Leaking carbgreenspun.com : LUSENET : CB550 : One Thread
I have a 74 cb550 with 8500 miles which is leaking fuel from one of the carbs. I have rebuilt the carbs over the weekend with the Keyster kit (of which I only used the rubber seal and the 100 jet and kept the other original parts), cleaned extensively (all of the jets were soaked in carb cleaner and the holes are unobstructed), the floats are at 22mm, but she still leaks fuel from one of the drain pipes. I also synchronized and timed it. It rides fine, has plenty of power, but is a little spotty (as if it doesn't get enough fuel) in the low rpm's. I played around with the air-mixture screws and they currently are out 1 1/4 turns. The plugs are pretty black indicating that it is running too rich. Another problem I have that it is really difficult to put her into neutral while standing and it is much easier to do it while still rolling. Thanks for listening. Cord
-- Cord Dueppe (email@example.com), July 01, 2002
try using the float needle and seat including in the carb kits. also pull the pin that holds the float in place and make sure there aren't any burrs on it that might be hanging up the float. if it is running rich then that will cause it to run spotty at low rpm's (lots of gas and not much air). try turning the air mix screw in slowly, and listen for the engine to start missing, then back it out until it runs faster keep going out until it misses again, then back in until it idles high and smooth again. that should be where you set the screw. do this for each carb, if one doesn't change rpm when doing this, then you need to raise the "idle" a little for that carb, then try it agin..or that air passage is clogged. take out the screw and use compressed air to blow it out, I use an air can for cleaning cameras (if you haven't access to a compressor, and they have nifty tubes like wd-40). I set my carbs up by eye and set them to 2 turns, worked great ran a whole season without mucking up the plugs...I work on 12 cylinder Ferarri's and this is the method for setting "6" 2 barrel carbs, thats 12 air mix screws. works like a charm best of luck and sorry for the long response
-- chris luciano (firstname.lastname@example.org), July 19, 2002.