premium Member

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    Nast.... let me know what sizes you need

    Dave
     
  15. Nastn8

    Nastn8 Member

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    lol. You Mean Champion T's? That Say Patriots?:oops:
     
  16. Nastn8

    Nastn8 Member

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    Seriously though....If your referring to valve shims, Awesome! I suppose your pool is a trade? Plus Donations?
     
  17. XJ550H

    XJ550H Well-Known Member Premium Member

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    so close yet so far
     
  18. Nastn8

    Nastn8 Member

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    That was an exciting game though. So back on topic. I'm thinking airbox removal is suicide because the fine engineers at Yamaha had carefully constructed a resonant box. My guess is that with these puppies revving to 10k, theres a bit of valve overlap. They probably made the midrange crisp by taking advantage of resonant frequency. Do these airboxes have an inlet tube? Perhaps with a bell mouth? I only have external pictures so far to referrence. Btw.... velocity stacks on the way. So...... would I be the 500th moron to attempt this?o_O
     
  19. Nastn8

    Nastn8 Member

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    Also , looking at the diagrams, I am thoroughly impressed with how the bs28's operate. And I can clearly see the air jet being as important as fuel. Theres a symbiotic relationship between them all. Careful timing of diaphragm actuation, fuel atomization. I'm quite excited to even get this a little wrong. Well above my paygrade. But I've found some incredibly interesting articles written by engineers giving up some formulas. I need math tutoring..... K-Moe? You were saying something about volume?
     
  20. Nastn8

    Nastn8 Member

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    Oh and thanks for the manuals Paul!
     

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