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GS550E 1980: Throttle hesitation. Stuck floats?

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    GS550E 1980: Throttle hesitation. Stuck floats?

    Just digging into a project bike (first time). I can get the bike started with the choke all the way out. Yet even after it warms up, the throttle kind of hesitates (twist throttle, let go, nothing happens right away then zoom it takes off and idles back down). I checked the throttle cable and it is tight. I have had others tell me that the floats are most likely stuck and I should either pull the bowls off or use something like Sea Foam to clean the carbs out. I would really like to not have to deal with the carbs right away if I have too. Does anyone have any suggestions, tips....

    Thanks

    #2
    Hesitation likely has little to do with floats. I vote for mixture screws improperly set. The general standard is 2.5 turns out but must always be tweaked and calibrated for any particular bike.

    You have CV carbs, right? The ones with the big, wide, 2x2 inch wide tops?

    You should do a carb sync and calibration. That oughta do it. You'll want to make sure that your air filter is in place and clean. You may also want to check your intake boots (between the carbs and engine) for leaks. You will also want to inspect your CV diaphragms for leaks. They are under the caps of the carbs. Be gentle with them and be sure to have them seated back like they were, with the tab in the notch made for it.

    Carb tuning instructions as per Earl:

    "high idle after carb synch?"

    On CV carbs, pilot fuel and air are combined into one mixture screw. I set the #3 carb to baseline vacuum using throttle plate adjustment, then set the mixture screw on it for highest idle rpm. Then set the idle adjustment knob to return to 1200 rpm idle. Re adjust throttle plate on #3 to 10 inHg vacuum. Then set the fuel/air pilots (mixture screws) on 1,2 and 4 to the same number of turns as #3. When you have 1200 rpm and #3 is drawing 10 inHg vacuum, you have your baseline and then can set 1,2 and 4 to draw the same vacuum as #3. Once #3 is set to base, you must not touch the idle adjustment knob again. Only when all 4 cylinders draw the same vacuum and rpm remains at 1200 may you change the overall idle rpm if you wish.

    Setting the mixture screws doesnt do you any good if you dont have the correct intake velocity (vacuum) for the screw setting. After you set up #3, that is why you cannot make any more changes with the idle adjustment knob. Its impossible to synch vacuums if youre constantly sending the reading all over the scale with the idle adjustment knob.

    Earl

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