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    3.5 cylinder bike

    3.5 cylinders, Odd number of cylinders for a bike ehh? so heres the story,

    1982 GS1100E with 22000 miles on the clock. I cleaned the carbs fired her up and and the headers got hoton 3 and 4 only slightly warm on 2 nothing on 1. so, i pulled the carbs cleaned them again, put in some new valve seats and needles, fired her up and 1, 3 and 4 headers were hot 2 is still only slightly warm to the touch. so here we are I have spent 5 hours
    reading old posts and I am out of ideas....please help! [-o<

    here's what i've done.

    switched number 2 and 3 plug wires no change
    switched number 1 and 2 plugs no change
    Based on my rather limited knowledge that should rule out ignition (correct me if im wrong)

    number 2 is getting fuel the plug is wet

    idle is very irradic raising and lowering, seems like number 2 might be kicking on and off intermittantly

    compression is about equal accross the board, a bit low but the engine was cold so that could be fine

    I haven't checked the valve clearance yet, Im not thinking this would cause these symptoms and i wanted to have her runnin on four before i did that. (correct me if im wrong)

    any and all help is greatly appreciated, im stumped.
    thanks,

    nick

    #2
    Originally posted by crazedfooter View Post
    3.5 cylinders, Odd number of cylinders for a bike ehh? so heres the story,

    1982 GS1100E with 22000 miles on the clock. I cleaned the carbs fired her up and and the headers got hoton 3 and 4 only slightly warm on 2 nothing on 1. so, i pulled the carbs cleaned them again, put in some new valve seats and needles, fired her up and 1, 3 and 4 headers were hot 2 is still only slightly warm to the touch. so here we are I have spent 5 hours
    reading old posts and I am out of ideas....please help! [-o<

    here's what i've done.

    switched number 2 and 3 plug wires no change
    switched number 1 and 2 plugs no change
    Based on my rather limited knowledge that should rule out ignition (correct me if im wrong)

    number 2 is getting fuel the plug is wet

    idle is very irradic raising and lowering, seems like number 2 might be kicking on and off intermittantly

    compression is about equal accross the board, a bit low but the engine was cold so that could be fine

    I haven't checked the valve clearance yet, Im not thinking this would cause these symptoms and i wanted to have her runnin on four before i did that. (correct me if im wrong)

    any and all help is greatly appreciated, im stumped.
    thanks,

    nick
    Check the spark coming off the ingition wire in a dark garage or another equally dark place to ensure you're getting spark. Sounds like one of your coils is gone mate

    Comment


      #3
      would that affect only one cyl at a time? i thought it would get both or none. shouldn't the problem follow when i switch plug wires?

      thanks for the help keep it comin.

      Comment


        #4
        What did you do when you cleaned the carbs? Did you fully break them down and replace all the o-rings?
        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


          #5
          This sounds like it could be a leaky diagphram in your petcock. It's easy to check. Just attach a long, clear tube to the petcock instead of the vaccum hose, and suck on it. If you eventually get gas in the tube, you know you've found the problem. Use a LONG tube so you see the gas long before it enters your mouth or lungs!

          The leaky diagphram would allow gas to enter the #2 cylinder and flood it out (making the spark plug wet). If this turns out to be the problem, change your oil.

          Comment


            #6
            While your at it check the float height in your carbs. I don't know what measurement they need to be set at but if the second cylinder's float is off it could be causing you to flood the cylinder. I think that was happening to a guy on here till he realized the floats were way off

            Comment


              #7
              Ness, yep fully broke down new o rings all around.

              Bizz, no dice, just ran down and tried it and all i got was some gas smellin air in my lungs....pleasent.

              floats are all pretty durn close, i just used a ruler but they were all set to specs.

              thanks for the suggestions

              nick
              Last edited by Guest; 11-29-2007, 12:17 AM.

              Comment


                #8
                Yeah funny thing is that thats what the guy said he used the first time around and then he went back with a caliper and they were off by a few millimeters

                Comment


                  #9
                  this may be a stupid question but how do you use a caliper to take that measurement? I am not opposed to goin an buyin one if it will take care of the problem but i can't picture how you would maneuver a set of calipers to measure the float height. sorry if this is a dumb question but i don't get it:?

                  thanks

                  Comment


                    #10
                    Use the back side of the caliper - where the slide sticks out. I seriously doubt the problem is caused by float height being off though. The problem sounds like something fundamental; either a weak spark or you sill have a plugged pilot jet or idle circuit in that #2 carb. The reason I asked about the carbs is because we read about people "cleaning" their carbs multipul times here in the Technical forum only to learn later that they never verified the pilot jets are open. Frankly, if the carbs are truely as clean as you claim, the problem must be spark.

                    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


                      #11
                      possibly somewhat related question, would low compression on a cyl cause the symptoms i am having. i looked at my compression numbers and the #2 was only at 90 on a cold engine. i may do a valve job to see if it helps but what do you guys think.

                      i would think the header would still heat up even with low compression but i am not to experienced with the likes of compression stuff.

                      thanks,
                      nick

                      Comment


                        #12
                        Originally posted by Ironriot View Post
                        While your at it check the float height in your carbs. I don't know what measurement they need to be set at but if the second cylinder's float is off it could be causing you to flood the cylinder. I think that was happening to a guy on here till he realized the floats were way off
                        yeah...me...lol wasnt causing it not to fire tho..and yeah from my understanding, its all or nothing on a coil..

                        Comment


                          #13
                          Originally posted by crazedfooter View Post
                          this may be a stupid question but how do you use a caliper to take that measurement? I am not opposed to goin an buyin one if it will take care of the problem but i can't picture how you would maneuver a set of calipers to measure the float height. sorry if this is a dumb question but i don't get it:?

                          thanks
                          Get yourself a set from autozone or something..mine were decently priced..i think 35 bucks or around there...there will be a depthfinder that comes out of the end...set it to your needed float hight and set the point of the depth finder on the gasket mating surface and the actual bottom of the caliper should touch the top of your float..if the float is higher or lower it needs adjusted...as a matter of fact, im about to quadruple check mine here in a few minutes before i put them back in tomorrow, so ill snap some shots and post em up for you...

                          Comment


                            #14
                            Originally posted by crazedfooter View Post
                            possibly somewhat related question, would low compression on a cyl cause the symptoms i am having. i looked at my compression numbers and the #2 was only at 90 on a cold engine. i may do a valve job to see if it helps but what do you guys think.

                            i would think the header would still heat up even with low compression but i am not to experienced with the likes of compression stuff.

                            thanks,
                            nick
                            Also..did you check your plug wire caps? They are good for going bad, and that could very well be your problem...just a thought.

                            Comment


                              #15
                              Here are some pics..

                              The calipers...cheapies, but they'll do the job...


                              This is the depth finder that comes out of the bottom when you move the caliper gauge..


                              And here is how ive always been shown to measure mine...yours will be a bit different if they are CV type carbs, mine are mechanicals, with a different float set up...



                              Any questions, just ask!!

                              hope it helps

                              TCK

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