Re-routed the fuel line, but still having warm start problems

Your carburetor needs attention. The float is almost certainly too heavy, being made out of foam and having absorbed gasoline. The inlet needle and seat are probably not sealing properly, too. Carburetor operation and repair manuals and links to training movies and carb repair/modification threads are posted here for free download. Tune-up parts and technique suggestions in this thread.

(And yes, you need to have the correct 5/16"-thick insulator gasket between the carburetor and the intake manifold)