Announcement

Collapse
No announcement yet.

Help please, fuel in airbox!

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Help please, fuel in airbox!

    She started ok this morning so off I went. Went round a roundabout and opened her up and she started missing so I stopped and she stalled. Had a look round, everything still looked ok. Started her up, eventually, but still missing, rode her home slowly, about 2 miles and she stalled as I pulled in the drive.
    Checked the compression and it is between 130-140psi across all 4. Plugs 1 & 2 were black, 3 & 4 brown. Cleaned and gapped the plugs, checked spark was ok and put them back in. Started her up and got petrol out of the air box drain pipe!
    Took tank off and carbs, butterflies free, slides rise and fall slowly when you lift them and floats free. Petcock is ok as the tank was disconnected but full of fuel while I did some work on her and it did not leak.
    Put carbs back on without air box, primed them and she started perfectly. Tick over about 1200 and did not miss a beat. Gave her some gas, instant response and then idled fine.
    The carbs had been stripped about a month ago and and new o-rings fitted (the ones that are recommended on this site) and I have done about 400 miles since then.
    Before I put her back together totally, any ideas?
    Cheers.
    Last edited by Guest; 05-03-2014, 06:18 AM.

    #2
    Best measure fuel level in each carb. Maybe one, or a couple, of the float needles are leaking. If the float needle spring is weak the fuel level may be higher than desired and causing the overflow. Sometimes fuel backflows down the vacuum line to the petcock too. Some clear tubing there will tell the tale.

    Good luck
    Ed

    To measure is to know.

    Mikuni O-ring Kits For Sale...https://www.thegsresources.com/_foru...ts#post1703182

    Top Newbie Mistakes thread...http://www.thegsresources.com/_forum...d.php?t=171846

    Carb rebuild tutorial...https://gsarchive.bwringer.com/mtsac...d_Tutorial.pdf

    KZ750E Rebuild Thread...http://www.thegsresources.com/_forum...0-Resurrection

    Comment


      #3
      "....Petcock is ok as the tank was disconnected but full of fuel while I did some work on her and it did not leak."

      Don't bet on it now-stuff happens! bad petcock with dribbling fuel inlet seats means trouble. Recheck petcock
      1981 gs650L

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

      Comment


        #4
        Stuck float and float needle maybe too. Take a sniff off the oil fill cap to see if theres any in then oil. Sometimes just a few taps on the bowls with a wrench cures that.
        MY BIKES..1977 GS 750 B, 1978 GS 1000 C (X2)
        1978 GS 1000 E, 1979 GS 1000 S, 1973 Yamaha TX 750, 1977 Kawasaki KZ 650B1, 1975 Honda GL1000 Goldwing, 1983 CB 650SC Nighthawk, 1972 Honda CB 350K4, 74 Honda CB550

        NEVER SNEAK UP ON A SLEEPING DOG..NOT EVEN YOUR OWN.


        I would rather trust my bike to a "QUACK" that KNOWS how to fix it rather than a book worm that THINKS HE KNOWS how to fix it.

        Comment


          #5
          I have just ordered some clear vacuum hose and I am going to replace the spark plugs and caps. When I checked the plugs last week, they were all brown. No fuel in the oil that I can see/smell. Just went out to the garage and she struck up first time on choke after standing for about nine hours and then idled ok (a bit low about 1000, but the airbox is still off). I am fed up taking half an hour to get the carbs back on, so I am thinking of fitting Pod Filters, she has a Motad 4-1 exhaust, if I were to fit pod filters, I presume I would need to change the jets, what size and what else do I need to do? If I am going to strip the carb down again I might as well do this as well!!

          Comment


            #6
            Well I stripped the carb down totally. Main jet and pilot are stock. Blasted everything with carb cleaner and inspected all the jets with a torch etc, all seemed ok, one float measurement was a little low at 20mm, the other 3 were approx 22mm. So I have set them all at just over 22mm and put it all back together. Double checked the fuel line route and used a bit of clear tube I had (until the new stuff I ordered arrives) for the vacuum line so that I can see if I get any fuel in it.
            I put her back together and went for a ride, never missed a beat in 50 miles, the she started missing, fantastic I thought, looked at the speedo and put her on reserve and off she went again!!
            Happy chap.

            Comment

            Working...
            X