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bike still cuts off, now over-revving...

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  • bike still cuts off, now over-revving...

    so, my katana saga continues.....

    last week i replaced the missing plug inside my carbs. i had 3 plugs already, but was missing one for carb#3....

    Sorry for the huge pics, i don't know how to resize them..



    see the hole my finger is pointing to under the float assembly?


    anyone know the importance of this plug?

    anywho, until then, it's been running very rich. i was told by the local performance shop it was 'cause of that plug missing in the carbs, and 'cause i had K&N pod filters on there. so i replaced the plug, re-installed the stock airbox, and i replaced the spark plugs with new NGK's yesterday. it started right up, warmed up, but would not hold a constant idle. my choke slider sticks (i WD40'd it when the carbs were off, didn't help at all), so i have to push it all the way in manually. if i push it till i feel the slider stop, it keeps running, just not steady idling. if i give it one more good push to make sure it's all the way in, the engine cuts off, every single time. after it cuts off, i can start it back up, but if i barely push the slider again, it cuts off again. well, with it still running, i toyed with the idle screw and the lowest i could get the idle without immediate cut off was between 2-3K RPM. so i adjusted it best i could, and decided to take it up the street....

    out of the driveway i go, easing off the clutch, and BARELY giving it gas....then WWAAAAHHHHHHHH!!!!! the engine shoots to 9K RPM, and the bike almost flies out from beneath me! i held the clutch in as i hit a turn, eased on the throttle again and WAAAAHHHHHHHH!!!!!! revving like no tomorrow, when BARELY giving gas. so i keep revving the throttle to get it to come down as i proceed to coast around another turn. coming out the turn, i give it a hefty amount of throttle, and it goes like normal as long as i'm on the throttle a good bit. i'm on a backroad, so topping 2nd gear is about as far as i can get before i have to hit the brakes. coming to a stop, i pull the clutch in and it redlines, for just a second or two as i rev it to try and get it to come down. so i pulled into a parking lot and let it try to idle. WAAAAAHHHHHHHH!!!!! the needle goes to redline again, and this time i have to kill the engine 'cause it doesn't seem to want to stop. i tried to get it to crank again, it sputtered but wouldn't crank. so i had to push it back home, UPHILL after letting it sit for an hour, it cranked right back up. it didn't idle smooth still, and the gas was very very very touchy, but didn't redline this time. i just feathered the gas/clutch enough to get it on the carport... any suggestions? sorry for the long post, just trying to give a good explanation of my problems before i give up and have the shop pick it up for me..


    "If you ain't first, you're last..." - Ricky Bobby
    "Your stuck on an anger bridge man, you gotta cross the anger bridge and come back to the friendship shore..." - Magic Man

  • #2
    Well , I had a friend last year with carb problems . His bike wouldn't idle , so he kept turning up his idle screw . The bike would then idle normal , but as soon as he touched the gas it would rev to 7K and stay there . Soetimes it would come back down really slow . After messing with it for several weeks , and finally giving in and taking it to a shop , it was determined that his pilot jets were pretty clogged (after they had already been cleaned twice) . That's why it wouldn't idle , and the idle knob turned way up was why it would rev like mad . Just one possible explanation . You replace those plugs ? I'm not sure what they do either , but I imagine they're there for SOME reason .
    I am a fluffy lil cuddly lovable bunny , dammit !



    Katrider's rally 2011 - md86

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    • #3
      great info, thanks! i've had everything in the carbs cleaned also, but it's a possiblility they're still jammed up. as for the plug, yep, i replaced it last week. the yamaha/suzuki/kawa shop here gave me one for a super cc, but i dwiddled it down with a dremel to fit it.

      i really like your theory of the carbs/idle screw/throttle effect, gives me hope that there's nothing MAJOR wrong.. lol


      "If you ain't first, you're last..." - Ricky Bobby
      "Your stuck on an anger bridge man, you gotta cross the anger bridge and come back to the friendship shore..." - Magic Man

      Comment


      • #4
        Yeah , I tried to think of everything that would cause the symptoms my friend was experiencing , and he ended up buying like $1000 in parts ! I said "it COULD be an air leak from that hole in the airbox boot" , so he buys some K&N's ! Then he buys a jet kit and a full V&H exhuast (I'm not really sure what the logic was behind that ...) . After all this crap , it turns out he didn't clean his carbs as well as he thought he had !
        I am a fluffy lil cuddly lovable bunny , dammit !



        Katrider's rally 2011 - md86

        Comment


        • #5
          ok as far as the rubber plugs go there not that important now im sure everyone esle its gonna say yes they are i built a 771 motor and had a stage 3 kit with the pods just like you had the pods wont make your bike run rich if anything it will go lean if not jetted properly all the rubber plug do is cap off the idle jet port because theres a small orfice down inside the tube that the idle jet it suppose to draw fuel from the main jet passage thats why the main jet emultion tube has holes around the outside if you leave the rubber plugs out it just draws fuel from the bowl itself instead of the mian jet passaege and if you idling rich check the orings around your floats and check your needles too the rubber plugs being out wont make it run rich the idle jet will only pull as much fuel as its the air flow demand is. and yes it know all this because ive actually taken a carb and sliced it open with a band saw to see how all the ports and passages work.

          Comment


          • #6
            I'll take a little of this and that..
            you can clean the fuel mix jets ( the ones on the bottom in front of the carbs in situe but I don't recommend it ( i did it to #2 ) But I agree with MD86 you can unscrew the jet and hose it down
            with carb cleaner. The thing that I notice is missing is Carb Synch.. Mine behave very much like yours.
            I didn't belive it at first but #4 was so far out of whack is was nearly sucking the murcury out.
            1-3 were running 2-3 cm /hg vacuum #4 was 14 cm/hg!!!
            Once I got #4 tamed it started acting like a real engine and not a posessed two stoke..

            Comment


            • #7
              that's one thing i've been thinking all along, but with the fuel problems i had earlier it was harder to diagnose 'cause there were several things wrong at once (spark plugs, fuel petcock, dirty carbs, missing carb plug). i know a sign of carb synch is it not idling, or cutting off when you come off the choke, so i got my fingers crossed.. lol


              "If you ain't first, you're last..." - Ricky Bobby
              "Your stuck on an anger bridge man, you gotta cross the anger bridge and come back to the friendship shore..." - Magic Man

              Comment


              • #8
                I had this problem when I had a bad spring on one of my sliders and my carbs were not sync'd. HAve you checked the Air sie of the carbs to make sure all the parts are there? Also make sure the O-rings are good on the vaccuum ports (where you attach the manometer/carb sync tool). If you are missing one or one is messed up or in wrong, you will have similiar problems. Check that stuff if you haven't already and get 'em sync'd.

                We can go from there.
                AMA member # 224227

                Comment


                • #9
                  carb synch'ing isn't expensive, so i'm hoping that's what it is ($40 from local shop). if not, i'm gonna ask them to tear down my carbs for a thorough inspection. i'm not familiar with all the carb parts yet, so i get iffy about taking them apart lol


                  "If you ain't first, you're last..." - Ricky Bobby
                  "Your stuck on an anger bridge man, you gotta cross the anger bridge and come back to the friendship shore..." - Magic Man

                  Comment


                  • #10
                    They should be able to sync the carbs and set the fuel/air screws and idle scew if there are no other issues and fix you up. Let us know.
                    AMA member # 224227

                    Comment


                    • #11
                      definately!!!!


                      "If you ain't first, you're last..." - Ricky Bobby
                      "Your stuck on an anger bridge man, you gotta cross the anger bridge and come back to the friendship shore..." - Magic Man

                      Comment


                      • #12
                        Originally posted by takirb
                        carb synch'ing isn't expensive, so i'm hoping that's what it is ($40 from local shop). if not, i'm gonna ask them to tear down my carbs for a thorough inspection. i'm not familiar with all the carb parts yet, so i get iffy about taking them apart lol
                        Uh , you should be able to buy your own carb-synch gauge for that price . And it takes like 10 minutes to do ...
                        I am a fluffy lil cuddly lovable bunny , dammit !



                        Katrider's rally 2011 - md86

                        Comment


                        • #13
                          can you direct me to a link for that purchase? i thought good carb synch tools were expensive...


                          "If you ain't first, you're last..." - Ricky Bobby
                          "Your stuck on an anger bridge man, you gotta cross the anger bridge and come back to the friendship shore..." - Magic Man

                          Comment


                          • #14
                            +5 to md86..
                            Buy the tool for 40 and have free carb sych for life!!
                            The way my carbs were acting I never would have thought it was sych.. It was too wacky. But that is all it was..

                            I just read you can set the mix screws using a sychro.
                            Anyone have the settings for this?
                            Special K question??

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