need help diagnosing

Posted by 1982cb750scnighthawk on Jun 08, 2011; 8:55pm
URL: http://vintage-and-classic-hondas.81.s1.nabble.com/need-help-diagnosing-tp3041201.html

hey gang. nice to be here.
bought this bike a while back, was running fine. stored the bike for a year, and now it wont run properly.
I thought it was crappy gas so I replaced the petcock, drained and cleaned the tank, had the carbs sonic cleaned and inspected by a pro. reset idle screws at 1 3/4 turns. then for fun I changed the oil/filter, air filter, and replaced the plugs(gapped correct).

now the bike idles very rough at 1000rpm with the choke closed. when I open the choke the engine quits, even after bike warms up. If I touch the throttle the engine quits. If I start the bike (choke closed) with a little throttle, the bike will idle smoothly at 2000-2500rpm, as long as i hold the throttle. Either way if i open the choke, bike dies.

I`ve had the carbs out half a dozen times, to check them. floats ok(plastic), float valves ok, all jets clean and clear, no junk in float bowls, linkages working properly...nothing stands out as a problem. needles show some light wear, but bike guy said it was no problem.

I`m about to stick a fork in this thing...hope someone can help