1972 CB500 four running great then running terrible

[NathanBeswick]

Hey everyone,
I've got myself a 1972 cb500 four. when its running good it is running perfect but this doesn't happen very often. when cold it usually starts fine on full choke but won't idle when choke is off. i have adjusted idle screw but idle will not stay consistent. once warmed up its runs fine for a while but then starts to miss and lose power completely. fuel starts to pour out of overflow of carbi 1 when the bike is stopped when running not good. once the bike cuts out when hot it won't start again unless the choke is on. i have ordered new carbi kits, and rubber boots for both engine to carbis and carbis to air box. if anyone has any other ideas or any input would be appreciated
cheers

 

[HerrDeacon]

fuel starts to pour out of overflow of carbi 1 when the bike is stopped when running not good.

You need to get this addressed! Even if the bike is running good all the time, this is a recipe for trashing your engine if some of the gas gets into the engine oil. Chances are that that overflow could be the source of most or all of your running issues.