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    Having problems starting the bike

    I put a dynatek ignition on it and it ran fine but there was fuel leaking out the intake when the petcock was on prime and not running.This year I went to start it up and it finally fired up, but ran bad. I removed the air filter and stuck my hand in the intake to slow the air down and it ran great on the stand. I cleaned the air filter and it wouldn't run after that.I have pulled the valve cover and checked the valves. They are all in spec. I need to put it back together. I am guessing I will have to pull the carbs and check to see what was causing the gas to leak. The other thing I was wondering about would be the breather oil separator.I think this is what it is called. My bike does not have it but other bikes do according to the parts picture. I remember seeing someone ask about it along time ago but can't find anything. If my bikes parts picture doesn't show it, I'm guessing it didn't have any? Back to the first question any ideas of what may be wrong? Where should I start. The plugs were wet when I took them out to check the valves but it wasnt starting so maybe it was just a bit flooded? Thanks for any help.

    #2
    Head on over to http://members.dslextreme.com/users/bikecliff/ and look for the CV carb rebuild tutorials. Follow them to the letter. If gas was flowing out of the intake, one or both of the fuel valves is leaking, or a float or two is stuck. Smell your oil and and if it reeks of gas, change it out.

    Can you show us which breather oil separator you're talking about? The wire mesh things in the little compartment in your valve cover? To my knowledge, all GSes should have them there...
    Charles
    --
    1979 Suzuki GS850G

    Read BassCliff's GSR Greeting and Mega-Welcome!

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      #3
      The petcock should only be on prime long enough to fill the bowls, less than a minute. You should run it either "on" or "res", that way fuel is only flowing when there is vacuum from the engine (i.e. when it's running). Leaving it on prime can overpower your float needles and cause gas leakage.
      Regards,
      Jason

      ______________________________________
      1978 Suzuki GS750 EC

      Comment


        #4
        Did you have the bike in storage? Did you put a fuel stabilizer in the tank?

        If the bike has been sitting for a few months without a fuel stabilizer the carbs will probably be gunked up and need a clean.
        Current:
        Z1300A5 Locomotive (swapped my Intruder for it), GS450 Cafe Project (might never finish it....), XT500 Commuter (I know - it's a Yamaha )

        Past:
        VL1500 Intruder (swapped for Z1300), ZX9R Streetfighter (lets face it - too fast....), 1984 GSX750EF, 1984 GSX1100EF (AKA GS1150)
        And a bunch of other crap Yamahas....

        Comment


          #5
          Originally posted by CrazyCloud View Post
          The petcock should only be on prime long enough to fill the bowls, less than a minute. You should run it either "on" or "res", that way fuel is only flowing when there is vacuum from the engine (i.e. when it's running). Leaving it on prime can overpower your float needles and cause gas leakage.
          In a word: no. There is no "overpowering" the floats.

          While I agree that one should never leave the petcock in the prime position, a fuel leak would require that either a carburetor float is stuck or that one of the needle/seat assemblies is leaking.

          If the needle/seats don't leak and the floats are free leaving the petcock in the prime position would do no harm at all. Putting the petcock in the "Run" position is simply a safety backup.

          Comment


            #6
            Originally posted by JayWB View Post
            In a word: no. There is no "overpowering" the floats.

            While I agree that one should never leave the petcock in the prime position, a fuel leak would require that either a carburetor float is stuck or that one of the needle/seat assemblies is leaking.

            If the needle/seats don't leak and the floats are free leaving the petcock in the prime position would do no harm at all. Putting the petcock in the "Run" position is simply a safety backup.

            Of course needle valves rarely ever leak ; as they are made of rubber that virtually immune to aging

            With even with the remote possibility that the needle valves might leak, the down side is only that the crank case might get filled with gas or better yet, hydraulic lock in one of the compression chambers where you bend your crank. Not to worry as float valves rarely rarely ever leak even the slightest . Of course your OP float needles are brand new.; right?

            Comment


              #7
              Originally posted by posplayr View Post
              Of course needle valves rarely ever leak ; as they are made of rubber that virtually immune to aging

              With even with the remote possibility that the needle valves might leak, the down side is only that the crank case might get filled with gas or better yet, hydraulic lock in one of the compression chambers where you bend your crank. Not to worry as float valves rarely rarely ever leak even the slightest . Of course your OP float needles are brand new.; right?

              Okay, I'll bite. Are you trying to make a point? What is it?

              Comment


                #8
                I have rebuilt the carbs before. They seem to be okay other than the leaking. I put it on prime that time, to fill the bowls up, and forgot to turn it back. That was last fall after it set for a month or so.I am doing a complete service and have changed the oil. I will check to see if the bowl gaskets are causing problems.I heard that they can hit the float because they are a bit bigger. I used the rebuild kits on ebay. That was a few years ago. Was not a problem until last fall. I still have to change the drive oil. Thanks for the ideas though. I am thinking about a new air filter. I would put pods on it but I dont have the patience to jet it. I have never done plug chops yet, maybe that would help with the troubleshooting. I am not sure how to seal my air box but it seems to do okay around the edges. I could try to put some foam weather stripping to get it really sealed, or maybe some tape? One thing that does need done would be sync the carbs. It has run good before like it is, just does not like to start very well. If I ride it to work every day it runs great. I was just trying to get everything serviced and get it up and running after the whole voltage regulator thing. I lost a lot of ride time last year trying to get it fixed. Thanks for the ideas though.

                Comment


                  #9
                  Can you show us which breather oil separator you're talking about? The wire mesh things in the little compartment in your valve cover? To my knowledge, all GSes should have them there...
                  Yes it is the wire mesh things. There are none in the breather top or bottom. If you look in the part diagram it does not show them on my bike but other bikes have them. I'm not sure what they are for? There are spots for them.

                  Comment


                    #10
                    Originally posted by scrapper View Post
                    Yes it is the wire mesh things. ... I'm not sure what they are for? .
                    They are there to help separate the oil from the vapor that gets pulled through the hose. Oil will collect on the mesh and drip back into the crankcase, leaving just the air to get drawn through the airbox, then through the carbs.

                    .
                    sigpic
                    mine: 2000 Honda GoldWing GL1500SE and 1980 GS850G'K' "Junior"
                    hers: 1982 GS850GL - "Angel" and 1969 Suzuki T250 Scrambler
                    #1 son: 1986 Yamaha Venture Royale 1300 and 1982 GS650GL "Rat Bagger"
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                      #11
                      So the leaving petcock on prime was last fall, but you're dealing with that now by changing oil filter/oil. Did bike sit over winter with old gas ? Bike should not be hard to start either from cold or hot- your enrichment system (the "choke") might be clogged. Each fuel bowl has small feed tube that supplies fuel to carb throat- old gas can gunk this system up .
                      i wouldn't worry about breather mesh filter too much- mine is missing too. A stainless steel pot scrubber would do if you are fussy.
                      1981 gs650L

                      "We are all born ignorant, but you have to work hard to stay stupid" Ben Franklin

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                        #12
                        It has always been a pita to start unless I'm riding everyday or at least 3 to days a week. It would not start though the last time I tried.It did run fine just before that. The plugs were wet. I was thinking fuel or spark has to be the problem. I was thinking the air fuel mix may be off or something? I will start looking for problem after I put it back together. Thanks for the help. I really hate putting the carbs back on.Taking them off is really not to bad.I dont think the gas could be real bad it was running on it fine for awhile.

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