1. Hello Guest. You have limited privileges and you can't "SEARCH" the forums. Please "Log In" or "Sign Up" for additional functionality. Click HERE to proceed.

XJ550 crank no start

Discussion in 'XJ Technical Chat' started by Trvpstar, Sep 19, 2019.

  1. Trvpstar

    Trvpstar Member

    Messages:
    31
    Likes Received:
    2
    Trophy Points:
    8
    Location:
    Nj
    Had this bike for a month ish ride it around no problem but sent it in to a shop to get some carb work done and all of a sudden.. I get a call saying I’ve popped a fuse. I started riding it and just the next day later mid ride bike was sputtering kinda out of 1st and then just died and didn’t want to start. Bike will crank great but just won’t start.. I’m skeptical the shop touched something they shouldn’t have but where should I start? The bike was running like a dream just the day of receiving from the shop.. all my fuses are good even swapped the old ones with new ones and still nothing
     
  2. cds1984

    cds1984 Active Member

    Messages:
    902
    Likes Received:
    195
    Trophy Points:
    43
    Location:
    Perth, Western Australia
    1. Pull a plug and crank - to see if it sparks.
    2. Check the plug to see if its wet if it doesn't
    3. Check the vacuum hose to the tap, if good set the tap to prime (if the plug isn't wet)
    4. loosen the drain screw on the carb bowls to see if they have fuel.

    Fuel and Spark is what makes it go.

    ... a bit of air is handy too.
     
  3. Trvpstar

    Trvpstar Member

    Messages:
    31
    Likes Received:
    2
    Trophy Points:
    8
    Location:
    Nj
    I’m dumb and ran out of gas, false call
     
    raskal likes this.
  4. raskal

    raskal Active Member

    Messages:
    165
    Likes Received:
    72
    Trophy Points:
    28
    Location:
    Abbotsford B.C. Canada
    Thanks for my laugh of the day. I needed it :)


    I'll add that props to you for stating why. We've all done it (well not me,... I'm perfect)
     
  5. Trvpstar

    Trvpstar Member

    Messages:
    31
    Likes Received:
    2
    Trophy Points:
    8
    Location:
    Nj
    Actually just when I spoke too soon, I thought it was for empty gas.. kinda was but not really went for a ride and the bike is slightly sputtering at low rpm unless I floor it it just wants to die
     
  6. raskal

    raskal Active Member

    Messages:
    165
    Likes Received:
    72
    Trophy Points:
    28
    Location:
    Abbotsford B.C. Canada
    after filling the gas tank, did you run it on prime for a minute? Also, did you switch to "Res" ?

    this all might clear up on it's own.
     
  7. XJ550H

    XJ550H Well-Known Member Premium Member

    Messages:
    13,199
    Likes Received:
    3,854
    Trophy Points:
    113
    Location:
    Great North Woods
    happens more than you think.

    bike wont start check fuel, check battery , check ignition.
     
  8. Trvpstar

    Trvpstar Member

    Messages:
    31
    Likes Received:
    2
    Trophy Points:
    8
    Location:
    Nj
    I started it let it run for a bit on choke (it’s kinda cold here) and then went for a ride around my neighbor hood whilst noticing it wanted to die when I downshifted unless I revved it. Then got home and it died
     
  9. cds1984

    cds1984 Active Member

    Messages:
    902
    Likes Received:
    195
    Trophy Points:
    43
    Location:
    Perth, Western Australia
    Another thing to look out for, at least on my bike, if I run it on choke (fuel enrichment) for too long it will foul the plugs pretty fast and needs a good ride to clear them up again.

    Same thing applies though...
    Spark, fuel, air.

    Sounds like the spark is good so,

    1. if you overfill and your tank cap isn't venting properly you can end up with a fuel lock as it wont pull air in from outside and let fuel out. Bit like filling a straw with water, putting your thumb over one end and the water is stuck inside when you try to empty it.
    2. if your air filter is clogged or something is blocking your airbox intake, your plugs will foul and the bike will die at low RPM.
     
  10. Xjrider92117

    Xjrider92117 Active Member

    Messages:
    994
    Likes Received:
    136
    Trophy Points:
    43
    Location:
    San Jose Ca
    Do you have a fuel filter? If so, is it installed correctly?
     
  11. Trvpstar

    Trvpstar Member

    Messages:
    31
    Likes Received:
    2
    Trophy Points:
    8
    Location:
    Nj
    I’ll change the plugs in the am but now all of a sudden my headlight won’t turn on when I turn the bike on... this is getting good ..
     
  12. Trvpstar

    Trvpstar Member

    Messages:
    31
    Likes Received:
    2
    Trophy Points:
    8
    Location:
    Nj
    Well found this connector to be melted inside and noticed the bike kind of wants to start when it’s plugged it but just cranks when I unplug it. What is this connector for?
     

    Attached Files:

  13. cds1984

    cds1984 Active Member

    Messages:
    902
    Likes Received:
    195
    Trophy Points:
    43
    Location:
    Perth, Western Australia
    Pretty sure the 550 has some real differences, electrically, to my gear.
    But that could be the diode package which is part of the electrical mayhem in the headlight bucket.

    Good time to track down an electrical schematic and get the multimeter out.
     
    k-moe likes this.
  14. k-moe

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

    Messages:
    19,613
    Likes Received:
    6,703
    Trophy Points:
    113
    Location:
    The City of Seven Hills
    That is the diode block. You're going to need a replacement, and need to find out why it melted.
     
    Rooster53 likes this.
  15. Trvpstar

    Trvpstar Member

    Messages:
    31
    Likes Received:
    2
    Trophy Points:
    8
    Location:
    Nj
    My headlight bracket came loose and there was a nut in there I’m assuming that’s why, can someone pop me a link to a new one ?
     
  16. XJ550H

    XJ550H Well-Known Member Premium Member

    Messages:
    13,199
    Likes Received:
    3,854
    Trophy Points:
    113
    Location:
    Great North Woods
  17. Trvpstar

    Trvpstar Member

    Messages:
    31
    Likes Received:
    2
    Trophy Points:
    8
    Location:
    Nj
    Thanks so much!
     
  18. Rooster53

    Rooster53 Well-Known Member Premium Member

    Messages:
    1,852
    Likes Received:
    723
    Trophy Points:
    113
    Location:
    North, FL
    Could have been when the diode block burnt - did they tell you which fuse? From your pic it looks like the diode for the headlight relay.

    There not super cheap so I would follow k-moe's advise and use a meter to determine which diode burnt, and not assume it was caused by the nut shorting something. From there you can check out the associated circuitry to reduce the chances of burning the new one, which will happen in a flash if the problem has not been corrected. They can be repaired, but will not look as nice as original.

    The chart is for the Yamaha pocket tester, you will likely be using a DMM set to the diode check function so a forward biased diode will read around .45 to .6 and open when the leads are reversed. The burnt diode could read either shorted or open in both directions.

    upload_2019-9-21_15-8-53.png
     
    k-moe likes this.
  19. XJ550H

    XJ550H Well-Known Member Premium Member

    Messages:
    13,199
    Likes Received:
    3,854
    Trophy Points:
    113
    Location:
    Great North Woods
    if the latching diode failed in the headlight relay your diode block would be supplying power to headlight full time and would burn out block.
    that would be D3
    D2 runs the starter safety relay and sidestamd relay safety circuits.
    D1 and R are what controls the oil light. oil light test function (D1) oil light when low on oil (R).
     
  20. Trvpstar

    Trvpstar Member

    Messages:
    31
    Likes Received:
    2
    Trophy Points:
    8
    Location:
    Nj
    I’m going to go ahead and assume my issue is the diode block, headlight wasn’t turning on when the bike actually ran (carb spray) and would want to almost start with the diode connector plugged in. I then unplugged the connector and tried to start and the bike just cranks no slight signs of wanting to start so hopefully it was this diode. Like I said before I don’t think it’s anything else because when I opened the headlight bracket one of the nuts was melted into the diode. It must’ve shorted itself out because of the nut
     

Share This Page