My 1988 honda will not idle when warm we have rebuilt the carb. Replaced vacuum lines and still when it gets warm the engine wants to die it runs good when you are driving it. It only dies when you are idleing.

Thoughts:

The problem is likely with the idle circuit of the carburetor. When the engine is hot, is the choke pointing straight up and down? If not, check or replace the choke pulloff. Did you gently seat the idle adjusting screws and then back them out the proper number of revolutions (1-1/2?)? Make final adjustment later.

Did you remove and thoroughly clean the carburetor, blow it out with compressed air, and install a complete rebuild kit?