XR650R fires when cold

Discussion in 'Thumpers' started by baachor, Jul 11, 2013.

  1. baachor

    baachor Adventurer

    Joined:
    Jun 24, 2013
    Oddometer:
    65
    Location:
    Costa Mesa,CA
    Hi,

    I bought this bike recently and it starts having issues when starting. It fires in low RPM and engine even shots off when I rev it bit while warming up. It actually died on me on STOP sign today.

    What could be the problem?Things I changed:

    - I'm using 91 gas. (not sure what original owner used)
    - There used to be this terrible "peace of nothing" instead of original backfire screen in air box,and original foam.
    (so I put in backfire screen from XR's only and UNI) I have tried to put in back original peace of s*** with stock foam and still fires.
    - Changed spark plug but it did it before anyway

    Also I found there is this inline fuel filter instead of one in tank.

    Or could it be higher humidity we have here in California now?

    Or do I need to adjust needles? (haven't wholly cleaned carb yet,just cleaned it bit on bottom-no dirt)

    Rest of RPMs are fine when I ride,it's mainly low RPM.

    Stock carb
    T4 pipe
    Half choke

    It doesn't start easy (even previous owner had trouble),maybe it's just me :lol3
    #1
  2. cognugget

    cognugget n00b

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    what jets. Mine takes 1 kick full choke then 1 kick half choke to fire when cold.
    #2
  3. sintax

    sintax Been here awhile

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    After having my XR for a few years I'll start this one off...

    Any new XR should have the following done.

    1) check and adjust valves
    2) detail strip and clean the carb thoroughly. Ensure all jets are clean, ALL passages clear. Measure float level, adjust if necessary. Record all jet and needle settings.

    Once the above had been done report back and we can talk. It's a big crap shoot until the above is done.

    Best of luck
    #3
  4. sintax

    sintax Been here awhile

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    Oh and also confirm if you are running the restricted carb manifold...
    #4
  5. baachor

    baachor Adventurer

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    Hi Sintax,

    I'm going to clean all right now. I did valves yesterday again and seems like one of exhaust valves were too tight with no free play.FIxed that.Going to check it again just in case.And will post all details you wanted.

    I don't know what that means.Sorry I'm new at R.

    #5
  6. sintax

    sintax Been here awhile

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    Good man! make sure its spotless.

    For the XR there were 2 intake manifolds produced. One that was used on smog equipment bikes are "restricted" they have a smaller intake size where as the HRC part, is opened up and has much better flow. This is a normal upgrade done during the "uncorking" procedure.


    Here is a pic of the restricted...

    [​IMG]


    And here is the unrestricted....

    [​IMG]


    BTW, where in SoCal are you? I'm in Riverside.
    #6
  7. kubiak

    kubiak Long timer

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    If you still have the problem check your stator or excited coil thingy. My xr600 did the same thing and I put a new stator Assy in and back to one kick starting hot or cold.
    #7
  8. baachor

    baachor Adventurer

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    Hi sintax,

    it took me extra time as I couldn't unscrew the link arm screw,had to use Dremel (gotta need new screw in there)
    So here we go:
    1. manifold is unrestricted
    2. jets are: pilot 68S, main 170,throttle needle in middle (3th) position,pilot screw in 7 full turns
    3. spottles :D

    I live in Costa Mesa. You are close :D

    Thank You for helping,I appreciate it! :clap

    kubiak,
    I'm actually in process of getting rewound one from BD as it is stock stator :huh
    So that would fix that if it is the issue.

    Thanx :D

    #8
  9. kubiak

    kubiak Long timer

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    thats good about the stator. let us know how its going.
    #9
  10. baachor

    baachor Adventurer

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    Yea, it needs it. Lot of work,all is stock except tail and LED blinkers (which won't flash even with LED flasher=one of many reasons it needs new stator)
    Did you rewind yours?

    Btw,I found this piece felt from carb while I was getting needle jet off. It is rusty and tiny. What the heck? Where it came from? It is rusty so assuming it's not from inside,but it felt when I was poking needle jet off with long stick from top. wierd

    I noticed #17 between needle jet #3 and needle jet holder #21 is missing on schema. Is this it?


    [​IMG]

    #10
  11. kubiak

    kubiak Long timer

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    i got a 200 watt ricky stator for my old xr. the symtoms i was having was it would start in the morning no problem but after i stopped when it was hot it wouldnt restart till i let it cool down about an hour or so. it also had a low speed misfire. after the new stator everything was great.
    #11
  12. baachor

    baachor Adventurer

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    That's strange that stator would do that.

    I was about to send my for rewinding today,but waiting what sintax thinks is my problem.Then I will put it all together and try it out tomorrow after work.
    And send stator out on Monday. Then electric journey starts :rofl

    #12
  13. Trl Rdr

    Trl Rdr Big Red Bird

    Joined:
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    Location:
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    Question? I got a new stator, no rewind.
    If you send one in for a rewind do they check the windings for the ignition? Or do you get the same one back with new lighting coils and your old Ignition coils?

    Sent from my DROID RAZR HD using Tapatalk 2
    #13
  14. baachor

    baachor Adventurer

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    I'm not sure. Good question. Might call them up and find out. They are closed for weekend. BajaDesigns

    #14
  15. kubiak

    kubiak Long timer

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    Im not sure on that one but i bought the new stator from ricky stator and it came ready to bolt on with new windings and two new exciter coils. the exciter coil is what went bad on my xr. my stock xr stator had one exciter coil and i got the new one in the mail and it had two on it. i called them and they said bolt it on its the updated one. so i did and it was perfect.
    #15
  16. kubiak

    kubiak Long timer

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    my xr i did this on was a 89 xr600.
    #16
  17. sintax

    sintax Been here awhile

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    Ya, gotta remember things expand and contract due to temp. This is really not that unusual for these types of components. Generally hard to troubleshoot for sure.
    #17
  18. baachor

    baachor Adventurer

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    what it means "fuel screw out 1 1/2 to 1 3/4"?

    also I remember I accidentally moved nut on needle jet holder while cleaning it first time few days ago,which could mess it up??? (reading it at the end of that link thread)

    enough for today

    any idea on what is that rusty tiny piece I found?
    #18
  19. sintax

    sintax Been here awhile

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    Well, good news it it looks like the carb is jetted correctly, or at least close enough to start with.

    That part you piece you pulled out of the carb... i dont know where that could have come from. I'd say its good you have it out, foam like that would only continue to break down with contact to gas.

    I'd toss that carb back on there and see what you get now. Report back what you find

    Baja Designs rewound my stator. They do a great job and have some serious output. I'm not sure what BD does, but its a different wind then anyone else. They are the only one that requires modifying the stator housing due to the size of the windings.

    BD should be able to verify functionality of your stator as well.
    #19
  20. sintax

    sintax Been here awhile

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    another random thought i just had...

    The carb has an idle screw that raises and lowers the idle. You want to have the bike idle around 1400 rpm. With too low of a idle setting, it can effect the starting, as well as give you issues with the dying at stop signs and dying after wacking the throttle
    #20