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1982 Yamaha XJ 650 Maxim gas issues

Discussion in 'XJ Technical Chat' started by Dakota Wallace, Nov 14, 2017.

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  1. Dakota Wallace

    Dakota Wallace New Member

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    okay so I recently just rebuilt the carburetor to my bike. I’d have to check what jet was placed where in my carb I’m pretty sure the bigger one was closer t the float. The only thing that I did not put new in it was the drain plug on the bowl and the float it’s self. But I’m able to actually blow into the fuel line and I mean it goes in. I also have my vacuum line hooked up. I used an electrolysis to clean my gas tank so I know that’s all good. The valve it’s self I cleaned as well. Please help I’m stumped on this. When I rewired my bike I used a simple wiring method if that makes a difference
     
  2. XJ550H

    XJ550H Well-Known Member Premium Member

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    unless your carb bowls are full air will flow into fuel line

    air jets proper location jets.jpg

    Main FUEL Jet Size: #110
    Pilot FUEL Jet Size: #40
    main jet goes in center of carb on emulsion tube with slide needle above it.

    floats installed upside down?

    what exactly is your fuel problem ?
    no fuel to the bowls?

    did you wet set the floats?
    Setting the fuel levels

    do you have a picture of your wiring diagram?
    eQNlgxq.jpg m1csRY7.jpg
     
    Last edited: Nov 14, 2017
  3. Dakota Wallace

    Dakota Wallace New Member

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    Well I guess getting fuel is no longer a problem, I left it on prime all night to let it flow in. Problem now is that when it starts it revs and idles EXTREMELY high. I have to shut it off real fast as I don’t want to blow the engine.
    I’m dead certain I placed the jets in the right order when I rebuilt it as I took one off cleaned the area and put the matching item where it was. I’ve tried to screw the adjustment screws all the way in. I’ve tried the general 1- 2 turns back out. and I’ve tried them 5 turns out like the original were. And even farther out than the 5. I’m so stumped.
     
  4. Dakota Wallace

    Dakota Wallace New Member

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    The wiring diagram I used was the basic one in the green picture
     
  5. Dakota Wallace

    Dakota Wallace New Member

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    Have not got it to start since last stated
     
  6. Dakota Wallace

    Dakota Wallace New Member

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    What way does the float go. I have them with the higher part facing down. Toward the needle
     
  7. Rooster53

    Rooster53 Active Member Premium Member

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    Up vs down can be confusing - refer to the link that XJ550H provided in post 2 and page 7 shows the correct orientation.

    The mixture screws are going to have very little affect on idle speed. More likely is either the idle speed screw located between carb 2 and 3 is too far in, or the throttle cable is not installed correctly holding the butterflies open. Some members have even accidentally swapped the choke and throttle cable by mistake.

    Verify the idle speed screw is in contact with the stop linkage and then back off the idle speed screw knurled knob to where it just touches the stop linkage, then maybe CW a half turn.Verify with the throttle released there is slack in the throttle noted by both the feel at the grip and the slack in the cable at the carb mounting point.

    To this standard?

    http://www.xjbikes.com/forums/threads/in-the-church-of-clean.14692/

    Which also covers the initial bench sync to get things close.
     
  8. Dakota Wallace

    Dakota Wallace New Member

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    I was able to get the bike to stop idling so high. Sometimes I am able to start her without starting fluid. I don’t see a problem with the throttle cable or adjuster, sometimes it seems like she wants to start easier when connected to a battery charger, but everything gets the power it’s supposed to without t also. I appreciate y’all patience with me
     
  9. cgutz

    cgutz Well-Known Member Premium Member

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    Starting with a battery charger or jumper cables connected could be a sign of weak battery causing low voltage while cranking. You may have just enough voltage to get some spark, but below about 10 volts the TCI won't fire. When my bike cranks but doesn't start, then starts when battery charger is connected, it is a sign of a weak battery as the charger is keeping the voltage up enough for the ignition to spark properly.
     
  10. Dakota Wallace

    Dakota Wallace New Member

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    Could this actually keep it from running after it has started though? I can get it to run for a good 5 seconds before dying out. Also, the gas tank is NOT full. No where near. Honestly just enough so that I could get it to start (16 oz approx) could this be keeping it from staying running?
     
  11. k-moe

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

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    You need at least 1 gallon in the tank. There is a volume of fuel at the bottom of the tank that the petcock will not drain.
     
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  12. Dakota Wallace

    Dakota Wallace New Member

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    Okay so I took your advice and added a little over a gallon to the tank, still no avail. Sometimes I have to use the starter fluid still but not that much. The bike still runs for only 3-5 seconds before dying out. I noticed that while it is running giving the bike throttle does nothing to RPM. Now I don’t have a tachometer on it but I can tell when I do I’ve it throttle it makes no difference. I am dead positive the cable is the right one I’m using (thickest cable for clutch, middle thickness for throttle cable, and the smallest cable for the choke. If this changes or gives you an idea on the problem. Also if by chance can you show me how far down the needles for the choke sit down. I noticed mine do not sit all the way down and have a slight gap and play in the whole linkage before they move up when activating choke.
     
  13. Dakota Wallace

    Dakota Wallace New Member

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    Also I should have mentioned, when I rebuilt the carb the needles under my floats weren’t exactly the same. The size and all is good and they have the spring on the back. The only thing they did not have was the wire piece on the back that hooks to the float. Oh and the adjustment screws for the idle had a clear tubing on them but my original ones did not so I took those off thinking they were just to protect the needle tips. If any of this could be a problem let me know. I am providing a picture to the carb kit I bought
     

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  14. hogfiddles

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

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    Can you confirm that you see the BUTTERFLY SHAFTS rotating when you twist the throttle? Easy to do.....watch the end of the carb rack and see if you see the c-clip rotate when you twist. If it does, the cable is hooked to the right place.

    If it doesn't, then pull the enricher lever....does it move now?........cables hooked up backward.

    Is your vacuum line hooked up to the manifold Port AND your petcock?

    What happens if you set the petcock to PRI for two minutes before trying to start?
     
  15. Dakota Wallace

    Dakota Wallace New Member

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    All of those things are correct and setting it to primefor two minutes and starting still causes bike to die off after 5 seconds
     
  16. hogfiddles

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

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    Put the bike on the center stand

    Put a different line on the petcock and see if gas pours through into a container
    .on PRI
    .on ON, when you're cranking the engine (or carefully sucking through a surrogate vacuum
    line)

    Put the regular fuel line back on, pull it off at the fuel T......got a good stream of fuel€

    Put some drain hoses on the bowls, run them into a clear container
    open the drain screws
    Do you get 4 good streams of gas pouring through?
     
  17. Dakota Wallace

    Dakota Wallace New Member

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    All of that is good as well
     
  18. hogfiddles

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

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    1. Check the airbox to make sure there's no mouse nest blocking the air

    2. Open the filler cap in case the vent is plugged and creating a tank vacuum
     
  19. hogfiddles

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

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    I am simply trying to either find or rule out a fuel issue at this point. Once we can determine that fuel supply IS or IS NOT the issue, then we can look elsewhere, but I don't want to go shooting in the dark at a million things at once. If you do it that way, then sometimes problem will stop, and you'll have no clue which of the attempts solved it.

    So, we're isolating fuel issues first. Then we'll issue something else......etc......
     
  20. Dakota Wallace

    Dakota Wallace New Member

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