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    High rev at idle ?

    I’d just like to put out some feelers for which direction to look concerning my high rev at idle problem;
    Bike ran ok until warmed – then it would stall, so I removed and cleaned the carbs, reassembled and reinstalled them without trying too hard to sync them properly (ran o.k. before and I didn’t disassemble the slide assembly anyway.) but the slides looked pretty well equal as I put it back together.
    Ran it for a while (couple of miles) with out any idle problems, then had to fix the tank leak:roll: … now it runs well and strong except that it won’t come down off of 2500 rpm. This seems to be progressive. Oh, and there’s a little hiccup while it’s warming up… and I can sometimes see a little puff of pressure come out between the No. 1 intake boot and No.1 head when it hiccups like that. (Hmm..?? valve adjust? or timing? he thinks as he is writing)
    With four carbs pulling potentially different pressures, fuel amounts, and temps I get a little boggled in the brain. If one carb is pulling too much fuel, what is happening inside the others?
    Where do I start? Pulling the tank off is easy now (practice made perfect) but I’d HATE to have to pull the carbs again.., yet. License test in two weeks.
    Just askin.

    #2
    Fix your leak at the intake boots, that's most likely causing your high idle! Change them all while you have the carbs off!!!!
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    Comment


      #3
      While your there get ride of those phillips screws and get the 6mm allen heads and torque to 6 to 8 ft.lbs Be sure to put some high temp grease on your 0-rings to help hold them in place in the intake boot before mounting.

      Comment


        #4
        Ironically, I just found a set or two of those bolt kits on eBay. Where to find the boots tho?

        Comment


          #5
          The boots can be bought from the dealer...but before you invest money in the boots, check out the O rings. That little seal can cause a lot of problems.
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          Comment


            #6
            Yup, there is a large diameter O-ring between the head and boot. Air leakage past the O-ring is VERY common and will lead to a high hunting idle among other problems.
            Ed

            To measure is to know.

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              #7
              Originally posted by justin caise View Post
              I’d just like to put out some feelers for which direction to look concerning my high rev at idle problem;
              Bike ran ok until warmed – then it would stall, so I removed and cleaned the carbs, reassembled and reinstalled them without trying too hard to sync them properly (ran o.k. before and I didn’t disassemble the slide assembly anyway.) but the slides looked pretty well equal as I put it back together.
              Ran it for a while (couple of miles) with out any idle problems, then had to fix the tank leak:roll: … now it runs well and strong except that it won’t come down off of 2500 rpm. This seems to be progressive. Oh, and there’s a little hiccup while it’s warming up… and I can sometimes see a little puff of pressure come out between the No. 1 intake boot and No.1 head when it hiccups like that. (Hmm..?? valve adjust? or timing? he thinks as he is writing)
              With four carbs pulling potentially different pressures, fuel amounts, and temps I get a little boggled in the brain. If one carb is pulling too much fuel, what is happening inside the others?
              Where do I start? Pulling the tank off is easy now (practice made perfect) but I’d HATE to have to pull the carbs again.., yet. License test in two weeks.
              Just askin.
              90% of the time a hanging high idle is a result of an air leak or way mis adjusted air screws (also too lean).
              After reading all your comments simply sounds like you STILL have dirt in your carbs. Like I comment to TONS of people with your exact same behavior scenario, you need to have your carbs DIPPED to completely clean all the tiny internal carb passage ways. The simple "Gummout and air blast" method usually doesnt work completely. My carbs looked great, but I had a non-idling #3 cylinder so I had my carbs dipped, problem solved. And a great bonus after a 4 hr dip session your carbs will look like absolutely brand new (externally) as the fluid is slightly corrosive and removes all the extarnal aluminum "skunge".
              Last edited by Guest; 10-11-2006, 05:47 AM.

              Comment


                #8
                Originally posted by justin caise View Post
                Ironically, I just found a set or two of those bolt kits on eBay. Where to find the boots tho?
                Just go to ace or home depot or lowes for you allen screws.I like ace(westlakes hardware) the best.

                Comment


                  #9
                  Originally posted by Road_Clam View Post
                  90% of the time a hanging high idle is a result of an air leak or way mis adjusted air screws (also too lean).
                  ..you need to have your carbs DIPPED to completely clean all the tiny internal carb passage ways.
                  Yeah, but there's four of THEM, and only one of me!
                  I didn't touch the air screws so must be dirt or leak. I mean I didn't adjust anything.
                  I'm not contesting the theory but I can't seem to wrap my mind around how an air leak ( extra air) would cause high idle (extra fuel). Maybe it is a misconception to think that extra fuel automatically translates into higher revs. Does a rich idle mean a high idle? Not neccesarily, so I think I'm missing something here... wouldn't an air leak make a lean condition?

                  Originally posted by Road_Clam View Post
                  I had a non-idling #3
                  How did you know it was #3?

                  Skunge is a good word. I like that one. Maybe that's the bikes new name.
                  Last edited by Guest; 10-11-2006, 07:14 PM. Reason: because each post is like a motorcycle masterpiece - never finished

                  Comment


                    #10
                    Originally posted by justin caise View Post
                    Yeah, but there's four of THEM, and only one of me!
                    I didn't touch the air screws so must be dirt or leak. I mean I didn't adjust anything.
                    I'm not contesting the theory but I can't seem to wrap my mind around how an air leak ( extra air) would cause high idle (extra fuel). Maybe it is a misconception to think that extra fuel automatically translates into higher revs. Does a rich idle mean a high idle? Not neccesarily, so I think I'm missing something here... wouldn't an air leak make a lean condition?


                    How did you know it was #3?

                    Skunge is a good word. I like that one. Maybe that's the bikes new name.
                    More air than gas = hight idle and lean conditions.....More gas than air and you will bog down and foul the plugs

                    Comment


                      #11
                      Too much air also leads to running very lean which leads to very hot combustion and will overheat and destroy some very expensive components.

                      I'd post photos of the canyons carved into my old exhaust valves by a too-lean mixture caused by bad o-rings, but it's a sickening sight that doesn't belong in a family forum.
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                      Comment


                        #12
                        Yeah, it do run really hot now! I'll try the ol WD40 around the possible air leaks trick.

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