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Hello from new member + carb help needed [cracked housing]

kml.krk Jan 11, 2013

  1. kml.krk

    kml.krk Member

    the owner is checking for fuel in oil as we speak!!
  2. kml.krk

    kml.krk Member

    there IS fuel in oil. He is supposed to replace oil.
  3. wuputt

    wuputt ZL-OA Co-owner Staff Member Administrator Super Moderator Technical Author Supporting Member

  4. kml.krk

    kml.krk Member

    Fuel must have gotten to oil before carbs were fixed by Rick. The mixture screw housing was broken off and mixture screw was missing.
  5. salamander

    salamander Active Member

    That by itself shouldn't resuilt in the carbs overflowing into the cylinders -- the mixture screws don't change once set and should never be closed to gas flow. Assuming the carb floats are set at the right hieght and the needle valve is sealing right, the only thing I can think of is that the bike is not sitting level. If it's sitting with the front wheel below the back by far enough, everything in the carbs can be set right, but you could still get gas flow into the engine intakes. Could this be the case?
  6. jmassengill

    jmassengill Supporting Member Technical Author

    Ok, now I'm scratching my head about what the problem might be.......:icon_scratch::icon_scratch:
    i'm going to have to walk around and give this one a good think.
  7. kml.krk

    kml.krk Member

    Just realized VERY important detail.
    When we run the bike last night with the fuel tank off the bike we plugged the fuel hose BUT we left the vacuum hoses opened (two that merge to one and go to petcock). This was the ONLY moment when the bike run correctly.
    With that being said it seems that bike is not getting enough air. The fuel may actually be correct...

    Jerry is supposed to change oil and do a test run with air box not connected to the carburetors to provide as much air as possible.

    Question: could there be anything blocking the air flow flowing into the carburetors?
  8. Bozang1

    Bozang1 Well-Known Member

    See, there's still hope for you MM....:laughing7:
  9. R. J.

    R. J. Supporting Member


    :hello: Gas in oil has happened to me in one of my old duel sport bike & one of my ATVs. due to floats sticking. Air box filled up with gas then running into motor through the breather. My duel sport bike did not have an off position. So when my petcock failed the gas entered the motor. I checked the oil through the window before I rode. I thought it was just a little over filled. Rode it about 2 miles & the clutch started chattering so I pulled over opened the oil fill hole & could smell gas. I ran some cheep oil through it 3 times for a few miles each to ensure all the gas was out. R. J.
  10. Bozang1

    Bozang1 Well-Known Member

    Ok, so we are basically narrowing it down to a problem before the carbs OR an air cleaner issue. What shape is the air cleaner in? Is it clean? Is it appropriate sized for the bike (I think you said someone switched it) if it's not big enough or clogged it will cause it to pull more fuel.
    Try this: with everything hooked up, pinch the fuel line a little coming from petcock until you feel it's running right, then rev it up. Does it rev past the 5000 RPMs that you spoke of earlier?
    And just to recap: with air cleaner hooked up and hose between carb and petcock blocked (not the one the fuel comes through, the other one) and auxiliary tank hooked up it runs/revs fine? If so, that will rule out the air cleaner and the focus would strictly be tank and or petcock (or that hose that I just told you to block)
    If it runs ok like that then forget about valves and floats and air leaks etc...Boz
  11. kawazee

    kawazee Member

    Right, back off the whole thing. Leave it for one or two days alone and do not think about it. Go out and have some life:headbang: It is amazing how much a clear head can see. You might not see the mountain from the tree.

    Start over: Put the tank next to the bike, hook it up to the carbs with a longer fuel line (check or re-check if your petcock works). You should get a constant fuel flow on PRI. Wait a minute or so until the bowls fill and start it up.

    So if it starts and runs like before, you are haf way there. I don't know if you have mentioned if you used the choke or not, but I assume you did.

    If it runs and warms up, see if it ides at 1200 -1300. In any case, let it run for a few minutes and see if it starts on the button. If you still have the fuel smell, disconnect the fuel line (don't forget to turn the petcock back to ON otherwise you'd be sitting in gasoline) and pull the carbs. Observe if fuel dripping form any of the intake boots and see if any of the intake rubbers are wet from gas. If it is dripping or the intake rubbers are too wet your bowls are overflowing. I know you had the carbs rebuilt, but despite that if you had any dirt in the tank or the line you connected, you could have easily contaminated the carbs and either the float valves sticking or the float hight is not set right (17 mm I believe plus or minus 0.5) Also, if this is occuring, you should see fuel dripping from the air intake side. That is how you get your oil contaminated. Anyhow, nothing should be dripping wet.

    What I also do is remove all the spark plugs and with compressed air I blow out the cylinders (use a can of duster if nothing else) and dry the plugs. Set the gap at 0.6 rather than 0.7 mil. dry the plugs and put em back in. Check if you have consistent sparks on each cylinder. Bad coil is not unknown to the ZL600. If you have just n cylinder misfiring that can build up fuel in the exhaust causing backfiring and such.

    If all is good and the carbs are fine, see if you get a constant idle set at 1600 (adjust the idle screw). Despite the fact that you won't have an air tight system, idle at 1600-1700 should be pretty consistent. If not, you need to re-adjust your pilot screws (or fine tune it if you will). the main jets come into effect at about 3000 rpm, so the fuel ratio is mixed by the pilot screws below that.

    Now, if you happy with that, you can start putting the bike back together. It is a pain with the airbox on the ZL, but can be done. Make sure all boots seat properly. it is so easy to miss just one in the middle, and will not be easy to see it either. Use a strong flash light to check it from every angle. Yous hsould feel it's right anyhow. Dn't frget about the bottom, crank vent either and the filterbox by the fender. All should fit tight.

    Once done check and double check and tighten all screws/bolts. on both side carb and intake side. Hook the tank back on again externally and see if it runs. Fingers crossed should. But if it doesnt check:

    are the vacuum hoses properly capped?
    any of the carb boots leaking?
    Are the carbs synchronised?

    Handy tool to check the vacuum leaks is to get some starter fluid and spray it on the boots while the engine is running. you should be able to detect leaks easily, make sure though you have adequate illumination.

    anyhow, be patient and don't let frustration over take you. If you cannot win today, you'll win tomorrow. I might not be right with everything I've said but hopefully you got some pointers out of it. Just take it easy.:pistols:
    Last edited: Feb 21, 2013
  12. Bozang1

    Bozang1 Well-Known Member

    What's the good word??
  13. prfixer

    prfixer Senior Member Supporting Member

    Can you post a picture of how you have the carbs setup on the bike?
  14. kml.krk

    kml.krk Member

    Taking kawazee's advice and backing off for a while.
    I can't post picture right now as this isn't my bike ;)
    I advised the owner to change oil and try running bike without air box to see if there is any difference.

    For now THANK YOU ALL VERY MUCH for all your help. If the owner decides that he wants to try to fix it in house I will go over everything posted here so far and help him troubleshoot it. For now I can't do much more. I will keep you posted if there is any progress. I'm very curious to find out what is going on with that bike!
    Thank you again for all the input and ideas that you have provided!
  15. paulfun

    paulfun "King Of The 1/4mi (Internally Stock)"

    I have one question While the carbs were off being done did you drain the tank and clean it out before re-installing the carbs???
  16. madmanncr500

    madmanncr500 Well-Known Member

    Just what i said in #39!!! I'm betting it"s got crud back in the carbs....?????
  17. kml.krk

    kml.krk Member

    Tank was cleaned and checked for rust couple weeks before carbs were sent out to Rick.
    Even if it wasn't super clean would it really clog all 4 or most of float bowls immediately after starting? I was thinking that it would run properly for at least few minutes before clogging float bowls and making the bike run like crap...?
    Last edited: Feb 22, 2013
  18. Blue-Grass-Tornado

    Blue-Grass-Tornado _________________________ BANNED

    I assume the petcock filter is in good shape too? I would have been half tempted to throw an inline visible filter in it also, just as a safeguard, I have one built into my "test" gasoline source, and it's coming right out of a gear oil bottle! You never know what kind of junk can end up in there, always better to be safe than sorry.
  19. kml.krk

    kml.krk Member

    Just got a message from owner that one cylinder is not firing. He basically gives up and wants to take the bike to the local mechanic. Anybody wants to guess how much $$$ will he waste? ;) what are even the chances that a mechanic will nail all the issues at once?

    My guess is $450 and bike will still not run 100%...

    I really hope that I'm wrong...!

    Thank you all for input and sharing your knowledge. At this point I'm backing off and won't be getting involved with fixing this bike anymore. I tried my best to help and you did too.

    Ride safe!
  20. wickedzl900

    wickedzl900 Senior Member Supporting Member

    one cylinder not firing, if it were coils or pick up sensor it would be 2 cylinders, bad plug wire? if that mechanic digs into the carbs and destroys them i am out also...i maybe get 1 or 2 sets back a year out of 80+, most of the time it is from a so called "mechanic", the carbs that comeback are broken, something stripped or parts are robbed ... never heard the results of the compression test? also were the wires new? i also told kamil to send those back if problems persisted ,a week ago,,,rick
    Last edited: Feb 25, 2013

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