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Wanted - Carbs for XJ650RJ

Discussion in 'For Sale, Trade/Swap, Wanted' started by Hoot, Feb 27, 2021.

  1. Hoot

    Hoot Member

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    Need a set of carbs for 1982 XJ650RJC and security chain. Thanks.
     
  2. Toomanybikes

    Toomanybikes Well-Known Member

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    Are your carbs missing or just all nasty?
    I can help you with that
     

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  3. Hoot

    Hoot Member

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    Emulsion tubes are pitted on the outside, need to do closer inspection of tube insides. Bike runs very rich. Float heights are good. New needles and seats (Keyster). Shaft seals looked good. Jetting is all stock and there doesn’t seem to any parts missing. Nothing else seems untowards other than suspect porosity in one of the carb bodies. I’ll try to get a pic of that and post it later today.

    The carbs were pretty bad when I got the bike and it was obvious that had been apart many times (chewed up screw heads, bowls improperly cleaned, jet slot chewed from wrong size screw driver, etc.

    I was hoping to find a decent rack of carbs, maybe get a good set out of the two.
     
  4. Toomanybikes

    Toomanybikes Well-Known Member

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    I can supply a set of good bodies with new throttle shaft seals would be your best bet. Just swap over all the jets and slides and you will be back on the road. Is your Seca a yics or non yics motor? And what are all your jet sizes right now including air jets in top and the intake side of body, and is the intake and exhaust stock?
     
    Last edited: Feb 27, 2021
  5. k-moe

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

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    And are the air jets in the right locations?
    Anyone who relied on the service manual would have put them in the wrong locations, and the bike would run rich.
    [​IMG]
     
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  6. Hoot

    Hoot Member

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    Lmao! No foolin? Service manual is what I used to put the carbs back together so I’ll be having a look at those jets shortly. Is there a link on this forum to other service manual errors? Thanks k-moe!
     
  7. k-moe

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

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  8. Hoot

    Hoot Member

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    Air jets are in correct positions. Bike is a XJ650RJC, 205 pilot air closest to the engine, 50 main air in the middle.
    On another tact, fuse box is original and not in the best of shape and needs updating. Makes me wonder if it’s not poor electrical supply to the ignition masquerading as rich running condition. Bike runs great with fresh plugs and not fully warmed up but after only 4 to 5 minutes starts acting up. Fresh plugs become very badly carbon fouled within about 20 minutes.
     
  9. Toomanybikes

    Toomanybikes Well-Known Member

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    Had a problem with an xj650rjc last year, someone drilled the jets out about 50% bigger and ran like garbage unless full throttle. Stock is 112 main 43 pilot for an rjc.
    My only other suggestion is send them to me and I’ll tune them on my bike (
    carbs are off right now for rebuilding).

    I’ve done a few sets for other members from across the country. They are very happy they spent the money.
     
  10. chacal

    chacal Moderator Moderator Supporting Vendor Premium Member

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    Make sure that the choke plungers are closing fully and that neither the brass valves nor the seat in the carb body (where the brass valve will close against) are damaged.
     
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  11. hogfiddles

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

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    First, I’d replace carb parts with stuff from Len ONLY.

    otherwise, I’ll ask about:

    Are valve clearances in spec?

    is your gas cap venting properly?

    have you tried running on PRI?

    Missing any vacuum caps?
     
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  12. Hoot

    Hoot Member

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    Carbs are back off the bike and will be gone through again. I was not impressed with the Keyster parts so, yea, OEM needles and seats are on the list.
    I have not checked the valve clearances (laziness and time constraints more than anything else) but plan to do on Sunday.
    Vacuum caps, cap venting and run on prime all checked out OK.

    There seemed to be an intermittent nature to the rich running. Rich condition most noticeable when cruising straight but much less when cornering and on/off throttle riding. Makes me think the needle and seat are leaking slightly when bike is running, and least demand riding (steady speed cruise) would mean fuel level rising whereas accelerating and twisty bits equals increase fuel demand. Fuel bowl level is fine when bike is not running but I have never check when running. Definitely worth checking and diagnose suspected poor needle seating.
     
  13. Hoot

    Hoot Member

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    Choke plungers looked good but will be checked again.
     
  14. hogfiddles

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

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    I HIGHLY discourage you from trying to check fuel levels when running!!!!!!!!!
    How loudly can you say “BOOM!!!!!!”?
     
  15. Hoot

    Hoot Member

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    Ha-Ha. Yes. Boom. True enough.
    I did notice one strange thing when I took the carbs off. The inside of the intake manifolds were wet, but I had drained the bowls in the fall when I stored the bike. Fuel bowls have been dry all winter and no fuel was present when carbs were disassembled. I believe it might be oil, but what would oil be doing in there? Breather issue maybe?
     
  16. Hoot

    Hoot Member

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    Unless I’m losing it, my Haynes manual shows the main air and pilot air jets in the correct position. Picture shows large pilot air jet in the forward most hole and the main air jet in the middle. Page 123. Is this not correct? See pics below.
    The manual however does list the copyright year as 1994. Perhaps a later printing?
    0FFC5232-A079-4E24-B56E-962D49DD0F69.jpeg
    22498939-F736-4ABB-9C78-011303CCA9FE.jpeg
     
  17. tj.

    tj. Active Member

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    Yes, you're losing it lol...it's labelled backwards in the Haynes pic.
    Should read
    A: pilot air jet B:main air jet
     
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  18. XJ550H

    XJ550H Well-Known Member Premium Member

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    correct picture wise but labeled incorrectly
     
  19. hogfiddles

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

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    Correct installation is simple——
    Higher number jet toward front wheel
    Lower number jet toward operator
     
  20. Hoot

    Hoot Member

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    Oh yea. Yes, labeled wrong. Now I see the Haynes error. Thanks tj for confirming I’m losing it (I’ve had my suspicions for awhile) and thanks to the others for your replys.
    While I’ve got you guys, have you run into problems annealing and reusing the copper washers under the needle seat and main jet? I noticed the main jet washer gets pulled a bit concave when the main jet is tighten into the emulsion tube. Is this normal?
     

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